|Year : 2020 | Volume
| Issue : 7 | Page : 556-584
Perioperative fasting and feeding in adults, obstetric, paediatric and bariatric population: Practice Guidelines from the Indian Society of Anaesthesiologists
Pradeep A Dongare1, S Bala Bhaskar2, SS Harsoor3, Rakesh Garg4, Sudheesh Kannan5, Umesh Goneppanavar6, Zulfiqar Ali7, Ramachandran Gopinath8, Jayashree Sood9, Kalaivani Mani10, Pradeep Bhatia11, Priyanka Rohatgi12, Rekha Das13, Santu Ghosh14, Subramanyam S Mahankali15, Sukhminder Jit Singh Bajwa16, Sunanda Gupta17, Sunil T Pandya18, Venkatesh H Keshavan19, Muralidhar Joshi20, Naveen Malhotra21
1 Assistant Professor, Department of Anaesthesiology, ESIPGIMSR, Bengaluru, India
2 Department of Anaesthesiology, Vijayanagar Institute of Medical Sciences, Ballari, India
3 Professor, Department of Anaesthesiology, Dr BR Ambedkar Medical College and Hospital, Bengaluru, India
4 Additional Professor, Department of Onco-Anaesthesia, Pain and Palliative Medicine, DR BRAIRCH, AIIMS, New Delhi, India
5 Professor, Department of Anaesthesiology, BMCRI, Bengaluru, India
6 Professor, Department of Anaesthesiology, Dharwad Institute of Mental Health and Neurosciences, Dharwad, India
7 Associate Professor, Department of Anesthesiology and Critical Care, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, India
8 Professor and Head,Department of Anaesthesiology and Intensive Care, ESIC Medical College and Hospital, Hyderabad, India
9 Honorary. Joint Secretary, Board of Management, Chairperson, Institute of Anaesthesiology, Pain and Perioperative Medicine, Sir Ganga Ram Hospital, New Delhi, India
10 Scientist IV, Department of Biostatistics, AIIMS, New Delhi, India
11 Professor and Head, Department of Anaesthesiology and Critical Care, All India Institute of Medical Sciences, Jodhpur, India
12 Chief Clinical Dietician, Apollo Hospitals, Bengaluru, India
13 Professor and Head, Department Anaesthesiology, Critical care and Pain, Acharya Harihar Post Graduate Institute of Cancer, Cuttack, India
14 Assistant Professor, Department of Biostatistics, St John's Medical College, Bengaluru, India
15 Senior Consultant Anaesthesiologist, Aster R V Hospital, Bengaluru, India
16 Professor and Head, Department of Anaesthesiology and Intensive Care, Gian Sagar Medical College and Hospital, Punjab, India
17 Professor and Head, Department of Anaesthesiology, Geetanjali Medical College and Hospital, Udaipur, India
18 Chief of Anaesthesia and Surgical ICU, AIG Hospitals, Hyderabad, India
19 Senior Consultant and Chief, Department of Neuroanaesthesia and Critical Care, Apollo Hospitals, Bengaluru, India
20 Head, Department of Anaesthesia and Pain Medicine, Virinchi Hospitals, Hyderabad, India
21 Professor, Department of Anaesthesiology and In Charge Pain Management Centre, Pt BDS PGIMS, Haryana, India
|Date of Submission||05-Jun-2020|
|Date of Decision||20-Jun-2020|
|Date of Acceptance||22-Jun-2020|
|Date of Web Publication||01-Jul-2020|
Pradeep A Dongare
ESI-PGIMSR, Rajajinagar, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Dongare PA, Bhaskar S B, Harsoor S S, Garg R, Kannan S, Goneppanavar U, Ali Z, Gopinath R, Sood J, Mani K, Bhatia P, Rohatgi P, Das R, Ghosh S, Mahankali SS, Singh Bajwa SJ, Gupta S, Pandya ST, Keshavan VH, Joshi M, Malhotra N. Perioperative fasting and feeding in adults, obstetric, paediatric and bariatric population: Practice Guidelines from the Indian Society of Anaesthesiologists. Indian J Anaesth 2020;64:556-84
|How to cite this URL:|
Dongare PA, Bhaskar S B, Harsoor S S, Garg R, Kannan S, Goneppanavar U, Ali Z, Gopinath R, Sood J, Mani K, Bhatia P, Rohatgi P, Das R, Ghosh S, Mahankali SS, Singh Bajwa SJ, Gupta S, Pandya ST, Keshavan VH, Joshi M, Malhotra N. Perioperative fasting and feeding in adults, obstetric, paediatric and bariatric population: Practice Guidelines from the Indian Society of Anaesthesiologists. Indian J Anaesth [serial online] 2020 [cited 2021 Jul 24];64:556-84. Available from: https://www.ijaweb.org/text.asp?2020/64/7/556/288764
| Preamble|| |
Preoperative fasting involves being nil by mouth before surgical procedures requiring sedation or anaesthesia. In the postoperative period, complete avoidance of oral dietary intake is practiced, till recovery of bowel function for abdominal surgeries. Impairment or abolition of airway reflexes following deep sedation or anaesthesia can lead to pulmonary aspiration of gastric contents. The ideal condition for minimising the risk of regurgitation and aspiration is an empty stomach before deep sedation or anaesthesia, which may be impossible to achieve due to the continuous gastric secretory activity along with impaired physiology due to various aetiologies encountered in the preoperative period.
Traditional cut off points of gastric aspirate volumes of >25 mL with pH <2.5 have long been quoted to correlate with significant pulmonary aspiration leading to respiratory failure., This critical pH and volume was obtained by Roberts and Shirley on a Rhesus monkey and were extrapolated to humans. Although pH and gastric volume have been traditionally measured using aspiration techniques, the modern research modalities utilising pharmacokinetic properties of orally administered water-soluble substances such as paracetamol, magnetic resonance imaging (MRI) and scintigraphy have provided better insights into the physiology of gastric emptying. Newer modalities such as gastric ultrasonography (GUS) have been increasingly used to study the gastric volumes and emptying.
What is the need for the Indian Society of Anaesthesiologists (ISA) guidelines?
A large number of surgical procedures are conducted daily in India, with diverse health care settings and differing practice standards. The patient population varies in terms of food items consumed, with a variable fat content, caloric content and nutrient composition in different regions and states. The socio-cultural, geographic and economic factors also play a role in the food habits.
The overall culture and eating habits of the population is largely similar in countries of South Asia that includes India, Bhutan, Nepal, Bangladesh, Sri Lanka, Maldives, Afghanistan and Pakistan, but the available guidelines do not apply uniformly across these countries and very few evidences address the problems peculiar to this region. These issues have been taken into consideration during the formulation of 'Practice guidelines on perioperative fasting and feeding' by the ISA.
This document emphasises the concerns related to the safe duration of fasting before and after administration of sedation or anaesthesia for elective, diagnostic or surgical procedures. It addresses the type and quantity of solid and liquid food that can be ingested safely till the fasting is initiated and the feeding is restarted in the postoperative period. It covers the general surgical population, and those undergoing paediatric, obstetric and bariatric procedures. The guidelines are not applicable for subset of patients who have medical or surgical conditions which predispose them to aspiration.
These guidelines are developed based on the current evidence available worldwide and in India as also on the basis of institutional practice patterns across India, gathered from the countrywide survey conducted by the ISA. The guidelines are designed to steer the practice of anaesthesiology based on evidence, and cannot be taken as absolute or standard answers for specific research questions. The recommendations will be updated as and when additional evidence emerges in future.
Focus of the guidelines
These clinical practice guidelines provide recommendations for withholding solid and liquid food before elective diagnostic or surgical procedures performed under deep sedation or anaesthesia (regional or general) and for resumption of oral feeds in the post procedure period. They are aimed to reduce the incidence and severity of aspiration pneumonitis and other complications (such as hypotension during induction of anaesthesia), to prevent delays or cancellations of surgical procedures and also lead to a better patient outcome. The guidelines are addressed to practicing anaesthesiologists, surgeons, other medical and paramedical professionals involved in patient care.
It may also be useful for patients to know the types of food that are considered as clear liquids, non-clear liquids, light meal and heavy meal and to guide them in consumption of food items before presenting for elective diagnostic or surgical procedures. It will identify the shortcomings in the evidence specific to South Asian countries, and allow for the formation of institutional protocols and stimulate research among the colleagues so that evidence is added for the future.
| Methodology|| |
The ISA approved the proposal for preparation of the practice guidelines on perioperative fasting and feeding during the annual general body meeting of ISA in November 2017. The core committee consisted of the President and Secretary of ISA and six members. The expert committee consisted of 12 members, with academic standing and experience in the field of anaesthesiology and respective subspecialties from different institutions of India, along with two expert biostatisticians and one nutrition expert.
The core committee held meetings within the group (3 in-person and 25 online) and with members of the expert committee (2 in-person and 12 online) to discuss the research questions and the evidence available. The core committee formulated and circulated a validated survey questionnaire  for each section to institutions across India, to collect additional data regarding institutional fasting and feeding practices from those geographical regions. Surveys pertaining to paediatric, obstetric and bariatric patients were circulated to institutions offering services specifically to such groups. The evidence obtained from the expert committee members and the results from the survey were combined to formulate the draft guideline document. The same was presented at the annual conference of ISA (ISACON) in November 2019 in a special session involving the core committee, expert committee, delegates and ISA governing council members. The updated draft was presented to and approved by the general body of ISA.
Electronic search for full text articles published in English language before January 2020 was conducted, using keywords based on the research questions, in PubMed, Embase, Cochrane Library and Google Scholar databases: meta analyses, systematic reviews, randomised controlled trials (RCTs), observational studies, cohort studies, case series and case reports were included. Manual retrieval of the missing manuscripts from the bibliography of the published articles and guidelines was done. Narrative reviews, editorials and letters to editors or correspondence and other similar items including only abstracts were excluded.
Standard data extraction techniques from retrieved manuscripts were followed for subsequent meta-analysis. Research questions answered by at least 3 RCTs or observational studies fulfilling the Population; Intervention; Comparator; Outcome and Time frame (PICOT) criteria were included for meta-analysis. Additional data were collected for institutional fasting practices for adult population (from 56 institutions), for obstetric population (from 21 institutions), for paediatric population (from 13 institutions) and for bariatric population (from 18 institutions) from India, based on surveys using validated questionnaires. If meta-analysis was not possible for a research question, expert consensus was obtained based on the outcomes of available studies and the survey findings to arrive at a recommendation.
The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to allot the 'Level of Evidence' (LOE) of the literature included. The GRADE protocol categorises evidence into 'High, Moderate, Low and Very Low'. Based on these levels of evidence, recommendations were framed and graded as either weak or strong.
For the purpose of these guidelines, preoperative fasting is defined as the minimum required fasting duration for oral intake of solids or liquids prior to administration of anaesthesia or sedation necessary to minimise the risk of regurgitation and pulmonary aspiration in patients devoid of risk factors for regurgitation.
An empty stomach is a state when the gastric contents reach the baseline volume after the intake of a solid, semi solid or liquid meal. Baseline volume is defined as the volume of gastric contents of an adult after overnight fasting.
Residual Gastric volume is the volume of gastric contents at the time of examination or evaluation.
A full stomach is the presence of solid content or a state of increased volume of the liquid gastric contents above the baseline volumes after the intake of a solid, semisolid or liquid meal.
Clear liquid is defined as any liquid which takes <2 h to empty from the stomach in human beings.
Non-clear liquid is defined as any liquid which takes between 2 h and 4 h to empty from the stomach in human beings.
Light meal is defined as any food item which takes between 4h to 6h to empty from the stomach in human beings.
Heavy meal is defined as any food item which takes >6 h to empty from the stomach in human beings.
The summary of recommendations is represented as a table [Table 1].
| Adult Section|| |
What is the acceptable residual gastric volume?
Roberts et al. found that instillation of 25 mL of gastric aspirate into the right bronchus of rhesus monkey produced significant aspiration pneumonitis. Extrapolating this finding to humans, they stated that aspiration of 25 mL would produce pneumonitis and postulated that residual gastric volume of more than 25 mL posed a high risk for aspiration pneumonitis. Many studies tried defining the residual gastric volume, based on values obtained by actual aspiration (during endoscopy or by gastric tube) and by imaging techniques. More recent studies have used GUS to quantify the residual gastric volumes after fasting. The stratifications related to duration of fasting, definition of residual gastric volume and its assessment methods in existing studies have been inconsistent, limiting the attempts for formulation of acceptable definitions for clinical practice.
Perlas et al. in a prospective descriptive study using GUS found that 86 of the 200 patients fasted for 8 h for solids and 5 h for liquids had no or minimal residual gastric volume, while seven patients had a high residual gastric volume of 180 ± 83 mL. One among these with gastro-oesophageal reflux disease aspirated the gastric contents during extubation. Van de Putte et al. performed a retrospective analysis of 512 patients and classified patients as 'empty stomach' (no contents or liquid content <1.5 mL/kg) or 'full stomach' (liquid content >1.5 mL/kg or presence of solid content) based on GUS; they found that despite adhering to the American Society of Anesthesiologists' fasting guidelines, 32 patients had full stomach by this criteria. The mean fasting duration in these patients was 10.8 h and 13.9 h for liquids and solids, respectively. Eight patients had consumed heavy meals out of the nine patients who had solid content while one each of them had gastro-oesophageal reflux disease and Parkinson's disease. Four studies involving pregnant women found residual gastric volumes to be higher than 25 mL.,,,
Based on the current evidence, the traditional cutoff point of more than 25 mL residual gastric volume as a risk factor for aspiration pneumonitis may need to be re-examined in adults.
Adequate fasting times – When is the stomach empty?
Twenty one studies describing gastric emptying times of various kinds of foods were identified.,,,,,,,,,,,,,,,,,,,, Of these, 14 were RCTs and 7 were observational studies. These studies used various methods of gastric emptying estimation such as the 'gold standard' scintigraphy, MRI, GUS and carbon dioxide breath analysis. Most studies were performed on healthy volunteers involving small sample sizes. Six studies each were performed on gastric emptying of liquids of varying composition, solids of varying content, and combination of solid with liquid or meals, respectively while one study each consisted of semisolids and comparison of solids versus liquids, respectively. These studies showed significant variations in gastric emptying. A study in the Indian setting published in 1999 concluded that addition of spice (masala) to idli reduced the gastric emptying time.
The inferences drawn from these studies are as follows:
- The gastric emptying time is different for liquids, solids and semisolids. For solids it depended on the method of cooking, particle size and composition
- Clear liquids of low caloric value take approximately 2 h to empty
- Liquids with high caloric value and non-clear liquids may take longer than 2 h to empty
- Combinations of solids and liquids take anywhere between 4 and 7 h to empty
- Fried food items of similar composition take longer time to empty
- Scintigraphy cannot be used to estimate the residual gastric volume
- GUS estimation of residual gastric volume is computed by mathematical models based on the cross-sectional area of the gastric antrum, where return to baseline values is considered as gastric emptying time.
The categorisation of food items by the survey into heavy meals, light meals and clear liquids was reviewed by an experienced dietician after referring to the available evidence [Appendix 1], [Appendix 2], [Appendix 3].,,,,,,,,,,,,,,,,,,,,,,,,,,,,, The classification was revised by the dietician based on the duration of emptying of the stomach contents as clear liquids, non-clear liquids, light meal and heavy meal [Table 2].
|Table 2: Classification of food items into clear liquids, non-clear liquids, light meal, heavy meal|
Click here to view
Clear liquid 2 h before induction of anaesthesia vs overnight fasting
The stomach always has a basal volume due to continuous gastric secretions. The duration of fasting is considered acceptable if the post prandial gastric volume returns to basal levels. The 20 studies identified by our search regarding clear liquids intake and gastric volumes did not report any event of aspiration or regurgitation.,,,,,,,,,,,,,,,,,,, The studies were of Low, or Very Low level of evidence. In eight studies, after overnight fasting, one group received water to consume medications and the other, received between 100 and 500 mL water till 2 hours before induction of anaesthesia.,,,,,,,
Residual gastric volume considerations
The meta-analysis of three studies conducted using studies published between1988 and 2016, comparing consumption of water 2 h prior to induction of anaesthesia and overnight fasting found that the groups who had consumed water 2 h prior had comparable residual gastric volumes with a mean difference of 0.76 mL and 95% CI 0.60 to 1.02 (LOE- Moderate).,,
Studies comparing consumption of other clear liquids such as orange juice, black coffee with overnight fasting were analysed separately (LOE- Very Low to Low). The meta-analysis of six such studies published between 1988 to 2016 showed that the residual gastric volumes were comparable between the two groups of patients with a mean difference of 1.04 mL and 95% CI of 0.90 mL to 1.2 mL) (LOE- Moderate).,,,,,
The meta-analysis of 4 studies conducted between 1988 to 2016 showed a lower gastric pH in patients fasted overnight compared to those allowed water 2 h before the induction of anaesthesia with a mean difference of 1.0 and 95% CI of 1.07 (LOE- Moderate).,,, The meta-analysis of 5 studies found higher gastric pH after administration of clear liquids other than water 2 h before the induction of anaesthesia compared to overnight fasting with a mean difference of 1.08 and 95% CI of 0.98 to 1.19, while network meta-analysis showed the pH to be higher in groups allowed to consume clear liquids when compared to water (LOE-Moderate).,,,,
Residual gastric volumes and pH considerations from other studies
Scarr et al. conducted an observational study in patients scheduled for ambulatory surgeries and classified 181 patients into 4 groups based on the duration of fasting (<3h, 3-4.9 h, 5-8 h and >8 h) and found similar gastric volumes and pH in all the groups. The participants in the study were asked not to consume solid food from midnight and were asked to consume 150 mL liquid (coffee, tea, water or apple juice) 1 h before leaving home (LOE- Very Low).
A study using Technetium 99 to assess the emptying of clear liquids showed that the patients receiving carbohydrate containing solutions had gastric volumes comparable with patients receiving water at 90 min and at 120 min (LOE- Very Low). Other studies which compared residual gastric volumes and pH after consumption of different kinds of liquids showed comparable gastric volumes and pH (LOE- Very Low to Low).,,,,,, In a study assessing gastric volumes by gastroscopic aspiration after consumption of 200 mL water, the patients fasted for 40 to 75 min had gastric volumes similar to those fasted for 80-150 min (LOE- Moderate). An earlier meta-analysis also concluded that there was no evidence that patients given liquid (including water, coffee, fruit juice, clear liquids and other drinks, e.g., isotonic drink, carbohydrate drink) 2-3 h prior to surgery had increased incidence of aspiration or regurgitation (LOE- High). Newer commercially available carbohydrate containing clear liquids such as maltodextrin preparation (a polysaccharide), have been used as a part of the enhanced recovery after surgery (ERAS) protocol; the residual gastric volumes and gastric content pH have been found to be comparable to those after over-night fasting (LOE- Very Low). Gomes et al. compared the residual gastric volumes using gastric ultrasonography after administration of 12.5% maltodextrin and a combination of 12.5% maltodextrin and glutamine. They found that the addition of glutamine did not increase the residual gastric volume 2 h after administration in healthy volunteers (LOE- Very Low).
Volume of clear liquids allowed
An RCT by Soreide et al. found comparable gastric volumes after administration of 20 mL, 150 mL and 300-450 mL of water 1-2 h before surgery (LOE- Very Low). Similarly, comparable residual gastric volumes were found between overnight fasting patients and those receiving 100–500 mL clear liquids 2 h before surgery in other studies conducted in patients scheduled for elective surgical procedures (LOE-Very Low to Low).,,,,,,,,,,,,,,,,,,,
The average fasting times for solids, liquids and clear liquids as per the survey respondents from 56 institutions were 7.43 ± 1.65 h, 5.68 ± 1.90 h and 3.16 ± 2.33 h, respectively.
Clear liquids should be allowed up to 2 h prior to administration of sedation or anaesthesia.
The volume of clear liquid consumed may be restricted to <450 mL, 2 h prior to administration of sedation or anaesthesia.
Non-clear liquids may be allowed up to 4 h prior to administration of sedation or anaesthesia.
Light meals may be allowed up to 6 h prior to administration of sedation or anaesthesia.
If the patient has consumed heavy meals, it may be prudent to wait for at least 10 h prior to administration of sedation or anaesthesia.
Heavy meal consumption is not advisable the night prior to surgery.
Various drugs have been used with the purpose of either increasing the pH, decreasing the volume of gastric contents or both and the studies on these drugs have measured residual gastric volumes by using aspiration from gastric tubes. The commonest drugs that have been used are H2 receptor blockers, proton pump inhibitors, non-particulate antacids such as sodium citrate and prokinetic drugs like metoclopramide. This section examines if the routine use of aspiration prophylaxis will benefit the patient.
Residual gastric volume considerations
H2 receptor blockers
The meta-analysis of 3 studies showed no decrease in the residual gastric volume with the administration of oral H2 receptor blockers (cimetidine and ranitidine) compared to placebo with a mean difference of 1.51mL and a 95% CI of 1.02 to 2.23 (LOE- Moderate).,, A small sample study by Salempara et al. showed a significant decrease in the residual gastric volume after administration of oral cimetidine either 300 mg or 600 mg 2 h before surgery (LOE- Very Low). Morison et al. conducted a study involving an intravenous phase and oral phase. There was no difference in the residual gastric volume in the intravenous phase but in the oral phase, lower residual gastric volumes were observed when ranitidine was administered 2 h before the surgery (LOE- Very Low). Similar results were found by Maile et al. with intravenous administration of ranitidine 1–2 h before surgery. Three studies found patients with gastric volumes more than 25 mL even after administration of oral H2 receptor blockers (LOE- Very Low).,, Similar studies conducted with different dosage regimens of H2 receptor blockers, timing and routes of administration have yielded conflicting results.,,,,, Overall, the evidence does not point to uniform observations of reduction in the residual gastric volume after administration of H2 receptor blockers.
Proton pump inhibitors
The meta-analysis of 3 studies comparing residual gastric volumes after administration of proton pump inhibitors and placebo yielded a mean difference of 3.31 mL with a 95% CI of +2.34 to 4.68 (LOE- Moderate).,, Mehta et al. conducted a study comparing three different proton pump inhibitors and found that the residual gastric volumes were comparable among them (LOE- Very Low).
H2 receptor blockers vs proton pump inhibitors
The meta-analysis of 4 studies comparing residual gastric volumes after the administration of either drug showed a mean difference of 1.68 mL and a 95% CI of 1.44 to 1.95 (LOE- Moderate).,,, Nishina et al. conducted two studies in 1996 and 2000 comparing different proton pump inhibitors and ranitidine and found least residual gastric volumes (per kg body weight) when ranitidine was administered as a single dose on the morning of surgery (LOE- Very Low)., Levack et al. achieved a gastric volume of <25 ml and pH >2.5, in 84% of patients receiving either ranitidine or omeprazole, when administered the night before and early morning of surgery and 73% of patients who received a single equivalent dose of omeprazole on the morning of surgery (LOE- Low). Dattatraya et al. conducted a similar study and none of the (n = 50 in each group) patients receiving either ranitidine or proton pump inhibitors (omeprazole, esomeprazole, pantoprazole) had residual gastric volume >25 mL in both the H2 receptor blocker and the proton pump inhibitor groups (LOE- Very Low).
Two meta-analyses concluded that H2 receptor blockers were better than proton pump inhibitors to reduce the gastric volume., Puig et al. in a meta-analysis including 18 publications with different schedules of administration and routes of administration, found that patients receiving H2 receptor blockers were at lower risk of aspiration (as per criteria laid down by Shirley and Roberts) (LOE- High).) Clark et al. in another meta-analysis including 7 RCT's found that the gastric volumes were lower and gastric content pH was higher in groups who received H2 receptor blockers (LOE- High).
H2 receptor blockers, Proton pump inhibitors and prokinetic drugs
The meta-analysis of 3 studies showed no significant difference in residual gastric volumes between the placebo group and those who received H2 receptor blocker with prokinetic drugs with a mean difference of 2.15 mL and 95% CI of 1.63 to 2.97 (LOE- Moderate).,, Manchikanti et al. conducted two studies which showed that there was a significant reduction in the residual gastric volume after administration of H2 receptor blocker with prokinetic drugs in comparison to either of the drugs administered alone (LOE-Very Low)., Dimich et al. conducted a study in patients coming for ambulatory surgeries and found that there were significantly higher residual gastric volumes in patients who received H2 receptor blockers compared to those who received H2 receptor blockers with prokinetic drugs (LOE- Low). Gombar et al. in a study on 80 patients coming for surgery, found reduced gastric residual volumes on administration of a combination of proton pump inhibitors and prokinetic drugs when compared to H2 receptor blockers and proton pump inhibitors administered alone (LOE- Very Low).
Non-particulate antacids and H2 receptor blockers
Six studies showed that the gastric volumes were higher when non-particulate antacids (sodium citrate) were administered when compared with controls or H2 receptor blockers (LOE- Very Low to Low).,,,,,
Anticholinergics are the other group of drugs postulated to reduce the residual gastric volume by decreasing the gastric secretion. Three studies using atropine or glycopyrrolate administered alone did not show much difference in the residual gastric volumes (LOE-Very Low to Low).,,
H2 receptor blockers
The meta-analysis of three studies (with oral cimetidine and ranitidine) showed that the pH was slightly higher in patients receiving H2 receptor blockers compared to placebo with a mean difference of 0.41 with 95% CI of 0.33 to 0.50 (LOE- Moderate).,, Other studies which compared H2 receptor blockers in varying doses or dosage regimen found similar increase in the pH of residual gastric contents (LOE- Very Low to Low).,,,,,,,,,,
Proton pump inhibitors
The meta-analysis of 3 studies showed an increased gastric pH in patients receiving proton pump inhibitors with a mean difference of 0.94 and a 95% CI of 0.11 to 1.77 (LOE- Moderate).,, Mehta et al. compared three proton pump inhibitors and found a raised gastric pH with all three groups (LOE- Very Low).
H2 receptor blockers vs proton pump inhibitors
The meta-analysis of 4 studies showed the pH of gastric contents to be higher with proton pump inhibitors with a mean difference of 0.6 and a 95% CI of -0.08 to +1.28 (LOE- High).,,, The studies involving more than two groups (comparing different drugs or dosages or dosage regimen) also showed similar results (LOE- Very Low to Low).,,,,,,
Seven studies showed that prokinetic drugs when used alone did not have any effect on the pH of gastric contents (LOE- Very Low to Low).,,,,,,
Non-particulate antacids and H2 receptor blockers
The gastric pH was raised in all patients receiving non-particulate antacids and was comparable to H2 receptor blockers.(LOE- Very Low to Low),,,,,, Foulkes et al. compared gastric content pH after administering no drug, oral cimetidine 300 mg and 0.3 M sodium citrate 30 mL (n = 15 in each group) and found that all patients had a pH of more than 2.5 after receiving sodium citrate (LOE- Very Low to Low).
Use of anticholinergics was not found to cause any significant change in the pH of gastric contents (LOE- Very Low).,,
Most of the respondent institutions advised aspiration prophylaxis for all patients scheduled for surgery (44.64%). Further, 42.86% of institutions advised aspiration prophylaxis for at risk patients and 10.71%, for emergencies only. The remaining 1.79% of institutions did not use any prophylaxis. Seventy one percent of the respondents used H2 receptor blockers as aspiration 18 prophylaxis, 70% prokinetic drugs, 57% proton pump inhibitors, 54% 5HT3 receptor antagonist, 9% sodium citrate (0.3 M) and 5% used others. Those who chose the option 'others' mentioned dexamethasone, additional prokinetic drugs and multiple drugs.
Routine use of aspiration prophylaxis in adequately fasted patients is not advised prior to administration of sedation or anaesthesia.
Aspiration prophylaxis is advised in high-risk patients as identified by the anaesthesiologist.
H2 receptor blockers, proton pump inhibitors and prokinetic drugs may be used as prophylaxis in high-risk patients.
Postoperative oral feeding in Adult patients
The research into the postoperative feeding in general adult surgical population revealed association of multiple factors (LOE- Very Low). The wide variability in the surgical procedures performed and the techniques involved influences the decision on resumption of postoperative feeding. Systematic reviews and meta-analysis have been performed for specific surgeries like colorectal surgeries or lower abdominal surgeries.,
The respondents felt that the mean time for allowing clear liquids postoperatively was 4.0 ± 2.3 h and for solids was 8.6 ± 7.0 h.
In view of lack of quality evidence and variability in the time of resumption of oral feed as per our survey no recommendations can be made in the general adult surgical population.
Chewing gum, alcohol consumption and smoking have been explored with regards to their effect on gastric emptying and residual gastric volume in the perioperative fasting period. A meta-analysis of 4 studies, RCTs and observational studies showed that there is no difference in the residual gastric volume or gastric emptying whether patients had chewed gum or not in the preoperative period (LOE- Very Low to Low).,,,, However, in an analysis of incidents in the webAIRs Australian incident reporting system, chewing gum was found in the mouth of 5 patients during induction of anaesthesia. It may be important to ensure that patients spit out chewing gum before the administration of anaesthesia or sedation (LOE- Low). Chewing gum in the postoperative period is not common practice in India. A Cochrane review and 1 other meta-analysis have found early return of bowel function with chewing gum in the postoperative period (LOE- Low)., Another meta-analysis of 12 studies and other RCTs have found the results to be equivocal (LOE- Low to Moderate).,,,
Studies conducted on the effect of alcohol (6% vs 10%, 3 units vs 6 units, beer, wine, 50% ethanol) on gastric emptying have been equivocal. Studies on varying concentrations of alcohol have found that overall alcohol consumption may delay the gastric emptying of solid food (LOE- Very Low to Low).,,,
Effect of smoking, chewing nicotine gum and nicotine patch on gastric emptying and residual gastric volume have been studied. Acute cigarette smoking has been found to delay the gastric emptying of solid and liquid food (LOE- Low)., However, a study on the effect of nicotine patch on the gastric emptying of solids and liquids did not find any delay (LOE- Very Low). A study using ultrasonography did not find any difference in the residual gastric volumes after acute cigarette smoking (LOE- Very Low).
| Obstetric Section|| |
Is the incidence of aspiration higher in pregnant women scheduled for elective procedures?
Studies performed in various settings (patients scheduled for cervical encirclage, caesarean sections, manual removal of placenta, medical termination of pregnancy, under general anaesthesia) were included. The level of evidence of most of these studies was low. The meta-analysis of 5 studies yielded a combined incidence of aspiration of 29/1,00,000 (95% CI was 7/1,00,000 to 120/1,00,000) (LOE- High).,,,, In a case series published by Dureja et al., two cases of aspiration were identified. Of these two one was in a patient who had presented to the emergency with history of trauma and bleeding per vagina. Pulmonary aspiration was suspected when intra-operatively the patient developed increased resistance to ventilation under general anaesthesia (LOE- Very Low).
The responses from 21 institutions, dedicated to obstetric anaesthesia services showed that only 42.7% institutions considered pregnant women to be at higher risk for aspiration in the perioperative period.
Women in early or late pregnancy when administered sedation or general anaesthesia may be considered to be at high risk for aspiration.
Appropriate fasting times in pregnant women.
Seven comparative trials ,,,,,, related to gastric emptying and 2 RCT's , related to residual gastric volume or comparison of gastric antral areas in pregnant women were accessed. The methods of assessment of gastric emptying included phenol red dye method, potential tomography, GUS and breath analysis after lactulose and paracetamol absorption. The studies used varying quantities of meal; most of the studies were done with clear liquids and some with light meal consumption. The meta-analysis of 5 studies estimating gastric emptying of liquids in pregnant women compared to non-pregnant women showed that liquids took longer time to empty from the stomach in non-pregnant women with a mean difference of 2.06 min and 95% CI of -1.28 to +5.40 (LOE- High).,,,, Wald et al. found prolonged oro-caecal transit times in pregnant patients (LOE- Very Low). Cholioro et al. found prolonged half emptying times for liquids in first trimester and term pregnancy compared to 4–6 months after delivery (LOE- Very Low). Wong et al. conducted two studies in 2002 and 2007, both comparing consumption of 300 mL and 50 mL water with pregnant women in one study and obese pregnant women in another. They found reduced half times with consumption of 300 mL water in both studies (LOE- Low)., Three observational studies based on ultrasonographic estimation of the cross-sectional area found comparable outcomes between pregnant women scheduled for caesarean section and non-pregnant women (LOE- Low to Moderate).,,
One observational study showed a residual gastric volume >1.5 mL/kg in 23–52% pregnant women with more than 36 weeks of gestation. (LOE- Very Low). There were no studies comparing the gastric emptying of solid food.
Hong et al. in a randomised control trial including 200 patients compared the residual gastric volume and pH between term pregnant women coming for Caesarean sections and women coming for gynaecological surgeries and found that the mean gastric volume was higher (0.49 ± 0.4 mL/kg vs 0.24 ± 0.2 mL/kg ) and mean gastric content pH was lower (2.4 ± 1.4 vs 3.0 ± 1.9 ) in pregnant women in comparison to non- pregnant women (LOE- Low).
The participant obstetric anaesthesia units across India advocate similar fasting times for both pregnant and non-pregnant women.
Thus, in pregnant women, the duration of preoperative fasting for different kinds of foods is the same as in non-pregnant women
Clear liquids may be allowed up to 2 h prior to administration of sedation or anaesthesia in pregnant women.
Non-clear liquids may be allowed up to 4 h prior to administration of sedation or anaesthesia in pregnant women.
Light meals may be allowed up to 6 h prior to administration of sedation or anaesthesia in pregnant women.
If the pregnant woman has consumed a heavy meal, it may be prudent to wait for at least 10 h prior to administration of sedation or anaesthesia.
Heavy meal consumption is not advisable the night prior to surgery in pregnant women.
Routine aspiration prophylaxis in pregnant women
Residual gastric volume considerations
We identified 12 comparative trials (including one from India),,,,,,,,,,,, 2 systematic reviews , and 3 surveys ,, on aspiration prophylaxis in obstetric units. The studies had low level of evidence due to small sample sizes and varied drugs employed for prophylaxis. The studies examined usage of sodium citrate, H2 receptor blockers, prokinetic drugs and proton pump inhibitors alone or in combinations. Qvist et al. found that the administration of H2 receptor blocker in pregnant women resulted in a marginal decrease in the residual gastric volume compared to those who did not receive the drug (LOE- Very Low). Dewan et al. compared sodium citrate administered <60 min before versus >60 min before induction of anaesthesia and they found that patients administered sodium citrate >60 min before induction had a lower gastric content pH. The residual gastric volumes were comparable between the groups (LOE- Low). Sullivan et al. found that the residual gastric volume was reduced in pregnant women receiving ranitidine and metoclopramide compared to those receiving ranitidine, metoclopramide or magnesium trisilicate alone (LOE- Very Low). Studies comparing the use of sodium citrate and H2 receptor blockers, particulate antacids and use in elective vs emergency surgeries, have found that they increased the pH of gastric content but the residual gastric volumes are also increased (LOE-Very Low to Low).,,,,, Studies comparing the effect of proton pump inhibitors and H2 receptor blockers on residual gastric volume found that the volumes were lower when H2 receptor blockers and proton pump inhibitors were administered the night before and morning of surgery than when administered only on the morning of surgery (LOE- Very Low to Low).,,
Different methods of assessment of pH in pregnant patients were used in the studies included in our search. Among the drugs, sodium citrate, particulate antacids, H2 receptor blockers and proton pump inhibitors were found to raise the pH of gastric contents. Addition of metoclopramide to ranitidine had no effect on the pH. The pH levels were comparable when H2 receptor blockers or proton pump inhibitors were used. (LOE-Very Low to Low).,,,,,,,,,,,
Two systematic reviews , (LOE- Moderate) found no benefit of routine prophylaxis with any of these drugs. But, a systematic review by Paranjothy et al. on interventions to prevent aspiration pneumonitis in 2658 patients undergoing caesarean sections under general anaesthesia found that the combination of antacids and H2 receptor blockers was more effective than no intervention, and superior to antacids alone in preventing low gastric pH. Most of the surveys done across the United Kingdom and Australia between 1987 and 1994 found that routine aspiration prophylaxis was preferred (LOE- Very Low).,,
All respondent obstetric units in the survey except one, administered aspiration prophylaxis in pregnant women (both for emergency and elective indications) scheduled for caesarean section. Only one institution did not provide aspiration prophylaxis for women undergoing caesarean section under regional anaesthesia. Ten units administered routine prophylaxis out of 18 units for women receiving labour analgesia. The commonest drugs administered were ranitidine and metoclopramide.
Pregnant women requiring sedation or anaesthesia should be administered aspiration prophylaxis.
H2 receptor blockers, proton pump inhibitors either alone or in combination with prokinetic drugs can be administered for aspiration prophylaxis.
Post-operative oral feeding in patients after caesarean section
The 20 studies ,,,,,,,,,,,,,,,,,,, were heterogeneous with respect to anaesthetic techniques used (regional anaesthesia, general anaesthesia or both) and the timing of surgery (emergency or elective). Sips of water or liquid diet was used for resumption of oral feed in majority of the studies.,,,,,,,,,, Few of the studies targeted resumption of normal diet or solid food.,, Studies have used various parameters and outcomes such as time to appearance of bowel sounds, time to passage of flatus and incidence of ileus among others while discussing about resumption of oral feeds postoperatively. The time to initiation of early oral feed varied from 30 min to 8 h after surgery. The delayed feeding was based either on the appearance of bowel sounds or a fixed time frame postoperatively.
Time of post-operative oral feed and time to appearance of bowel sounds
The meta-analysis of 5 studies (including patients who had undergone caesarean section under spinal anaesthesia or general anaesthesia) showed that the mean difference in the appearance of bowel sounds was 7.93 hours longer with a 95% CI of 2.20 to 13.65 in the conventionally (12–24 h) fed group than in the early (6–8 h) fed group (LOE- Moderate),,,, Teoh et al. found bowel sounds immediately postoperatively in 95.9% patients at 30 min in the early feed group and in 90.8% patients at 30 min in the control group. The occurrence of bowel sounds was not an outcome measure in this study (LOE- Very Low). But, Mawson et al. found 87% of the patients to have bowel sounds the morning after surgery in the early feeding group (sips of water 6–8 h after caesarean section) and in 44.8% patients in the conventional feeding group (sips of water 12 h after caesarean section) (LOE-Low).
Time of post-operative oral feed and time to passage of first flatus
Twelve studies estimated the time to passage of flatus in post caesarean section patients after administration of different kinds of intake.,,,,,,,,,,, The meta-analysis of 4 studies in post caesarean section patients showed consumption of sips of water 6–8 h after surgery resulted in shorter time to passage of flatus with a mean difference of 9.91 h and a 95% CI of 3.57 to 16.25 compared to those allowed sips of water 12–24 h after surgery (LOE- Moderate).,,, Other studies where the time to passage of flatus after solid food or food given earlier than 6 h showed similar results.,,,,,,,
Incidence of ileus and other factors
The meta-analysis of 8 studies combining the incidence of ileus at 24 h showed a relative risk of 1.08 with a 95% CI of 0.81 to 1.45. There was no significant difference in the incidence of ileus between patients who had been given oral feed between 6 and 8 h and those who received feed at 12–24 h (LOE- High).,,,,,,, The incidence of nausea, vomiting, abdominal distension, length of hospitalisation, maternal satisfaction, etc., were comparable between groups of patients who had early initiation of feed to delayed initiation of feed across most of the studies. Meta-analysis and systematic reviews by other authors also yielded similar results (LOE-High),,,,
Evidence pertaining to oral consumption of liquids after obstetric interventions other than caesarean section are sparse and no meaningful conclusions can be drawn about the same. Studies of very low level of evidence have even advocated postoperative feeding as early as 2 h. Experts were of the opinion that oral feed can be allowed at a shorter duration than 8 h. This allows for further scope for research.
The time to initiation of oral feeds in the postoperative period by respondent obstetric units was 6.1 ± 7.7h for liquids after central neuraxial block, 6.0 ± 6.6 h for liquids after general anaesthesia, 12.7 ± 14.2 h for solids after central neuraxial block and 13.3 ± 14.2 h for solids in patients who had undergone caesarean section under general anaesthesia.
Clear liquids can be allowed orally 8 h after caesarean section under regional/general anaesthesia.
Gastric emptying in immediate postpartum period
Women in the postpartum period (from delivery to 12 weeks) may present for procedures (e.g., sterilisation). Whitehead et al. in a study comparing gastric emptying times using paracetamol absorption technique found that there was no difference in pregnant women and women on the 1st, 2nd or 5th day postpartum (LOE- Very Low). Gin et al. in a study on 8 women in the postpartum period found that the gastric emptying was rapid on the first and third postpartum day and comparable to gastric emptying in 6 women who came for follow-up after 6 weeks (LOE- Very Low). Lam et al. compared residual gastric volume and gastric content pH in non-pregnant women (n = 50), women in the postpartum period who had fasted overnight (n = 50) and women in the postpartum period who had consumed clear liquids 2 h prior (n = 50). They found that the median residual gastric volumes and pH were comparable among all three groups (LOE- Very Low).
Women in post-partum period may not be any different from general adult population with regard to gastric emptying times and pH.
Studies found that women who chewed gum in the immediate postoperative period after caesarean sections had shorter times to passage of flatus, return of bowel sounds (LOE- Very Low to Low).,,,,,,,
| Paediatric Section|| |
Factors predisposing children for regurgitation and aspiration
Seven studies evaluated the factors predisposing children for regurgitation and aspiration.,,,,,, A meta-analysis of 49 studies involving 1457 children (28 weeks of gestation to adulthood) reinforced the significance of food type in modulating gastric emptying and found that aqueous solutions had faster gastric emptying compared to solids (45 min vs 98 min) (LOE - High). Children aged 3–17 years maybe at a higher risk of aspiration as their gastric residual volume was >0.4 mL/kg. All except one child had gastric content pH <2.5 (LOE-Very Low). Children (6 months to 18 years) were found to have greater risk for acid aspiration than adults (18–64 years) and geriatric (>64 years) population as children have a greater gastric residual volume and lower gastric content pH.
The prevalence of reflux regurgitation was highest at 2 months of age (86.9%) which decreased to 7.6% by 1 year of age in Thai children. A study on 1000 consecutive day care surgery children (2–12 years) found that preoperative acetaminophen and midazolam increased gastric fluid volume (GFV) while lower GFV was associated with ASA physical status III, male gender, gastroesophageal reflux disease, and proton pump inhibitor administration. All had GFV >0.4 mL/kg despite standard fasting protocols. (LOE–Low).
Incidence of aspiration in children
The meta-analysis of 8 studies published between 1998 and 2019 with a total sample size of 4, 26, 594 patients yielded an incidence of 49/1,00,000 aspirations in children with a 95% CI of 30/1,00,000 to 81/1,00,000 (LOE–High).,,,,,,, The Anaesthetic Incident Monitoring Study reported 133 cases of aspiration in children <14 years out of the total 240 incidents of aspiration. Only 17 of these children were inadequately fasted (LOE – Very Low). The main reasons attributed to aspiration included emergency surgery, medications, inadequate anaesthesia. A case series involving three children showed one child developing aspiration despite adequate fasting (LOE–Very Low).
A total of 10 units that exclusively catered for paediatric anaesthesia and one department that catered to obstetric and child population participated. They reported 72 cases of regurgitation, 31 cases of regurgitation with aspiration and eight cases of aspiration pneumonitis perioperatively in children undergoing elective surgeries. Similarly, 91 cases of regurgitation, 34 cases of regurgitation with aspiration and 14 cases of aspiration pneumonitis were reported in children undergoing emergency surgeries. Most children recovered with oxygen therapy. There were three deaths in children scheduled for emergency surgery attributed to regurgitation and aspiration.
Gastric emptying time in children
GUS evaluation showed that the emptying time in 48 healthy volunteers (8–14 years) for apple juice, 2% milk and Ensure ® Clear was 3-3.5 h (LOE- Low). Expressed breast milk emptied twice as fast as formula milk in preterm infants in a GUS study (LOE- Low). An MRI study in children found gastric emptying of clear liquids had a median half-life of <30 min (LOE- Low). Gastric emptying for cow's milk was similar in both healthy children and those with GERD (LOE- Low). Prolongation of liquid gastric emptying half-time was observed with increasing severity of GERD (LOE- Low). The adult normative data for gastric emptying for solids may be inappropriate for children (5–18 years) (LOE- Low). In a serial GUS study on stable preterm infants, breast milk composition was found to influence gastric emptying, with feeds of higher casein content emptying faster while fortified mother's milk emptying much slower than unfortified mother's milk (LOE- Low). Another GUS study on preterm infants fed with fortified, unfortified and pasteurised human milk found reduced percentage of gastric retention with higher casein, whey and lactulose concentrations in the milk. They also found that curdling did not affect emptying (LOE- Low). In a GUS study on children <5 years, it was found that 100 mL milk up to 3% fat and clear liquid 100 mL with 17.5% dextrose can be safely given 3 h and 2 h prior to anaesthesia, respectively (LOE- Low). Children (8.2–12.5 years) consuming 7 mL/kg of raspberry syrup had a gastric emptying half time of 27 min compared to 20 min in those who consumed 3 mL/kg of the same in an MRI based volunteer study (LOE- Low). The average gastric emptying half-time was 49 ± 23 min, 54 ± 29 min and 65 ± 36 min for breast milk, half-fortified breast milk and fully fortified breast milk respectively (LOE- Low). The mean gastric emptying half-time was 107.2 min for 30 g of chocolate crispy cake among children (5–10 years, LOE – Very Low). The calculated mean gastric emptying time was <4 h (236 min) following breakfast in pre-schoolers in a study using serial ultrasonographic measurements (LOE – Very Low).
Consumption of water 1 h prior vs 2 h prior to induction of anaesthesia
Residual gastric volume considerations
The meta-analysis of 3 studies involving 307 children aged 1–16 years, found that the residual gastric volume was comparable between groups consuming water at 1 hour or >2 h prior to the induction of anaesthesia with a mean difference of 1.46 mL and a 95% CI of 0.77 to 2.97 (LOE - High).,,
No difference in gastric pH was found in two studies where children aged 1–16 years were allowed to consume clear liquid at premedication or 1 h prior compared to consumption of water 2 h prior to induction of anaesthesia (LOE – Moderate).,
Other Clear Liquids (2 h vs >2 h prior to induction of anaesthesia)
Residual gastric volume considerations
The meta-analysis of 5 studies found that the residual gastric volume was lower in children who consumed clear liquids containing calories at 2 h prior to induction of anaesthesia compared to those who consumed at an interval of more than 2 h with a mean difference of 0.77 mL with a 95% CI of 0.47 to 1.27. Two of these studies were performed in infants and one study compared residual gastric volume and pH after consumption of water or breast milk. Three other studies involved infants and children up to 14 years of age (LOE – High).,,,,
In a study of 120 children (2–18 years) scheduled for gastroscopy, consumption of lemon-flavoured carbohydrate beverage reduced the mean volume of gastric contents compared to water or tea administered 2 h prior to induction of anaesthesia (LOE – High). The residual gastric volume was comparable when 6 or 10 mL/kg apple juice was consumed 2.5 h before induction of anaesthesia compared to overnight fasting in children aged 5–10 years (LOE – Moderate).
No significant difference in gastric pH was found in the meta-analysis of five studies (2 in infants and 3 in infants and children aged up to 14 years) comparing pH after clear liquid consumption at 2 h or >2 h before induction of anaesthesia with a mean difference of 0.97 and a 95% CI of 0.85 to 1.09 (LOE – High).,,,, The gastric pH was comparable in children 2–18 years age both with consumption of lemon-flavoured carbohydrate beverage or non-carbohydrate beverage (water or tea) 2 h prior to the procedure (LOE – Moderate). Comparable pH was found when 6-10 mL/kg apple juice was consumed 2.5 h before induction of anaesthesia compared to overnight fasting in children aged 5–10 years (LOE – Moderate).
Fasting times for formula feeds and solids
Children <9 months of age given formula feeds at 4-6 h Vs 8 h prior to induction of anaesthesia showed comparable residual gastric volume (LOE – Moderate). In a crossover MRI trial, children (6.8–12.2 years) when given a light breakfast consisting of cereal flakes and milk products at 4 h had a higher gastric volume when compared to the same given at 6 h (LOE – Low). Weight corrected gastric residual volumes in 22 children who had fasted < 6 h was comparable to 46 children who had fasted >6 h in children (0.3–19.6 years) scheduled for MRI (LOE – Very Low).
The evidence showed a large variability in the age of the subjects studied (neonates - 18 years).
Regarding the appropriate fasting time for different kinds of food items, most of the respondents opined that 2 h was appropriate for clear liquids, 4 h for human milk, 6 h for cow's milk and 6 h for formula feed or solids. Three of the 11 respondents who answered the question on volume of clear liquid allowed in children felt that 3 mL/kg was the appropriate volume. Two others felt that there was no limit. The rest felt that 10 mL/kg, 20 mL, <50 mL and 100 mL were appropriate, and 1 respondent felt that no specific volume was recommended.
Consumption of water, up to 3mL/kg should be allowed until 1 h prior to administration of anaesthesia.
Consumption of clear liquids other than water, up to 3 mL/kg can be allowed until 2 h prior to administration of anaesthesia.
Human milk and fully skimmed non-human milk can be allowed until 4 h prior to administration of anaesthesia.
Non-clear liquids, non-human milk, formula feeds, light breakfast or light meal may be allowed until 6 h prior to administration of anaesthesia.
Aspiration prophylaxis in children
Domperidone reduced gastric emptying in preterm neonates (LOE –Low). Oral ranitidine with or without liquids resulted in a decrease in both volume and acidity of gastric contents (LOE – Moderate). Low dose erythromycin appears to be safe and effective in decreasing gastric emptying in preterm babies born after 34 weeks of gestation in the first two weeks of life (LOE – Moderate). Oral ranitidine hydrochloride 2 mg/kg is effective in increasing the pH of gastric aspirate in children aged one to six years in the majority of patients though one should expect lack of measurable response in some children (LOE – High). Gender, age, gastrointestinal pathology or pH-altering medication does not appear to have an effect on the GFV (LOE – Very Low). Thus, as per the evidence, aspiration prophylaxis may not be uniformly effective in improving the gastric pH and reducing the residual gastric volume in adequately fasted children.
The attending anaesthesiologist can decide for or against the administration of aspiration prophylaxis in adequately fasted children.
Fasting practices in children scheduled for procedural sedation
Out of a total of 149046 sedation procedures evaluated for the incidence of aspiration,,,,, only one study reported aspiration events (10 instances) (LOE – Low), while other four studies found no instances of aspiration in any of the children despite many children not meeting the standard fasting criteria prior to procedural sedation (LOE – Low).,,, Overall, 30,306 children did not meet standard fasting criteria out of 148935 known cases of fasting duration (LOE – Low).,,,, A survey among Canadian paediatric emergency departments reported that only 53% physicians follow standard fasting guidelines for children undergoing procedural sedation. The physicians were less likely to perform procedural sedation immediately if a child had a full meal <2 hours ago or liquids <1 hour ago. Those with 6–10 years of experience were more willing to perform immediate procedural sedation in such situations. Physicians who had an institutional fasting policy reported disinclination towards performing immediate procedural sedation (LOE – Very Low). The evidence shows that the fasting guidelines are not strictly followed for procedural sedation in paediatric patients. In low resource settings the decision on the duration of fasting for procedural sedation will be influenced by set up and the level of expertise of the attending anaesthesiologist.
The attending anaesthesiologist can decide on the duration of fasting for procedural sedation within operating room or remote location.
Postoperative oral feeding practices in children
In a study involving children (6 months–4 years), early resumption of oral intake (apple juice 10 mL/kg) in the post anaesthesia care unit after the Face Leg Activity Cry Consolability (FLACC) score was ≥4, following anaesthesia was associated with reduced incidence of postoperative vomiting and a decrease in opioid consumption compared to those kept fasting till return to ward. (LOE – Moderate). The postoperative fasting times were significantly greater in children less than 17 years scheduled for complex surgical procedures than those undergoing non-complex procedures. Most patients received some postoperative fasting time, even when it was not ordered by the physician in the diet order (LOE – Very Low).
Most respondents (of the 10 units) felt that resumption of clear liquid intake can be started at 1–2 h, human milk at 3–4 h, formula feed at 4–6 h, and cow's milk at 4–6 h after surgery.
The oral consumption of clear liquids in the postoperative period should be resumed at the earliest where no medical or surgical contraindications exist.
Effects of prolonged fasting duration in children
Observational studies and surveys found the duration of preoperative fasting is prolonged in 60-70% of the children posted for surgery (LOE – Very Low).,,, In a study comprising of 1350 children (2-16 years) with a median fasting time of 12.05 hours, 56% were found to be very hungry or starving, while 27% of the children were very thirsty (LOE – Very Low). Children <36 months showed higher concentration of plasma ketone bodies and lower mean arterial pressure immediately after anaesthetic induction following prolonged duration of fasting. But there was no significant difference in the plasma glucose concentrations (LOE – Moderate).
Overnight fasting, breast milk (LOE – Moderate), or infant milk formula NAN (Nestle Australia Ltd.) consumed 3-4 h preoperatively (LOE –Moderate) or administration of lactated Ringer's solution as intraoperative maintenance fluid (without dextrose containing solutions) were not associated with perioperative hypoglycaemia. In a retrospective study on 238 children who had undergone MRI under propofol sedation, the duration of fluid abstinence did not correlate with the decrease in the blood pressure. In an observational study in 100 children aged 2–6 years scheduled for ophthalmic examination under sevoflurane anaesthesia, it was found that the prolonged duration of fasting correlated with emergence delirium scores at 15 and 25 min after the procedure (LOE – Very Low). In a cohort study including 404 children undergoing bone marrow biopsy under general anaesthesia, it was found that the exposed group (those fasted for >3 h) had a higher incidence of postoperative vomiting (LOE – Very Low). But there was no correlation to the incidence of hypoglycaemia. In a prospective interventional study (of approximately 16,000 children), effects of utilising quality improvement methodology to reduce excess fasting times, with a goal of achieving experienced clear liquid fasting times ≤4 h for 60% of patients was studied. Use of active language encouraging drinking; clear liquids allowed up until arrival to operating room (30 min prior to arrival time); providing water or apple juice in preoperative holding area and addition of sports drinks to allowable clear liquids, resulted in an improvement with compliance to fasting duration for clear liquids (LOE – Low).
If the duration of fasting was more prolonged than recommended, 62% of the respondents assessed for hypoglycaemia, 38% felt that they had to look for hypotension. Thirty eight percent also felt that they had to assess for irritability, dry tongue, blood sugar if neonate or administered liquids.
| Bariatric Section|| |
Obese individuals are considered to be at higher risk of aspiration, with a high body mass index (BMI) correlating with acid reflux.,,,,, Increased transient lower oesophageal sphincter relaxation (TLOSR) with acid reflux has been reported in 2-hour postprandial oesophageal manometry in obese and overweight subjects when compared with a non-obese subjects.
The meta-analysis of 3 RCTs comparing the gastric emptying half-time for liquids in obese and non-obese individuals found that the gastric emptying half times were comparable with a mean difference of 4.78 min and a 95% CI of -13.09 to +3.54 (LOE- Low).,, Similar studies comparing gastric emptying time of solids have shown equivocal results with some showing a prolonged overall gastric emptying time (LOE- Very Low).,,,,,,,
The meta-analysis of 5 RCTs comparing residual gastric volume in obese and non-obese individuals showed that obese individuals have a slightly higher residual gastric volume compared to non-obese individuals with a mean difference of 2.47 and a 95% CI of 0.24 to 4.71(LOE- High).,,,, The meta-analysis of 4 RCTs comparing gastric content pH showed that obese individuals had lower pH when compared to non-obese individuals with a mean difference of 2.92 and a 95% CI of -5.57 to - 0.31 (LOE- High).,,,
An RCT including 126 adult obese individuals (excluding those with gastro-oesophageal reflux, hiatus hernia and diabetes mellitus) fasted from midnight found that the residual gastric volume and pH in the control group were comparable to the study group administered 300 mL. liquid (water, apple juice, black coffee, clear tea, carbonated beverages) 2 h before surgery. They concluded that drinking clear liquid as per guidelines may not increase the risk of aspiration in obese patients (LOE- Very Low). Peura et al. in a post hoc analysis of patients enrolled in phase 3 studies comparing use of dex-lansoprazole and placebo or lansoprazole found that the symptom severity due to acid reflux increased with BMI and hence, they derive greatest benefit from treatment with proton pump inhibitors (LOE- Low). Lam et al. compared the residual gastric volume and gastric content pH in morbid obese patients scheduled for gastric stapling and found that administration of intravenous cimetidine 60–90 min before the procedure reduced the residual gastric volume and increased the gastric content pH (LOE- Low). A similar study compared the effect of cimetidine and ranitidine with or without the administration of metoclopramide on the residual gastric volume and gastric content pH in morbidly obese patients scheduled for gastroplasty and found that the residual gastric volumes and gastric content pH were comparable among all the groups (LOE- Very Low). In a study evaluating the effect of combinations and different doses of ranitidine and metoclopramide, they found that 300 mg of oral ranitidine the night before and morning of surgery combined with metoclopramide 10 mg the morning of surgery reduced the residual gastric volume to the greatest extent. The pH was comparable among the study groups and higher than the control group (LOE- Very Low). Mahajan et al. compared the residual gastric volume and gastric content pH in lean and morbidly obese patients with or without the administration of ranitidine and metoclopramide as prophylaxis in patients who had fasted for 8 hours prior to elective surgery. They found that the residual gastric volume was lower in lean individuals and those morbidly obese individuals who had received prophylaxis (LOE- Low).
Our survey found that 66.7% of the respondents administer aspiration prophylaxis to all obese individuals while 16.7% of the respondents administer only in patients with reflux symptoms; 77.8% of the respondents chose H2 receptor blockers as the first choice for administration as prophylaxis.
Obese individuals may be considered to be at higher risk for aspiration in comparison to non-obese individuals when administered sedation or anaesthesia.
In obese individuals, the advice on preoperative fasting practices may be the same as in non-obese individuals prior to the administration of sedation or anaesthesia.
Aspiration prophylaxis may be administered in obese patients prior to the administration of sedation or anaesthesia.
H2 receptor blockers, proton pump inhibitors either alone or in combination with prokinetic drugs can be administered for aspiration prophylaxis.
Postoperative oral feeding practices in obese patients after bariatric surgery
Matlok et al. in an analysis of 170 patients in an observational study (who underwent either laparoscopic Roux en Y procedure or sleeve gastrectomy) found that oral liquid was well tolerated by 128 patients when administered within 5 h of postoperatively. Oral administration of liquid was tolerated by 162 patients within the first 24 h (LOE- Very Low). There is insufficient evidence to formulate a recommendation for the resumption of postoperative feeding in this subset of patients.
The mean time for resumption of oral feed in bariatric patients calculated from the data from the 18 respondents were 12.1 ± 8.9 h for clear liquids for restrictive procedures and 14.7 ± 11.9 h for malabsorption procedures. The mean time for resumption of solid food was 119.8 ± 162 h for restrictive and 123.4 ± 160.2 h for malabsorption procedures, respectively.
| Role of Gus as Preoperative Tool for Assessing Gastric Content|| |
Identification and differentiation of stomach contents
Most studies on identification of antral contents with GUS were observational or experimental in nature performed on different subset of patients such as pregnant women, children and in patients undergoing elective/emergency surgery.
Six healthy volunteers (fasting for 8 h) evaluated with GUS on four occasions, after consumption of 200 mL apple juice or 200 mL 2% milk or a standard solid meal (sandwich and apple juice) confirmed the ability of GUS in identifying empty stomach, and in differentiating clear liquid from viscous liquid or solid content (LOE- Low). In 20 healthy volunteers, the post prandial state of the stomach was identified by 2 well-trained emergency medicine residents and 1 attending physician on 73% and 65% occasions with the volunteers in right lateral decubitus (RLD) and supine positions respectively. However, after consumption of 16 ounce of water, the stomach could be visualised 100% of the times. (LOE- Low). The GUS could differentiate fasted from non-fasted (liquids/solids) states with high sensitivity (85% for all) and specificity (93% and above for all) in a volunteer cross over study (LOE- Low). The GUS could easily differentiate the contents of the stomach in pregnant women (LOE- Moderate). A sensitivity as high as 1 and a specificity as high as 0.975 was established in a study with GUS in 40 patients who underwent 80 examinations by experienced sonologists (LOE- Moderate). Similar study found that the mathematical model used by them was reliable in obese patients when volumes of up to 400 mL were administered
(LOE- Very Low). Antrum could be identified in 95% and 90% of obese patients in RLD and supine positions respectively. The study also found larger antral areas and basal gastric volume in these patients (LOE-Very Low). The cut off values for empty stomach in children after induction of anaesthesia were found to vary in the supine and RLD positions, with the latter having the highest sensitivity and specificity (LOE- Low).
GUS has been shown to be a valuable tool in influencing the induction/intubation technique with respect to risk of aspiration in infants with pyloric stenosis, children, adults and critically ill patients (LOE- Low).,,,, A study found that 6/100 patients (4 chronic kidney disease, 1 obese, 1 no co-morbidities) scheduled for elective surgery had 'full stomach' by GUS despite prolonged fasting durations (10–15 h) indicating that 10 h fasting duration does not assure an empty stomach (LOE- Very Low). An observational GUS study on 246 patients with average fasting duration of 7.75 h for elective and 7.345 h for emergency procedures found 69 patients to be at risk of aspiration (solid food or liquid content >1.5 mL/kg). A positive association was found between the risk of aspiration and GERD (LOE- Very Low).
Quantifying liquid content in the stomach
A study concluded that antral cross-sectional area (CSA) of <8 cm 2 might indicate an empty stomach in patients without GERD (LOE- Very Low). Interindividual variability in the gastric volume estimate with GUS after administration of equal amounts of liquid was high with minimal intrasubject variability after a meal (LOE- Very Low). The median fasting antral area was 4.2 cm 2 (range 2–16 cm 2) and volume of aspirated juice varied from 5 to 200 mL with correlation between antral area measurements and aspirated volume (LOE- Very Low). GUS in 24 normal newborns and eight newborns with suspected gastric retention [mean age 10.8 days) showed CSA >1 cm 2 after a nasogastric feed (milk) of >10 mL (LOE- Very Low). Estimation of gastric volume from antral area correlated better with the actual gastric volume than when estimated from the body or fundus up to 300 mL in the lateral decubitus position (LOE- Very Low). An area of 340 mm 2 coincided with the residual gastric volume of 0.8 mL/kg (considered high risk by the authors) (LOE- Very Low). MRI evaluation of gastric content volumes in children (6.4–12.8 year) found best correlations of antral volumes by GUS in RLD position (LOE- Very Low). The gastric volumes up to 500 mL estimated from antral CSA by GUS measured in RLD position strongly correlated with volumes aspirated by gastroscopy in non-pregnant adults with a BMI <40 kg/m 2 (LOE- Very Low). A gastric CSA >9.6 cm 2 corresponded with a high gastric volume (1.5 mL/kg) in third trimester pregnant women (LOE- Very Low). Song et al. in a study in children aged 18 years administered 10–15 mL/kg of carbohydrate containing solution 2 h before anaesthetic induction and were able to identify and measure the contents of the stomach in all 79 individuals. They quantified the stomach in terms of cross-sectional area. They did not correlate with the volume of liquid ingested (LOE- Very Low). Moser et al. in a study tried to estimate the cut off values for empty stomach in children after induction of anaesthesia. They found that the cut off point varied in the supine and right lateral decubitus position. The latter had the highest sensitivity and specificity. They quoted the antral cross-sectional area to be 3.07 cm 2 (LOE - Low). In a cohort study including 200 children aged between 1 and 16 years, Bouvet et al. found the prevalence of at risk stomach (defined as volume >1.25 mL/kg) to be 1% in adequately fasted children scheduled for elective surgery (LOE- Low). Arzola et al. developed a predictive model in term pregnant women scheduled for caesarean section under neuraxial anaesthesia after standard fasting instructions. They found no solid food in the stomach. Total of 53 women were in grade 0, 49 in grade 1 and 1 had grade 2 as per Perlas grading. Ninety-five per cent of the women presented with an antral area of <9.6 cm 2 (corresponding to an estimated volume of <1.5 mL/kg) (LOE- Low). In a similar study Amaral et al. found that the median for the gastric antral cross-sectional area was 4 cm 2 in 85 pregnant women. The 95th percentile was 10.3 cm 2. The gastric antral area correlated well with the body weight and the BMI (LOE- Very Low). Zieleskiewicz et al. conducted a study on parturients after administration of 0.4 mL/kg, 0.8 mL/kg and 1.5 mL/kg of water and tried to find the gastric antral area correlating best with the volume consumed. They found that the cut off value for detecting gastric fluid of >0.4 mL/kg, >1.5 mL/kg was 387 mm 2 and 608 mm 2 respectively in the supine position (LOE- Low). Roukhomovsky et al. conducted a similar study in 35 pregnant women and found that the cut off point of 505 mm 2 and the qualitative Perlas grading of grade 1 stomach combined predicted gastric volumes of >1.5 mL/kg better than either of these parameters used alone (LOE- Low).
Reliability of GUS compared to other methods of estimation of residual gastric volume
Reliability of GUS to assess gastric emptying and the residual gastric volume has been studied. The studies which describe the gastric emptying half time have used scintigraphy or serial ultrasonographic measurements. Scintigraphy measures the gastric emptying half time using residual radioactivity with time, whereas serial ultrasonographic measurements determine the reduction in the estimated gastric volume with time. Holt et al. found that the graphs for gastric volumes assessed serially were comparable between scintigraphy and ultrasonographic measurements (LOE- Low). Liu et al. found that trans-abdominal ultrasonography is similar in accuracy to scintigraphy in this regard (LOE- Low). Hveem et al. showed a comparable sensitivity to scintigraphy in quantifying emptying of both low and high nutrient liquids (LOE- Very Low). Darwiche et al. found good correlation in gastric emptying measured by ultrasonography and scintigraphy in diabetic patients (LOE- Very Low).
In another study by Sharma V et al. the volumes estimated by ultrasonography correlated well with aspirated gastric content volumes in 19 patients admitted to the Intensive Care Units (LOE- Very Low). Schmitz et al. found that the gastric antral CSA in RLD position with GUS were comparable with MRI in 18 volunteer children (LOE- Very Low). The aspirated gastric volume by gastroscopy was comparable for up to 500 mL of ingested volumes in non-pregnant patients with a BMI < 40 kg/m2 and the reliability of antral area assessments assessed by repeated estimations showed a coefficient of variation of 5.8%.,
Of the 56 respondents only one routinely assessed the gastric volume preoperatively. Nine respondents (16.07%) assessed the gastric volume preoperatively in patients they considered at risk. Forty-six respondents (82.14%) did not routinely assess the gastric volume. Of these only 5 respondents used ultrasonography to measure the gastric volume.
Gastric ultrasonography may be used as a bedside tool for assessing the quality and quantity of gastric contents in the preoperative period.
The quality and quantity of gastric contents should be assessed in the right lateral decubitus position.
The guidelines formulated are based on evidence and are applicable in their respective patient population. The summary of the guidelines are represented in [Table 1]. Overall, the guidelines suggest optimal time for consumption of food prior to the administration of anaesthesia. These guidelines will be updated as and when new evidence arises.
The authors gratefully acknowledge the contributions of the following in the preparation of the manuscript and content validation of the survey responses: Dr J V Divatia (Mumbai); Dr Venkatagiri (Kasargod); Dr Kuchela Babu V (Vishakapatnam); Dr Devaraj I C (Ballari); Dr Aloka Samantaray (Tirupati); Dr Ashok Jadon (Jamshedpur); Dr Parthasarathy S (Puducherry); Dr Pooja Bihani (Jodhpur); Dr Priyam Saikia (Guwahati); Dr. Rajesh M C (Calicut); Dr Rudrashish Haldar (Lucknow); Dr Sabyasachi Das (Kolkata); Dr Vandana Mangal (Jaipur); Dr Ayya Syama Sundar (Hyderabad); Professor Alka Chabbra (Udaipur), Professor Seema Partani (Udaipur); Dr Manish Kohli (New Delhi); Dr Ashwin Marwaha (New Delhi); Dr Rukhsana Najeeb (Srinagar); Dr Abdul Hamed (Baramulla); Dr Gayatri Vishwakarma (New Delhi); Dr Swarna H (Bengaluru); Dr Nischal Molkeri (Bengaluru); Dr Sneha S (Bengaluru); Dr Karthik H V (Bengaluru); Dr Vithal Kulkarni (Bengaluru); Mr Prakash Bisht (New Delhi).
Financial support and sponsorship
This Guidelines project is fully supported and Sponsored by Indian Society of Anaesthesiologists.
Conflicts of interest
There are no conflicts of interest.
| References|| |
Maltby JR. Fasting from midnight—the history behind the dogma. Best Pract Res Clin Anaesthesiol 2006;20:363-78.
Bisgaard T, Kehlet H. Early oral feeding after elective abdominal surgery— What are the issues? Nutrition 2002;18:944-8.
Brady M, Kinn S, Stuart P. Preoperative fasting for adults to prevent perioperative complications. Cochrane Database Syst Rev 2003;CD004423. doi: 10.1002/14651858.CD004423.
Edwards G, Morton HJV, Pask EA, Wylie WD. Deaths associated with anaesthesia. A report on 1000 cases. Anaesthesia 1956;11:194-220.
Bannister WK, Sattilaro AJ. Vomiting and aspiration during anesthesia. Anesthesiology 1962;23:251-64.
Roberts RB, Shirley MA. Reducing the risk of acid aspiration during cesarean section. Anesth Analg 1974;53:859-68.
Dongare PA, Bhaskar SB, Harsoor SS, Kalaivani M, Garg R, Sudheesh K, et al
. Development and validation of a questionnaire for a survey on perioperative fasting practices in India. Indian J Anaesth 2019;63:394-9.
] [Full text]
Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 The Cochrane Collaboration, 2011. Available from: www.handbook.cochrane.org. [Last updated on 2011 Mar]. [Last accessed on 2019 Nov 26].
Perlas A, Davis L, Khan M, Mitsakakis N, Chan VWS. Gastric sonography in the fasted surgical patient: A prospective descriptive study. Anesth Analg 2011;113:93-7.
Van De Putte P, Vernieuwe L, Jerjir A, Verschueren L, Tacken M, Perlas A. When fasted is not empty: A retrospective cohort study of gastric content in fasted surgical patients. Br J Anaesth 2017;118:363-71.
Arzola C, Perlas A, Siddiqui NT, Carvalho JCA. Bedside gastric ultrasonography in term pregnant women before elective cesarean delivery: A prospective cohort study. Anesth Analg 2015;121:752–8.
Hakak S, McCaul CL, Crowley L. Ultrasonographic evaluation of gastric contents in term pregnant women fasted for six hours. Int J Obstet Anesth 2018;34:15-20.
Gal O, Rotshtein M, Feldman D, Mari A, Hallak M, Kopelman Y. Estimation of gastric volume before anesthesia in term-pregnant women undergoing elective cesarean section, compared with non-pregnant or first-trimester women undergoing minor gynecological surgical procedures. Clin Med Insights Women's Health 2019;12:1179562X1982837. doi: 10.1177/1179562X19828372.
Van de Putte P, Vernieuwe L, Perlas A. Term pregnant patients have similar gastric volume to non-pregnant females: A single-centre cohort study. Br J Anaesth 2019;122:79-85.
Gentilcore D, Hausken T, Horowitz M, Jones KL. Measurements of gastric emptying of low- and high-nutrient liquids using 3D ultrasonography and scintigraphy in healthy subjects. Neurogastroenterol Motil 2006;18:1062-8.
Ziessman HA, Chander A, Clarke JO, Ramos A, Wahl RL. The added diagnostic value of liquid gastric emptying compared with solid emptying alone. J Nucl Med 2009;50:726-31.
Lobo DN, Hendry PO, Rodrigues G, Marciani L, Totman JJ, Wright JW, et al
. Gastric emptying of three liquid oral preoperative metabolic preconditioning regimens measured by magnetic resonance imaging in healthy adult volunteers: A randomised double-blind, crossover study. Clin Nutr 2009;28:636-41.
Okabe T, Terashima H, Sakamoto A. Determinants of liquid gastric emptying: Comparisons between milk and isocalorically adjusted clear fluids. Br J Anaesth 2015;114:77-82.
Okabe T, Terashima H, Sakamoto A. What is the manner of gastric emptying after ingestion of liquids with differences in the volume under uniform glucose-based energy content? Clin Nutr 2017;36:1283-7.
Benini L, Brighenti F, Castellani G, Brentegani MT, Casiraghi MC, Ruzzenente O, et al
. Gastric emptying of solids is markedly delayed when meals are fried. Dig Dis Sci 1994;39:2288-94.
Stotzer PO, Fjälling M, Grétarsdóttir J, Abrahamsson H. Assessment of gastric emptying: Comparison of solid scintigraphic emptying and emptying of radiopaque markers in patients and healthy subjects. Dig Dis Sci 1999;44:729-34.
Hsu CC, Chen PY, Chen CC, Pan LK. Measurement of gastric emptying time of solids in healthy subjects using scintigraphic method: A revised technique. Radiat Prot Dosimetry 2012;150:405-14.
Somasundaram VH, Subramanyam P, Palaniswamy SS. A gluten-free vegan meal for gastric emptying scintigraphy: Establishment of reference values and its utilization in the evaluation of diabetic gastroparesis. Clin Nucl Med 2014;39:960-5.
Vasavid P, Chaiwatanarat T, Pusuwan P, Sritara C, Roysri K, Namwongprom S, et al
. Normal solid gastric emptying values measured by scintigraphy using asian-style meal: A multicenter study in healthy volunteers. J Neurogastroenterol Motil 2014;20:371-8.
Coletta M, Gates FK, Marciani L, Shiwani H, Major G, Hoad CL, et al
. Effect of bread gluten content on gastrointestinal function: A crossover MRI study on healthy humans. Br J Nutr 2016;115:55-61.
Liu Z, Liu Z, Li Y, Guo J, Li J, Ren W, et al
. Evaluation of gastric emptying by transabdominal ultrasound after oral administration of semisolid cellulose-based gastric ultrasound contrast agents. Ultrasound Med Biol 2018;44:2183-8.
Achour L, Méance S, Briend A. Comparison of gastric emptying of a solid and a liquid nutritional rehabilitation food. Eur J Clin Nutr 2001;55:769-72.
Sagar S, Grime JS, Little W, Patten M, Gulliford P, Critchley M, et al
. Technetium-99m labelled bran: A new agent for measuring gastric emptying. Clin Radiol 1983;34:275-8.
Søreide E, Hausken T, Søreide JA, Steen PA. Gastric emptying of a light hospital breakfast: A study using real time ultrasonography. Acta Anaesthesiol Scand 1996;40:549-53.
Zinsmeister AR, Bharucha AE, Camilleri M. Comparison of calculations to estimate gastric emptying half-time of solids in humans. Neurogastroenterol Motil 2012;24:1142-5.
Tseng PH, Wu YW, Lee YC, Cheng MF, Tzen KY, Wang HP, et al
. Normal values and symptom correlation of a simplified oatmeal-based gastric emptying study in the Chinese population. J Gastroenterol Hepatol 2014;29:1873-82.
Sugita M, Matsumoto M, Tsukano Y, Fukunaga C, Yamamoto T. Gastric emptying time after breakfast in healthy adult volunteers using ultrasonography. J Anesth 2019;6-9. doi: 10.1007/s00540-019-02694-6.
Cho E-A, Kim MS, Cha YB, Lee M-S, Song T. Evaluation of Gastric Emptying Time of a Rice-Based Meal Using Serial Sonography. Biomed Res Int [Internet]. 2019;2019:1–7. Available from: https://doi.org/10.1155/2019/5917085
. [Last accessed on 2019 Oct 01].
Kochhar KP, Bijlani RL, Sachdeva U, Mahapatra SC, Padhy AK, Tandon RK. Gastro-intestinal effects of Indian spice mixture (Garam Masala). Trop Gastroenterol 1999;20:170-4.
Bisinotto FMB, Silveira LAM da, Rossi TC, Martins LB, Zago GP, Mendonça MAL. Comparative ultrasound study of gastric emptying between an isotonic solution and a nutritional supplement. Brazilian J Anesthesiol 2019;69:115-21.
Meyer R, Foong RXM, Thapar N, Kritas S, Shah N. Systematic review of the impact of feed protein type and degree of hydrolysis on gastric emptying in children. BMC Gastroenterol 2015;15:1-10.
Pouderoux P, Friedman N, Shirazi P, Ringelstein JG, Keshavarzian A. Effect of carbonated water on gastric emptying and intragastric meal distribution. Dig Dis Sci 1997;42:34-9.
Husband J, Husband P, Mallinson CN. Gastric emptying of starch meals in the newborn. Lancet 1970;296:290-2.
Pletsch EA, Hamaker BR. Brown rice compared to white rice slows gastric emptying in humans. Eur J Clin Nutr 2018;72:367-73.
Marciani L, Cox EF, Pritchard SE, Major G, Hoad CL, Mellows M, et al.
Additive effects of gastric volumes and macronutrient composition on the sensation of postprandial fullness in humans. Eur J Clin Nutr 2015;69:380-4.
Brun AC, Størdal K, Johannesdottir GB, Bentsen BS, Medhus AW. The effect of protein composition in liquid meals on gastric emptying rate in children with cerebral palsy. Clin Nutr 2012;31:108-12.
Kwiatek MA, Menne D, Steingoetter A, Goetze O, Forras-Kaufman Z, Kaufman E, et al
. Effect of meal volume and calorie load on postprandial gastric function and emptying: Studies under physiological conditions by combined fiber-optic pressure measurement and MRI. Am J Physiol-Gastrointest Liver Physiol 2009;297:894-901.
Kawasaki N, Suzuki Y, Urashima M, Nakayoshi T, Tsuboi K, Tanishima Y, et al.
Effect of gelatinization on gastric emptying and absorption. Hepatogastroenterology 2008;55:1843-5.
Velchik M, Reynolds J, Alavi A. The effect of meal composition on gastric emptying. J Nucl Med 1989;30:1106-10.
Montoya CA, Rutherfurd SM, Olson TD, Purba AS, Drummond LN, Boland MJ, et al.
Actinidin from kiwifruit (Actinidia deliciosa cv. Hayward) increases the digestion and rate of gastric emptying of meat proteins in the growing pig. J Nutr 2014;144:440-6.
Bornhorst GM, Roman MJ, Rutherfurd SM, Burri BJ, Moughan PJ, Singh RP. Gastric digestion of raw and roasted almonds in vivo
. J Food Sci 2013;78:H1807-13.
Fox M, Georgi G, Boehm G, Menne D, Fried M, Thumshirn M. Dietary protein precipitation properties have effects on gastric emptying in healthy volunteers. Clin Nutr 2004;23:641-6.
Lorenzo CDI, Williams CM, Valenzuela JE. Pectin delays gastric emptying. Nutr Rev 1989;47:268-70.
Perri F, Pastore M, Zicolella A, Annese V, Quitadamo M, Andriulli A. Gastric emptying of solids is delayed in celiac disease and normalizes after gluten withdrawal. Acta Pædiatr 2000;89:921-5.
Mackie AR, Bajka BH, Rigby NM, Wilde PJ, Alves-Pereira F, Mosleth EF, et al
. Oatmeal particle size alters glycemic index but not as a function of gastric emptying rate. Am J Physiol - Gastrointest Liver Physiol 2017;313:G239-46.
Jackson SJ, Leahy FE, Jebb SA, Prentice AM, Coward WA, Bluck LJC. Frequent feeding delays the gastric emptying of a subsequent meal. Appetite 2007;48:199-205.
Bornhorst GM, Chang LQ, Rutherfurd SM, Moughan PJ, Singh RP. Gastric emptying rate and chyme characteristics for cooked brown and white rice meals in vivo
. J Sci Food Agric 2013;93:2900-8.
Brady MC, Kinn S, Ness V, O'Rourke K, Randhawa N, Stuart P. Preoperative fasting for preventing perioperative complications in children. Cochrane Database Syst Rev 2009:CD005285. doi: 10.1002/14651858.CD005285.pub2.
Pedersen E, Lange K, Clifton P. Effect of fruit restriction on glycemic control in patients with type 2 diabetes: A randomized trial. Am J Clin Nutr 2016;104:1285-91.
Perrella SL, Hepworth AR, Gridneva Z, Simmer KN, Hartmann PE, Geddes DT. Gastric emptying of different meal volumes of identical composition in preterm infants: A time series analysis. Ped Research 2018;83:778-83.
Gopirajah R, Raichurkar KP, Wadhwa R, Anandharamakrishnan C. The glycemic response to fibre rich foods and their relationship with gastric emptying and motor functions: An MRI study. Food Funct 2016;7:3964-72.
Campolier M, Thondre SP, Clegg M, Shafat A, Mcintosh A, Lightowler H. Changes in PYY and gastric emptying across the phases of the menstrual cycle and the influence of the ovarian hormones. Appetite 2016;107:106-15.
Bell KJ, Smart CE, Steil GM, Brand-Miller JC, King B, Wolpert HA. Impact of fat, protein, and glycemic index on postprandial glucose control in type 1diabetes: Implications for intensive diabetes management in the continuous glucose monitoring era. Diabetes Care 2015;38:1008-15.
Syrkiewicz-Trepiak D, Jonderko K, Kasicka-Jonderko A. Effect of the osmolality of caloric and acaloric liquids on gastric myoelectrical activity in humans. Med Sci Monit 2010;16:252-9.
Najjar AM, Parsons PM, Duncan AM, Robinson LE, Yada RY, Graham TE. The acute impact of ingestion of breads of varying composition on blood glucose, insulin and incretins following first and second meals. Br J Nutr 2009;101:391-8.
Troncon LE, Iazigi N. Effect of test meal temperature on the gastric emptying of liquids. Braz J Med Biol Res 1988;21:57-60.
Sun WM, Houghton LA, Read NW, Grundy DG, Johnson AG. Effect of meal temperature on gastric emptying of liquids in man. Gut 1988;29:302-5.
Houghton L, Hickson F, Read N. Effect of food consistency on Gastric Emptying in Man. Gut 1987;28:1584-8.
Holt S, Reid J, Taylor T, Tothill P, Heading R. Gastric emptying of solids in man S. Gut 1982;23:292-6.
Mcgrady EM, Macdonald AG. Effect of the preoperative administration of water on gastric volume and ph. Br J Anaesth 1988;60:803-5.
Read MS, Vaughan RS. Allowing pre-operative patients to drink: Effects on patients ' safety and comfort of unlimited oral water until 2 hours before anaesthesia. Acta Anaesthesiol Scand 1991;35:591-5.
Ajuzieogu OV, Amucheazi AO, Nwagha UI, Ezike HA, Luka SK, Abam DS. Effect of routine preoperative fasting on residual gastric volume and acid in patients undergoing myomectomy. Niger J Clin Pract 2016;19:816-20.
] [Full text]
Yagci G, Can MF, Ozturk E, Dag B, Ozgurtas T, Cosar A, et al
. Effects of preoperative carbohydrate loading on glucose metabolism and gastric contents in patients undergoing moderate surgery: A randomized, controlled trial. Nutrition 2008;24:212-6.
Hutchinson A, Maltby JR, Reid CRG. Gastric fluid volume and pH in elective inpatients. Part I: Coffee or orange juice versus overnight fast. Can J Anaesth 1988;35:12-5.
Itou K, Fukuyama T, Suzuki N, Taniguchi H, Iwao Y, Hinenoya H, et al.
Safety and efficacy of oral rehydration therapy until 2 h before surgery: A multicenter randomized controlled trial. J Anesth 2012;26:20-7.
Phillips S, Hutchinson S, Davidson T. Preoperative drinking does not affect gastric contents. Br J Anaesth 1993;70:6-9.
Järvelä K, Maaranen P, Sisto T. Pre-operative oral carbohydrate treatment before coronary artery bypass surgery. Acta Anaesthesiol Scand 2008;52:793-7.
Agarwal A, Chari P, Singh H. Fluid deprivation before operation: The effect of a small drink. Anesthesia 1989;44:632-4.
Scarr M, Maltby JR. Volume and acidity of residual gastric fluid after oral fluid ingestion before elective ambulatory surgery. CMAJ 1989;141:1151-4.
Nygren J, Thorell A, Jacobsson H, Larsson S, Schnell PO, Hylén L, et al
. Preoperative gastric emptying: Effects of anxiety and oral carbohydrate administration. Ann Surg 1995;222:728-34.
Hausel J, Nygren J, Lagerkranser M, Hellström PM, Hammarqvist F, Almström C, et al
. A carbohydrate-rich drink reduces preoperative discomfort in elective surgery patients. Anesth Analg 2001;93:1344-50.
Breuer J, Griesbach M, Schickfus M Von, Mackh E, Hacker C, Elgeti U, et al
. Preoperative oral carbohydrate administration to ASA III – IV patients undergoing elective cardiac surgery. Anesth Analg 2006;103:1099-108.
Kaška M, Grosmanová T, Havel E, Hyšpler R. The impact and safety of preoperative oral or intravenous carbohydrate administration versus fasting in colorectal surgery – A randomized controlled trial. Wien Klin Wochenschr 2010;122:23-30.
Dock-nascimento DB. Safety of oral glutamine in the abbreviation of preoperative fasting; a double-blind, controlled, randomized clinical trial. Nutr Hosp 2011;1:86-90.
Yildiz H, Gunal SE, Yilmaz G, Yucel S. Oral carbohydrate supplementation reduces preoperative discomfort in laparoscopic cholecystectomy. J Investig Surg 2013;26:89-95.
Brianez LR, Caporossi C, de Moura YW, Dias LA, Leal RV, de Aguilar-Nascimento JE. Gastric residual volume by magnetic ressonance after intake of maltodextrin and glutamine: A randomized double-blind, crossover study. Arq Gastroenterol 2014;51:123-7.
Shevde K. Effects of clear liquids on gastric volume and pH in healthy volunteers. Anesth Analg 1991;72:528-31.
Siu L, Yee KH, Agarwal S, Monagle J, Canty DJ. The impact of preoperative oral ingestion of water on intraoperative gastric fluid volume for elective gastroscopy: A randomized controlled trial. J Anesth Clin Res 2014;5:5-7.
Gomes PC, Caporossi C, Aquilar-Nascimento JE, Silva AMC da, Araujo VMT de. Residual gastric volume evaluation with ultrasonography after ingestion of carbohydrate- or carbohydrate plus glutamine-enriched beverages: A randomized, crossover clinical trial with healthy volunteers. Arq Gastroenterol 2017;54:33-6.
Søreide E, Holst Larsen H, Reite K, Mikkelsen H, Soreide JA, Steen JA. Effects of giving 20-450ml of water with diazepam premedication 1-2 hours before general anaesthesia. Br J Anaesth 1993;71:503-6.
Husemeyer RP, Davenport HT, Rajasekaran T. Cimetidine as a single oral dose for prophylaxis against Mendelson's syndrome. Anaesthesia 1978;33:775-8.
Coombs DW, Hooper D, Colton T. Acid-aspiration prophylaxis by use of preoperative oral administration of cimetidine. Anesthesiology 1995;31:305-9.
Francis RN, Kwik RSH. Oral ranitidine for prophylaxis against Mendelson's syndrome. Anesth Analg 1982;61:130-2.
Salmenperå M, Korttila K, Kalima T. Reduction of the risk of acid pulmonary aspiration in anaesthetized patients after cimetidine prernedication. Acta Anaesthesiol Scand 1980;24:25-30.
Morison DH, Dunn GL, Fargas-babjak AM, Moudgil GC, Smedstad K, Woo J. A Double-Blind Comparison of Cimetidine and Aspiration Syndrome. Anesth Analg 1982;61:988–92.
Maile CJD, Francis RN. Pre-operative ranitidine: Effect of a single intravenous dose on pH and volume of gastric aspirate. Anaesthesia 1983;38:324-6.
Royer JE, Triplett RG. Effect of preoperative cimetidine and ranitidine on gastric secretion. J Oral Maxillofac Surg 1985;43:956-7.
Durrant JM, Strunin L. Comparative trial of the effect of ranitidine and cimetidine on gastric secretion in fasting patients at induction of anaesthesia. Can Anaesth Soc J 1982;29:446-51.
Aromaa U, Kalima TV. Ranitidine and prevention of pulmonary aspiration syndrome. Acta Anaesthesiol Scand 1986;30:10-2.
Kirkegaard P, Sørensen O, Kirkecaard P. Cimetidine in the prevention of acid aspiration during anesthesia. Acta Anaesthesiol Scand 1980;24:58-60.
Andrews AD, Brock-Utne JG, Downing JW. Protection against pulmonary acid aspiration with ranitidine: A new histamine H2 -receptor antagonist. Anaesthesia 1982;37:22-5.
Gonzalez ER, Kallar SK, Dunnavant BW. Single-dose intravenous H2blocker prophylaxis against aspiration pneumonitis: Assessment of drug concentration in gastric aspirate. J Am Assoc Nurse Anesth 1989;57:238-43.
Abe K, Shibata M, Demizu A, Hazano S, Sumikawa K, Enomoto H, et al
. Effect of oral and intramuscular famotidine on pH and volume of gastric contents. Anesth Analg 1989;68:541-4.
Escolano F, Castano J, Lopez R, Bisbe E, Alcon A. Effects of omeprazole, ranitidine, famotidine and lacebo on gastric secretion in patients ndergoing elective surgery. Br J Anaesth 1992;69:404-6.
O'Connor TA, Basak J, Parker S. The effect of three different ranitidine dosage regimens on reducing gastric acidity and volume in ambulatory surgical patients. Pharmacother J Hum Pharmacol Drug Ther 1995;15:170-5.
Cruickshank RH, Morrison DA, Bamber PA, Nimmo WS. Effect of I.V. omeprazole on the ph and volume of gastric contents before surgery. Br J Anaesth 1989;63:536-40.
Haskins DA, Jahr JS, Texidor M, Ramadhyani U. Single-dose oral omeprazole for reduction of gastric residual acidity in adults for outpatient surgery. Acta Anaesthesiol Scand 1992;36:513-5.
Hett DA, Scott RC, Risdall JE. Lansoprazole in the prophylaxis of acid aspiration during elective surgery. Br J Anaesth 1995;74:614-5.
Mehta S, Saroa R, Palta S, Mehta D. An evaluation of the comparative efficacy of preoperative oral omeprazole, lansoprazole and dexrabeprazole on gastric fluid pH and volume in patients undergoing elective surgery under general anaesthesia. Northern Journal of ISA 2016;1:54-57.
Memiş D, Turan A, Karamanlioglu B, Saral P, Türe M, Pamukçu Z. The effect of intravenous pantoprazole and ranitidine for improving preoperative gastric fluid properties in adults undergoing elective surgery. Anesth Analg 2003;97:1360-3.
Gouda BB, Lydon AM, Badhe A, Shorten GD. A comparison of the effects of ranitidine and omeprazole on volume and pH of gastric contents in elective surgical patients. Eur J Anaesthesiol 2004;21:260-4.
Hendolin H, Suojaranta-Ylinen R, Alhava E. Effect of single-dose omeprazole and ranitidine on gastric juice acidity and volume in patients undergoing laparotomy. Acta Anaesthesiol Scand 1993;37:484-7.
Goel C, Anand LK, Gombar KK. Comparative evaluation of single dose intravenous pantoprazole and ranitidine on gastric pH and volume: A double blind study. J Anaesthesiol Clin Pharmacol 2006;22:145-9. [Full text]
Nishina K, Mikawa K, Maekawa N, Takao Y, Shiga M, Obara H. A comparison of lansoprazole, omeprazole, and ranitidine for reducing preoperative gastric secretion in adult patients undergoing elective surgery. Anesth Analg 1996;82:832-6.
Nishina K, Mikawa K, Takao Y, Shiga M, Maekawa N, Obara H. A comparison of rabeprazole, lansoprazole, and ranitidine for improving preoperative gastric fluid property in adults undergoing elective surgery. Anesth Analg 2000;90:717-21.
Levack ID, Bowie RA, Braid DP, Asbury AJ, Marshall RL, Slawson KB, et al
. Comparison of the effect of two dose schedules of oral omeprazole with oral ranitidine on gastric aspirate pH and volume in patients undergoing elective surgery. Br J Anaesth 1996;76:567-9.
Dattatraya G, Ullhas M. A comparative efficacy of conventional H 2 receptor blocker ranitidine and newer proton pump inhibitors omeprazole, pantoprazole and esomeprazole for improvement of gastric fluid property in adults undergoing elective surgery. IOSR J Dent Med Sci Ver III 2015;14:2279-861. Available from: www.iosrjournals.org. [Last accessed on 2019 Oct 01].
Puig I, Calzado S, Suárez D, Sánchez-Delgado J, López S, Calvet X. Meta-analysis: Comparative efficacy of H2-receptor antagonists and proton pump inhibitors for reducing aspiration risk during anaesthesia depending on the administration route and schedule. Pharmacol Res 2012;65:480-90. Available from: http://dx.doi.org/10.1016/j.phrs. 2012.01.005
. [Last accessed on 2019 Oct 01].
Clark K, Lam LT, Gibson S, Currow D. The effect of ranitidine versus proton pump inhibitors on gastric secretions: A meta-analysis of randomised control trials. Anaesthesia 2009;64:652-7.
Pandit SK, Kothary SP, Pandit UA, Mirakhur RK. Premedication with cimetidine and metoclopramide: Effect on the risk factors of acid aspiration. Anaesthesia 1986;41:486-92.
Solanki DR, Suresh M, Ethridge HC. The effects of intravenous cimetidine and metoclopramide on gastric volume and pH. Anesth Analg 1984;63:599-602.
Hong JY. Effects of metaclopramide and ranitidine on preoperative gastric contents in day-case surgery. Yonsei Med J 2006;47:315-8.
Manchikanti L, Colliver JA, Marrero TC, Roush JR. Ranitidine and metoclopramide for prophylaxis of aspiration pneumonitis in elective surgery. Anesth Analg 1984;63:903-10.
Manchikanti L, Marrero TC, Roush JR. Pre anesthetic cimetidine and metoclopramide for acid aspiration prophylaxis in elective surgery. Anesthesiology 1995;31:305-9.
Dimich I, Katende R, Pal Singh P, Mikula S, Sonnenklar N. The effects of intravenous cimetidine and metoclopranide on gastric pH and volume in outpatients. J Clin Anesth 1991;3:40-4.
Gombar S, Kiran S, Gupta M, Gombar K, Chhabra B. Preanaesthetic oral ranitidine, omeprazole and metoclopramide for modifying gastric fluid volume and pH. Can J Anaesth 1994;41:879-80.
Schmidt JF, Sghierup L, Banning A-M. The effect of sodium citrate on the pH and the amount of gastric contents before general anaesthesia. Acta Anaesthesiol Scand 1984;28:263-5.
Maltby JR, Elliott RH, Warnell I, Fairbrass M, Sutherland LR, Shaffer EA. Gastric fluid volume and pH in elective surgical patients: Triple prophylaxis is not superior to ranitidine alone. Can J Anaesth 1990;37:650-5.
Foulkes E, Jenkins LC. A comparative evaluation of cimetidine and sodium citrate to decrease gastric acidity: Effectiveness at the time of induction of anaesthesia. Can Anaesth Soc J 1981;28:29-32.
Chan YK. A comparison of sodium citrate and sodium citrate/ranitidine combination for acid aspiration prophylaxis. Med J Malaysia 1992;47:27-30.
Suojaranta-Ylinen R, Hendolin H, Alhava E, Kontra K. The effect of prophylactic use of famotidine, ranitidine, and sodium citrate in upper abdominal surgery. Agents Actions 1990;30:297-9.
Manchikanti L, Grow JB, Colliver JA. Bicitra® (sodium citrate) and metoclopramide in outpatient anesthesia for prophylaxis against aspiration pneumonitis. Anesthesiology 1985;63:378-84.
Stoelting RK. Responses to atropine, glycopyrrolate, and riopan of gastric fluid pH and volume in adult patients. Anesthesiology 1978;48:367-9.
Stoelting RK. Gastric fluid volume and pH after fentanyl, enflurane, or halothane-nitrous oxide anesthesia with or without atropine or glycopyrrolate. Anesth Analg 1980;59:287-90.
Manchikanti L, Roush JR. Effect of preanesthetic glycopyrrolate and cimetidine on gastric fluid pH and volume in outpatients. Anesth Analg 1984;63:40-6.
Bhattacharyya T, Sarbapalli D, Pal R, Sarkar U, Kar S, Kundu KK, et al
. Evaluating ranitidine, pantoprazole and placebo on gastric pH in elective surgery. Saudi J Anaesth 2011;5:67-72.
Viegas OJ, Ravindran RS, Shumacker CA. Gastric fluid pH in patients receiving sodium citrate. Anesth Analg 1981;60:521-3.
Bickel A, Shtamler B, Mizrahi S. Early oral feeding following removal of nasogastric tube in gastrointestinal operations: A randomized prospective study. Arch Surg 1992;127:287-9.
Andersen HK, Lewis SJ, Thomas S. Early enteral nutrition within 24h of colorectal surgery versus later commence-ment of feeding for postoperative complications. Cochrane Database Syst Rev 2006, Issue 4. Art. No.: CD004080. doi: 10.1002/14651858.CD004080.pub2.
Herbert G, Perry R, Andersen HK, Atkinson C, Penfold C, Lewis SJ, et al
. Early enteral nutrition within 24 hoursof lower gastrointestinal surgery versus later commencement for length of hospital stay and postoperative complications. Cochrane Database Syst Rev 2019, Issue 7. Art. No.: CD004080. doi: 10.1002/14651858.CD004080.pub4.
Bouvet L, Loubradou E, Desgranges FP, Chassard D. Effect of gum chewing on gastric volume and emptying: A prospective randomized crossover study. Br J Anaesth 2017;119:928-33.
Ouanes JPP, Bicket MC, Togioka B, Tomas VG, Wu CL, Murphy JD. The role of perioperative chewing gum on gastric fluid volume and gastric pH: A meta-analysis. J Clin Anesth 2015;27:146-52.
Best GWJ, Fanning SB, Robertson IK, Blackford D, Mitchell BL. Assessing the effect of sugar-free chewing gum use on the residual gastric volume of patients fasting for gastroscopy: A randomised controlled trial. Anaesth Intensive Care 2019;47:541-7.
Goudra BG, Singh PM, Carlin A, Manjunath AK, Reihmer J, Gouda GB, et al.
Effect of gum chewing on the volume and pH of gastric contents: A prospective randomized study. Dig Dis Sci 2015;60:979-83.
Valencia JA, Cubillos J, Romero D, Amaya W, Moreno J, Ferrer L, et al
. Chewing gum for 1 h does not change gastric volume in healthy fasting subjects. A prospective observational study. J Clin Anesth 2019;56:100-5.
Shanmugam S, Goulding G, Gibbs NM, Taraporewalla K, Culwick M. Chewing gum in the preoperative fasting period: An analysis of de-identified incidents reported to webAIRS. Anaesth Intensive Care 2016;44:282-5.
Short V, Herbert G, Perry R, Atkinson C, Ness AR, Penfold C, et al
. Chewing gum for postoperative recovery of gastrointestinal function. Cochrane Database Syst Rev 2015, Issue 2. Art. No.: CD006506. doi: 10.1002/14651858.CD006506.pub3.
Wen ZJ, Wang WT, Mei B Bin, Wu C, Shen MF. Gum chewing for promoting intestinal function recovery after colorectal cancer surgery: A meta-analysis. World Chinese J Dig 2017;25:147-58.
Su'a BU, Pollock TT, Lemanu DP, MacCormick AD, Connolly AB, Hill AG. Chewing gum and postoperative ileus in adults: A systematic literature review and meta-analysis. Int J Surg 2015;14:49-55.
Kumar A, Kumari R, Kumar S, Raj P. Effect of chewing gum on bowel motility in post operative patients following abdominal surgery: A clinical outcome based study. Int Surg J 2018;5:2808.
Kalyanwat AS, Jakhar M, Jain S. Postoperative ileus: A study on the role of chewing gum to reduce its duration. Saudi Surg J 2018;6:85-8. [Full text]
Pilevarzadeh M. Effect of gum chewing in the reduction of paralytic ileus following cholecystectomy. Biomed Pharmacol J 2016;9:405-9.
Franke A, Nakchbandi IA, Schneider A, Harder H, Singer MV. The effect of ethanol and alcoholic beverages on gastric emptying of solid meals in humans. Alcohol Alcohol 2005;40:187-93.
Mushambi MC, Bailey SM, Trotter TN, Chadd GD, Rowbotham DJ. Effect of alcohol on gastric emptying in volunteers. Br J Anaesth 1993;71:674-6.
Kaufman SE, Kaye MD. Effect of ethanol upon gastric emptying. Gut 1979;20:688-92.
Barboriak J., Meade RC. Effect of alcohol on gastric emptying in man. Am J Clin Nutr 1970;22:1151-3.
Scott AM, Kellow JE, Shuter B, Nolan JM, Hoschl R, Jones MP. Effects of cigarette smoking on solid and liquid intragastric distribution and gastric emptying. Gastroenterology 1993;104:410-6.
Miller G, Palmer KR, Smith B, Ferrington C, Merrick MV. Smoking delays gastric emptying of solids. Gut 1989;30:50-3.
Wong PWK, Kadakia SC, McBiles M. Acute effect of nicotine patch on gastric emptying of liquid and solid contents in healthy subjects. Dig Dis Sci 1999;44:2165-71.
Lazaar S, Boselli E, Chassard D, Allaouchiche B, Bouvet L. Effect of acute cigarette smoking on gastric contents in regular smoker volunteers. A prospective randomized cross-over study. Br J Anaesth 2015;115:590-4.
Olsson GL, Hallen B, Hambraeus-Jonzon K. Aspiration during anaesthesia: A computer-aided study of 185 358 anaesthetics. Acta Anaesthesiol Scand 1986;30:84-92.
Soreide E, Bjornestad E, Steen PA. An audit of perioperative aspiration pneumonitis in gynaecological and obstetric patients. Acta Anaesthesiol Scand 1996;40:14-9.
Ezri T, Szmuk P, Stein A, Konichezky S, Hagai T, Geva D. Peripartum general anaesthesia without tracheal intubation: Incidence of aspiration pneumonia. Anaesthesia 2000;55:421-6.
Dean G, Jacobs AR, Goldstein RC, Gevirtz CM, Paul ME. The safety of deep sedation without intubation for abortion in the outpatient setting. J Clin Anesth 2011;23:437-42.
Aksel S, Lang L, Steinauer JE, Drey EA, Lederle L, Sokoloff A, et al.
Safety of deep sedation without intubation for second-trimester dilation and evacuation. Obstet Gynecol 2018;132:171-8.
Dureja J, Goyal P, Thakur A, Chhabra B. Perioperative pulmonary aspiration in obstetric and gynaecological patients - Two case reports. Indian J Anaesth 2003;47:122-4. [Full text]
Davison JS, Davison MC, Hay M. Gastric emptying time in Late pregnancy and labour. J Obstet Gynaecol Br Commonw 1970;77:37-41.
Simpson KH, Stakes AF, Miller M. Pregnancy delays paracetamol absorption and gastric emptying in patients undergoing surgery. Br J Anaesth 1988;60:24-7.
Macfie AG, Magides AD, Richmond MN, Reilly CS. Gastric emptying in pregnancy. Br J Anaesth 1991;67:54-7.
Sandhar BK, Elliott RH, Windram I, Rowbotham DJ. Peripartum changes in gastric emptying. Anaesthesia 1992;47:196-8.
Whitehead EM, Smith M, Dean Y, Sullivan GO. An evaluation of gastric emptying times in pregnancy and the puerperium. Anaesthesia 1993;48:53-7.
Wald A, Van Theil DH, Hoechstetter L, Gavaler JS, Egler KM, Verm R et al
. Effect of Pregnancy on Gastrointestinal Transit. Dig Dis Sci 1982;27:15-8.
Chiloiro M, Darconza G, Piccioli E, De Carne M, Clemente C, Riezzo G. Gastric emptying and orocecal transit time in pregnancy. J Gastroenterol 2001;36:538-43.
Wong CA, Loffredi M, Ganchiff JN, Zhao J, Wang Z, Avram MJ. Gastric emptying of water in term pregnancy. Anesthesiology 2002;96:1395-400.
Wong CA, McCarthy RJ, Fitzgerald PC, Raikoff K, Avram MJ. Gastric emptying of water in obese pregnant women at term. Anesth Analg 2007;105:751-5.
Hong JY, Jung WP, Jong IO. Comparison of preoperative gastric contents and serum gastrin concentrations in pregnant and nonpregnant women. J Clin Anesth 2005;17:451-5.
Qvist N, Storm K. Cimethidine Pre-Anesthetic: A prophylactic method against Mendelson's syndrome in cesarean section. Acta Obstet Gynecol Scand 1983;62:157-9.
Dewan DM, Floyd HM, Thistlewood JM, Bogard TD, Spielman FJ. Sodium citrate pretreatment in elective cesarean section patients. Anesth Analg 1985;64:34-7.
O'Sullivan G, Sear JW, Bullingham RES, Carrie LES. The effect of magnesium trisilicate mixture, metoclopramide and ranitidine on gastric pH, volume and serum gastrin. Anaesthesia 1985;40:246-53.
Abboud TK, Curtis J, Earl S, Henriksen EH, Hughes SC, Levinson G, et al
. Efficacy of clear antacid prophylaxis in obstetrics. Acta Anaesthesiol Scand 1984;28:301-4.
Colman RD, Loughnan FBA, Cohen DG, Cattermole R. Use of I.M. ranitidine for the prophylaxis of aspiration pneumonitis in obstetrics. Br J Anaesth 1988;61:720-9.
Ormezzano X, Francois TP, Viaud JY, Bukowski JG, Bourgeonneau MC, Cottron D, et al
. Aspiration pneumonitis prophylaxis in obstetric anaesthesia: Comparison of effervescent cimetidine-sodium citrate mixture and sodium citrate. Br J Anaesth 1990;64:503-6.
Lim SK, Elegbe EO. The use of single dose of sodium citrate as a prophylaxis against acid aspiration syndrome in obstetric patients undergoing caesarian section. Med J Malaysia 1991;46:349-55.
Rout CC, Rocke DA, Gouws E. Intravenous ranitidine reduces the risk of acid aspiration of gastric contents at emergency cesarean section. Anesth Analg 1993;76:156-61.
Stuart JC. Acid aspiration prophylaxis for emergency Caesarean section. Anaesthesia 1996;51:415-21.
Yau G, Kan AF, Gin T, Oh TE. A comparison of omeprazole and ranitidine for prophylaxis against aspiration pneumonitis in emergency Caesarean section. Anaesthesia 1992;47:101-4.
Orr DA, Bill KM, Gillon KRW, Wilson CM, Fogarty DJ, Moore J. Effects of omeprazole, with and without metoclopramide, in elective obstetric anaesthesia. Anaesthesia 1993;48:114-9.
Tripathi A, Somwanshi M, Singh B, Bajaj P. A comparison of intravenous ranitidine and omeprazole on gastric volume and pH in women undergoing emergency Caesarean section. Can J Anaesth 1995;42:797-800.
Gyte GM, Richens Y. Routine prophylactic drugs in normal labour for reducing gastric aspiration and its effects. Cochrane Database Syst Rev 2006;2006:CD005298. Published 2006 Jul 19. doi: 10.1002/14651858.CD005298.pub2.
Paranjothy S, Griffiths JD, Broughton HK, Gyte GML, Brown HC, Thomas J. Interventions at caesarean section for reducing the risk of aspiration pneumonitis. Int J Obstet Anesth 2011;20:142-8.
Burgess RW, Crowhurst JA. Acid aspiration prophylaxis in Australian obstetric hospitals. A survey. Anaesth Intensive Care 1989;17:492-5.
Tordoff SG, Sweeney BP. Acid aspiration prophylaxis in 288 obstetric anaesthetic departments in the United Kingdom. Anaesthesia 1990;45:776-80.
Greiff JMC, Tordoff SG, Griffiths R, May AE. Acid aspiration prophylaxis in 202 obstetric anaesthetic units in the UK. Int J Obstet Anesth 1994;3:137-42.
Adupa D, Wandabwa J, Kiondo P. A randomised controlled trial of early initiation of oral feeding after caesarean delivery in Mulago Hospital. East Afr Med J 2003;80:345-50.
Mehta S, Gupta S, Goel N. Postoperative oral feeding after cesarean section—Early versus late initiation: A prospective randomized trial Sumita. J Gynecol Surg 2010;26:247-50.
Saad AF, Saoud F, Diken ZM, Hegde S, Kuhlmann MJ, Wen TS, et al
. Early versus late feeding after cesarean delivery: A randomized controlled trial. Am J Perinatol 2016;33:415-9.
Orji EO, Olabode TO, Kuti O, Ogunniyi SO. A randomised controlled trial of early initiation of oral feeding after cesarean section. J Matern Neonatal Med 2009;22:65-71.
Izbizky GH, Minig L, Sebastiani MA, Otaño L. The effect of early versus delayed postcaesarean feeding on women's satisfaction: A randomised controlled trial. BJOG An Int J Obstet Gynaecol 2008;115:332-8.
Al-Takroni AMB, Parvathi CK, Mendis KBL, Hassan S, Qunaibi AM. Early oral intake after caesarean section performed under general anaesthesia. J Obstet Gynaecol 1999;19:34-7.
Jalilian N, Ghadami MR. Randomized clinical trial comparing postoperative outcomes of early versus late oral feeding after cesarean section. J Obstet Gynaecol Res 2014;40:1649-52.
Kathpalia SK. Early maternal feeding versus traditional delayed feeding after cesarean section: A pilot study. J Obstet Gynecol India 2017;67:178-82.
Mawson AL, Bumrungphuet S, Manonai J. A randomized controlled trial comparing early versus late oral feeding after cesarean section under regional anesthesia. Int J Womens Health 2019;11:519-25.
Teoh WHL, Shah MK, Mah CL. A randomised controlled trial on beneficial effects of early feeding post-Caesarean delivery under regional anaesthesia. Singapore Med J 2007;48:152-7.
Ogbadua AO, Agida TE, Akaba GO, Akitoye OA, Ekele BA. Early versus delayed oral feeding after uncomplicated cesarean section under spinal anesthesia: A randomized controlled trial Adamu. Niger J Surg 2018;24:6-11.
] [Full text]
Tan PC, Alzergany MM, Adlan AS, Noor Azmi MA, Omar SZ. Immediate compared with on-demand maternal full feeding after planned caesarean delivery: A randomised trial. BJOG An Int J Obstet Gynaecol 2017;124:123-31.
Chantarasorn V, Tannirandorn Y. A comparative study of early postoperative feeding versus conventional feeding for patients undergoing cesarean section; A Randomized controlled trial. J Med Assoc Thail 2006;89(Suppl 4):S11-6.
Patolia DS, Hilliard RLM, Toy EC, Baker B. Early feeding after cesarean: Randomized trial. Obstet Gynecol 2001;98:113-6.
Göçmen A, Göçmen M, Saraoǧlu M. Early post-operative feeding after caesarean delivery. J Int Med Res 2002;30:506-11.
Dar LR, Rasul S SS. Early versus delayed oral feeding for patients after cesarean. Int J Gynecol Obstet 2015;128:100-5.
Huang H, Wang H, He M. Early oral feeding compared with delayed oral feeding after cesarean section: A meta-analysis. J Matern Fetal Neonatal Med 2016;29:423-9.
Hsu YY, Hung HY, Chang SC, Chang YJ. Early oral intake and gastrointestinal function after cesarean delivery: A systematic review and meta-analysis. Obstet Gynecol 2013;121:1327-34.
Guo J, Long S, Li H, Luo J, Han D, He T. Early versus delayed oral feeding for patients after cesarean. Int J Gynecol Obstet 2015;128:100-5.
Mangesi L, Hofmeyr GJ. Early compared with delayed oral fluids and food after caesarean section. Cochrane Database Syst Rev 2002;CD003516. doi: 10.1002/14651858.CD003516.
Gin T, Cho AMW, Lew JKL, Lau GSN, Yuen PM, Critchley JAJH, et al
. Gastric emptying in the postpartum period. Anaesth Intensive Care 1991;19:521-4.
Lam KK, So HY, Gin T. Gastric pH and volume after oral fluids in the postpartum patient. Can J Anaesth 1993;40:218-21.
Ahmed MR, Sayed Ahmed WA, Khamess RE, Youwakim MS, El-Nahas KM. Efficacy of three different regimens in recovery of bowel function following elective cesarean section: A randomized trial. J Perinat Med 2018;46:786-90.
Abd-El-Maeboud KH, Ibrahim MI, Shalaby DA, Fikry MF. Gum chewing stimulates early return of bowel motility after caesarean section. BJOG An Int J Obstet Gynaecol 2009;116:1334-9.
Kafali H, Duvan CI, Gözdemir E, Simavli S, Onaran Y, Keskin E. Influence of gum chewing on postoperative bowel activity after cesarean section. Gynecol Obstet Invest 2010;69:84-7.
Ledari FM, Barat S, Delavar MA. Chewing gums has stimulatory eff ects on bowel function in patients undergoing cesarean section: A randomized controlled trial. Bosn J Basic Med Sci 2012;12:265-8.
Mohsenzadeh Ledari F, Barat S, Delavar MA, Banihosini SZ, Khafri S. Chewing sugar-free gum reduces ileus after cesarean section in nulliparous women: A randomized clinical trial. Iran Red Crescent Med J 2013;15:330-4.
Shang H, Yang Y, Tong X, Zhang L, Fang A, Hong L. Gum chewing slightly enhances early recovery from postoperative Ileus after cesarean section: Results of a prospective, randomized, controlled trial. Am J Perinatol 2010;27:387-91.
Rashad WAE-H, Yousef SA AL. Effect of sugarless gum chewing on intestinal movement after cesarean section. Life Sci J 2013;10:3257-61.
Jakkaew B, Charoenkwan K. Effects of gum chewing on recovery of bowel function following cesarean section: A randomized controlled trial. Arch Gynecol Obstet 2013;288:255-60.
Bonner JJ, Vajjah P, Abduljalil K, Jamei M, Rostami-Hodjegan A, Tucker GT, et al.
Does age affect gastric emptying time? A model-based meta-analysis of data from premature neonates through to adults. Biopharm Drug Dispos 2015;36:245-57.
Cote CJ, Goudsouzian NG, Liu LMP, Dedrick DF, Szyfelbein SK. Assessment of risk factors related to the acid aspiration syndrome in pediatric patients – gastric pH and residual volume. Anesthesiology 1982;56:70-2.
Manchikanti L, Colliver JA, Marrero TC, Roush JR. Assessment of age-related acid aspiration risk factors in pediatric, adult, and geriatric patients. Anesth Analg 1985;64:11-7.
Osatakul S, Sriplung H, Puetpaiboon A, Junjana C, Chamnongpakdi S. Prevalence and natural course of gastroesophageal reflux symptoms: A 1- year cohort study in Thai infants. J Pediatr Gastroenterol Nutr 2002;34:63-7.
Cook-Sather SD, Gallagher PR, Kruge LE, Beus JM, Ciampa BP, Welch KC, et al
. Overweight/obesity and gastric fluid characteristics in pediatric day care surgery: Implications for fasting guidelines and pulmonary aspiration risk. Anesth Analg 2009;109:727-36.
Borland LM, Sereika SM, Woelfel SK, Saitz EW, Carrillo PA, Lupin JL, et al
. Pulmonary aspiration in pediatric patients during general anesthesia: Incidence and outcome. J Clin Anesth 1998;10:95-102.
Warner MA, Warner ME, Warner DO, Warner LO, Warner JE. Perioperative pulmonary aspiration in infants and children. Anesthesiology 1999; 90:66-71.
Andersson H, Zare'n B, Frykholm P. Low incidence of pulmonary aspiration in children allowed intake of clear fluids until called to the operating suite. Pediatr Anesth 2015;25:770-7.
Habre W, Disma N, Virag K, Becke K, Hansen TG, Johr M, et al
. Incidence of severe critical events in paediatric anaesthesia (APRICOT): A prospective multicentre observational study in 261 hospitals in Europe. Lancet Respir Med 2017. doi: 10.1016/S2213-2600(17)30116-9.
Eisler L, Huang G, Lee KM, Busse JA, Sun M, Lin AY, et al
. Identification of perioperative pulmonary aspiration in children using quality assurance and hospital administrative billing data. Paediatr Anaesth 2018;28:218-25.
Beck CE, Rudolp D, Becke-Jakob K, Schindler E, Etspüler A, Trapp A, et al
. Real fasting times and incidence of pulmonary aspiration in children: Results of a German prospective multicenter observational study. Paediatr Anaesth 2019;29:1040-5.
Tan Z, Lee SY. Pulmonary aspiration under GA: A 13-year audit in a tertiary pediatric unit. Paediatr Anaesth 2016;26:547-52.
Walker RWM. Pulmonary aspiration in pediatric anesthetic practice in the UK: A prospective survey of specialist pediatric centers over a one-year period. Pediatr Anesth 2013;23:702-11.
Kluger MT, Short TG. Aspiration during anaesthesia: A review of 133 cases from the Australian Anaesthetic Incident Monitoring Study (AIMS). Anaesthesia 1999;54:19-26.
Yoon SI, Kang J. Aspiration pneumonia in a pediatric patient under general anesthesia despite adequate preoperative fasting. Korean J Crit Care Med 2015;30:313-5.
Du T, Hill L, Ding L, Towbin AJ, Dejonckheere M, Bennett P, et al.
Gastric emptying for liquids of different compositions in children. Br J Anaesth 2017;119:948-55.
Ewer AK, Durbin GM, Morgan MEI, Booth IW. Gastric emptying in preterm infants. Arch Dis Child 1994;71:F24-7.
Schmitz A, Kellenberger CJ, Liamlahi R, Studhalter M, Weiss M. Gastric emptying after overnight fasting and clear fluid intake: A prospective investigation using serial magnetic resonance imaging in healthy children. Br J Anaesth 2011;107:425-9.
Knatten KC, Avitsland TL, Medhus AW, Fjeld JG, Pripp AH, Emblem R, et al
. Gastric emptying in children with gastroesophageal reflux and in healthy children. J Ped Surg 2013;48:1856-61.
Parashar A, Pawar S, Ghorpade M, Shetye S, Tilve G. Liquid gastric emptying time 1/2 in infants: establishing reference range and it's co-relation with presence of gastro-esophageal reflux. Int J Res Med Sci 2016;4:4788-92.
Malik R, Srivastava A, Gambhir S, Yachha SK, Siddegowda M, Ponnusamy M, et al
. Assessment of gastric emptying in children: Establishment of control values utilizing a standardized vegetarian meal. J Gastroenterol Hepatol 2016;31:319-25.
Perrella SL, Hepworth AR, Simmer KN, Geddes DT. Influences of breast milk composition on gastric emptying in preterm infants. J Pediatr Gastroenterol Nutr 2015;60:264-71.
Sethi AK, Chatterji C, Bhargava SK, Narang P, Tyagi A. Safe pre-operative fasting times after milk or clear fluid in children. A preliminary study using real-time ultrasound. Anaesthesia 1999;54:51-9.
Schmitz A, Kellenberger CJ, Lochbuehler N, Fruehauf M, Klaghofer R, Fruehauf H, et al.
Effect of different quantities of a sugared clear fluid on gastric emptying and residual volume in children: A crossover study using magnetic resonance imaging. Br J Anaesth 2012;108:644-7.
Yigit S, Akgoz A, Memisoglu A, Akata D, Ziegler EE. Breast milk fortification: Effect on gastric emptying. J Matern Fetal Neonatal Med 2008;21:843-6.
Singh SJ, Gibbons NJ, Blackshaw PE, Vincent M, Walker J, Perkins AC. Gastric emptying of solids in normal children-A preliminary report. J Pediatr Surg 2006;41:413-7.
Sümpelmann AE, Sümpelmann R, Lorenz M, Eberwien I, Dennhardt N, Boethig D, et al
. Ultrasound assessment of gastric emptying after breakfast in healthy preschool children. Pediatr Anesth 2017;27:816-20.
Schmidt AR, Buehler P, Seglias L, Stark T, Brotschi B, Renner T, et al
. Gastric pH and residual volume after 1 vs 2 h fasting time for clear fluids in children. Br J Anaesth 2015;114:477-82.
Schmidt AR, Buehler KP, Both Ch, Wiener R, Klaghofer R, Hersberger M, et al
. Liberal fluid fasting: Impact on gastric pH and residual volume in healthy children undergoing general anaesthesia for elective surgery. Br J Anaesth 2018;121:647-55.
Schreiner MS, Triebwasseer A, Keon TP. Ingestion of liquids compared with preoperative fasting in pediatric outpatients. Anesthesiology 1990;72:593-7.
Nicolson SC, Dorsey AT, Schreiner MS. Shortened preanesthetic fasting interval in pediatric cardiac surgical patients. Anesth Analg 1992;74:694-7.
Litman RS, Wu CL, Quinlivan JK. Gastric volume and pH in infants fed clear liquids and breast milk prior to surgery. Anesth Analg 1994;79:482-5.
Maekawa N, Mikawa K, Yaku H, Nishina K, Obara H. Effects of 2-, 4- and 12-hour fasting intervals on preoperative gastric fluid pH and volume, and plasma glucose and lipid homeostasis in children. Acta Anaesth Scand 1993;37:783-7.
Cook-Sather SD, Harris KA, Rosetta C, Gallagher PR, Schreiner MS. A liberalized fasting guideline for formula-fed infants does not increase average gastric fluid volume before elective surgery. Anesth Analg 2003;96:965-9.
Tudor-Drobjewski BA, Marhofer P, Kimberger O, Huber WD, Roth G, Triffterer L. Randomised controlled trial comparing preoperative carbohydrate loading with standard fasting in paediatric anaesthesia. Br J Anaesth 2018;121:656-61
Splinter WM, Schaefer D. Unlimited clear fluid ingestion two hours before surgery in children does not affect volume or pH of stomach contents. Anaesth Intens Care 1990;18:522-6.
Schmitz A, Kellenberger CJ, Liamlahi R, Fruehauf M, Klaghofer R, Weiss M. Residual gastric contents volume does not differ following 4 or 6 h fasting after a light breakfast – A magnetic resonance imaging investigation in healthy non-anaesthetised school-age children. Acta Anaesthesiol Scand 2012;56:589-94.
Schmitz A, Kellenberger CJ, Neuhaus D, Schroeter E, Deanovic D, Prufer F, et al
. Fasting times and gastric contents volume in children undergoing deep propofol sedatilon – An assessment using magnetic resonance imaging. Ped Anesth 2011;21:685-90.
Gounaris A, Costalos C, Varchalama E, Kokori F, Grivea IN, Konstantinidi K. Gastric emptying of preterm neonates receiving domperidone. Neonatology 2010;97:56-10
Sandhar BK, Goresky GV, Maltby JR, Shaffer EA: Effect of oral liquids and ranitidine on gastric fluid volume and pH in children undergoing outpatient surgery. Anesthesiology 1989;71:327-30.
Mathai SS, Bawa KS, Bhandari A. Effect of erythromycin on gastric emptying time of low birth weight babies. Med J Armed Forces India 2007;63:226-8.
Goresky GV, Finley GA, Bissonnette B, Shaffer EA. Efficacy, duration and absorption of a paediatric oral liquid preparation of ranitidine hydrochloride. Can J Anesth 1992;39:791-8.
Wittgrove C, Birisci E, Kantor J, Dalabih A. Gastric volume and its relationship to underlying pathology or acid-suppressing medication. Anesth Essays Res 2017;11:881-5.
] [Full text]
Beach ML, Cohen DM, Gallagher SM, Cravero JP. Major adverse events and relationship to nil per os status in pediatric sedation/anesthesia outside the operating room: A report of the Pediatric Sedation Research Consortium. Anesthesiology 2016;124:80-8.
Agrawal D, Manzi SF, Gupta R, Krauss B. Preprocedural fasting state and adverse events in children undergoing procedural sedation and analgesia in a pediatric emergency department. Ann Emerg Med 2003;42:636-46.
Bhatt M, Johnson DW, Taljaard M, Chan J, Barrowman N, Farion KJ, et al
. Association of preprocedural fasting with outcomes of emergency department sedation in children. JAMA Pediatr 2018;172:678-85.
Babl FE, Puspitadewi A, Barnett P, Oakley E, Spicer M. Preprocedural fasting state and adverse events in children receiving nitrous oxide for procedural sedation and analgesia. Pediatr Emerg Care 2005;21:736-43.
Clark M, Birisci E, Anderson J, Anliker C, Bryant M, Downs C, et al.
The risk of shorter fasting time for pediatric deep sedation. Anesth Essays Res 2016;10:607.
] [Full text]
Bhatt M, Currie GR, Auld MC, Johnson DW. Current practice and tolerance for risk in performing procedural sedation and analgesia on children who have not met fasting guidelines: A Canadian survey using a stated preference discrete choice experiment. Acad Emerg Med 2010;17:1207-15.
Chauvin C, Schalber-Geyer AS, Lefebvre F, Bopp C, Carrenard G, Marcoux L, et al
. Early postoperative oral fluid intake in paediatric day case surgery influences the need for opioids and postoperative vomiting: A controlled randomized trial. Br J Anaesth 2017;118:407-14.
Brunet-Wood K, Simons M, Evasiuk A, Mazurak V, Dicken B, Ridley D, et al.
Surgical fasting guidelines in children: Are we putting them into practice? J Pediatr Surg 2016;51:1298-302.
Arun BG, Korula G. Preoperative fasting in children: An audit and its implications in a tertiary care hospital. J Anaesthesiol Clin Pharmacol 2013;29:88-91.
] [Full text]
Alvi NI. A prospective, cross-sectional survey of pre-operative fasting of pediatric surgical patients in a university hospital. Anaesth Pain and Intensive Care 2016;20:171-5.
Buller Y, Sims C. Prolonged fasting of children before anaesthesia is common in private practice. Anaesth Intensive Care 2016;44:107e10.
Engelhardt T, Wilson G, Horne L, Weiss M, Schmitz A. Are you hungry? Are you thirsty?--fasting times in elective outpatient pediatric patients: Pediatric fasting guidelines. Paediatr Anaesth 2011;21:964e8.
Dennhardt N, Beck C, Huber D, Sander B, Boehne M, Boethig D, et al
. Optimized preoperative fasting times decrease ketone body concentration and stabilize mean arterial blood pressure during induction of anesthesia in children younger than 36 months: A prospective observational cohort study. Paediatr Anaesth 2016;26:838-43.
Sharma V, Sharma R, Singh G, Gurkhoo S, Qazi S. Preoperative fasting duration and incidence of hypoglycemia and hemodynamic response in children. J Chem Pharm Res 2011;3:382-91.
Van Der Walt JH, Foate JA, Murrell D, Jacob R, Bentley M. A study of preoperative fasting in infants aged less than three months. Anaesth Intens Care 1990;18:527-31.
Adenekan AT. Perioperative blood glucose in a paediatric daycase facility: Effects of fasting and maintenance fluid. Afr J Paediatr Surg 2014;11:317-22.
] [Full text]
Nazari R, Calaman S, Mammen A, Bernstein B, Tan V, Bergel M, et al
. The potential consequences of fluid fasting time on hypotension during pediatric sedation while using propofol. J Clin Anesth Pain Med 2017;1:11-5.
Khanna P, Saini K, Sinha R, Nisa N, Kumar S, Maitra S. Correlation between duration of preoperative fasting and emergence delirium in pediatric patients undergoing ophthalmic examination under anesthesia: A prospective observational study. Pediatr Anesth 2018;1-5.
Jayasinghe V, Mahesh PK, Sooriaarachchi CM, Jayalath J, Karunarathne W, Liyanage SN. Evaluation of the effect of pre-operative over-fasting on post-operative vomiting in children undergoing bone marrow aspiration at a tertiary care setting in Sri Lanka: A prospective cohort study. Indian J Anaesth 2018;62:366-70.
] [Full text]
Isserman R, Elliott E, Subramanyam R, Kraus B, Sutherland T, Madu C, et al
. Quality improvement project to reduce pediatric clear liquid fasting times prior to anesthesia. Paediatr Anaesth 2019;29:698-704.
Ricci G, Amella C, Forti E, Rossi A, Bersani G, Dari S, et al
. 24-h pH metry and multichannel intraluminal impedence monitoring in obese patients with and without gastroesophageal reflux disease symptoms. Obes Surg 2011;21:48-53.
Akyuz F, Uyanikoglu A, Arici S, Akyuz U, Baran B, Pinarbasi B, et al
. Gastroeophageal reflux in asymptomatic obese subjects: An esophageal impedence–pH study. World J Gastroenterol 2015;21:3030-4.
Ayazi S, Hagen JA, Chan LS, DeMeester SR, Lin MW, et al
. Obesity and gastroesophageal reflux: Quantifying the association between body mass index, esophageal acid exposure, and lower esophageal sphincter status in a large series of patients with efflux symptoms. J Gastrointest Surg 2009;13:1440-7.
Hajar N, Castell DO, Ghomrawi H, Rackett R, Hila A. Impedance pH confirms the relationship between GERD and BMI. Dig Dis Sci 2012;57:1875-9.
Peura DA, Pilmer B, Hunt B, Mody R, Perez MC. The effects of increasing body mass index on heartburn severity, frequency and response to treatment with dexlansoprazole or lansoprazole. Aliment Pharmacol Ther 2013;37:810-8.
Hampel H, Abraham NS, El-Serag HB. Meta-analysis: Obesity and the risk for gastroesophageal reflux diseases and its complications. Ann Inrern Med 2005;143:199-211.
Wu JC, Mui LM, Cheung CM, Chan Y, Sung JJ. Obesity is associated with increased transient lower esophageal sphincter relaxation. Gastroenterology 2007;132:883-9.
Glasbrenner B, Pieramico O, Brecht-Krau D, Baur M, Malfertheiner P. Gastric emptying of solids and liquids in obesity. Clin Investig 1993;71:542-6.
Maddox A, Horowitz M, Wishart J, Collins P. Gastric and oesophageal emptying in obesity. Scand J Gastroenterol 1989;24:593-8.
Seimon RV, Brennan IM, Russo A, Little TJ, Jones KL, Standfield S, et al
. Gastric emptying, mouth-to-cecum transit, and glycemic, insulin, incretin, and energy intake responses to a mixed - nutrient liquid in lean, overweight, and obese males. Am J Physiol-Endocrinol Metab 2013;304:E294-300.
Wright RA, Krinsky S, Fleeman C, Trujillo J, Teague E. Gastric emptying and obesity. Gastroenterology 1983;84:747-51.
Buchholz V, Berkenstadt H, Goitein D, Dickman R, Bernstine H, Rubin M. Gastric emptying is not prolonged in obese patients. Surg Obes Relat Dis 2013;9:714-7.
Cardoso A, Gonzaga Vaz Coelho L, Savassi-Rocha PR, Vignolo MC, Abrantes MM, Miranda De Almeida A, et al
. Gastric emptying of solids and semi-solids in morbidly obese and non-obese subjects: An assessment using the 13C-octanoic acid and 13C-acetic acid breath tests. Obes Surg 2007;17:236-41.
Verdich C, Lysga J, Madsen Ê, Toubro S, Buemann B, Holst J, et al
. Effect of obesity and major weight reduction on gastric emptying. Int J Obes 2000;24:899-905.
Jackson SJ, Leahy FE, McGowan AA, Bluck LJC, Coward WA, Jebb SA. Delayed gastric emptying in the obese: An assessment using the non-invasive 13C-octanoic acid breath test. Diabetes Obes Metab 2004;6:264-70.
Lavigne ME, Wiley ZD, Meyer JH, Martin P, MacGregor IL. Gastric emptying rates of solid food in relation to body size. Gastroenterology 1978;74:1258-60.
Grybäck P, Näslund E, Hellström PM, Jacobsson H, Backman L. Gastric emptying of solids in humans: Improved evaluation by Kaplan-Meier plots, with special reference to obesity and gender. Eur J Nucl Med 1996;23:1562-7.
McCallum RW, Berkowitz D, Lerner E. Gastric emptying of solid food in patients with gastroesophageal reflux. Gastroenterology 1981;80:285-91.
Juvin P, Fevre G, Merouche M, Vallot T, Desmonts JM. Gastric residue is not more copiusin obese patients. Anesth Analg 2001;93:1621-2.
Mahajan V, Hashmi J, Singh R, Samra T, Aneja S. Comparative evaluation of gastric pH and volume in morbidly obese and lean patients undergoing elective surgery and effect of aspiration prophylaxis. J Clin Anesth 2015;27:396-400.
Shiraishi T, Kurosaki D, Nakamura M, Yazaki T, Kobinata S, Seki Y, et al.
Gastric fluid volume change after oral rehydration solution intake in morbidly obese and normal controls: A magnetic resonance imaging-based analysis. Anesth Analg 2017;124:1174-8.
Harter RL, Kelly WB, Kramer MG, Perez CE, Dzwonczyk RR. A comparison of the volume and pH of gastric contents of obese and lean surgical patients. Anesth Analg 1998;86:147-52.
Vaughan RW, Bauer S, Wise L. Volume and pH of gastric juice in obese patients. Anesthesiology 1975;43:686-9.
Maltby JR, Putka S, Watson NC, McTaggart RA, Fick GH. Drinking 300 mL of clear fluid two hours before surgery has no effect on gastric volume and pH fasting and non-fating obese patients. Can J Anaesth 2004;51:111-5.
Lam AM, Grace DM, Penny FJ, Vezina WC. Prophylactic intravenous cimetidine reduces the risk of acid aspiration in morbidly obese patients. Anesthesiology 1986;65:684-7.
Lam AM, Grace DM, Manning PH. The effects of cimetidine and ranitidine with and without metoclopramide on gastric volume and pH in morbidly obese patients. Can Anaesth Soc J 1986;33:773-9.
Manchikanti L, Roush JR, Colliver JA. Effect of preanesthetic ranitidine and metoclopramide on gastric contents in morbidly obese patients. Anesthesia and Analgesia 1986;65:195-9.
Mahajan V, Hashmi J, Singh R, Samra T, Aneja S. Comparative evaluation of gastric pH and volume in morbidly obese and lean patients undergoing elective surgery and effect of aspiration prophylaxis. J Clin Anesth 2015;27:396-400.
Matłok M, Pędziwiatr M, Major P, Kłęk S, Budzyński P, Małczak P. One hundred seventy-nine consecutive bariatric operations after introduction of protocol inspired by the principles of enhanced recovery after surgery (ERAS®) in bariatric surgery. Med Sci Monit 2015;21:791-7.
Cubillos J, Tse C, Chan VWS, Perlas A. Bedside ultrasound assessment of gastric content: An observational study. Can J Anesth 2012;59:416-23.
Jacoby J, Smith G, Eberhardt M, Heller M. Bedside ultrasound to determine prandial status. Am J Emerg Med 2003;21:216-9.
Bouvet L, Miquel A, Chassard D, Boselli E, Allaouchiche B, Benhamou D. Could a single standardized ultrasonographic measurement of antral area be of interest for assessing gastric contents? A preliminary report. Eur J Anaesthesiol 2009;26:1015-19.
Carp H, Jayaram A, Stoll M. Ultrasound examination of the stomach contents of parturients. Anesth Analg 1992;74:683-7.
Kruisselbrink R, Gharapetian A, Chaparro LE, Ami N, Richler D, Chan VWS, et al
. Diagnostic accuracy of point-of-care gastric ultrasound. Anesth Analg 2018. doi: 10.1213/ANE.0000000000003372.
Kruisselbrink R, Arzola C, Jackson T, Okrainec A, Chan V, Perlas A. Ultrasound assessment of gastric volume in severely obese individuals: A validation study. Br J Anaesth 2017;118:77-82.
Van de Putte P, Perlas A. Gastric sonography in the severely obese surgical patient: A feasibility study. Anesth Analg 2014;119:1105-10.
Moser JJ, Walker AM, Spencer AO. Point-of-care paediatric gastric sonography: Can antral cut-off values be used to diagnose an empty stomach? Br J Anaesth 2017;119:943-7.
Gagey AC, Siqueira Q, Desgranges FP, Combet S, Naulin C, Chassard D, et al
. Ultrasound assessment of the gastric contents for the guidance of the anaesthetic strategy in infants with hypertrophic pyloric stenosis: A prospective cohort study. Br J Anaesth 2016;116:649-54.
Gagey AC, Siqueira Q, Monard C, Combet S, Cogniat B, Desgranges FP, et al
. The effect of pre-operative gastric ultrasound examination on the choice of general anaesthetic induction technique for non-elective paediatric surgery A prospective cohort study. Anaesthesia 2018;73:304-12.
Koenig SJ, Lakticova V, Mayo PH. Utility of ultrasonography for detection of gastric fluid during urgent endotracheal intubation. Intensive Care Med 2011;37:627-31.
Mackenzie DC, Azad AM, Noble VE, Liteplo AS. Test performance of point-of-care ultrasound for gastric content. Am J Emerg Med 2019;37:123-6.
Alakkad H, Kruisselbrink R, Chin KJ, Niazi AU, Abbas S, Chan VWS, et al
. Point of care ultrasound defines gastric content and changes the anesthetic management of elective surgical patients who have not followed fasting instructions: A prospective case series. Can J Anesth 2015;62:1188-95.
Sharma G, Jacob R, Mahankali S, Ravindra MN. Preoperative assessment of gastric contents and volume using bedside ultrasound in adult patients: A prospective, observational, correlation study. Indian J Anaesth 2018;62:753-8.
] [Full text]
Sharma S, Deo AS, Raman P. Effectiveness of standard fasting guidelines as assessed by gastric ultrasound examination: A clinical audit. Indian J Anaesth 2018;62:747-52.
] [Full text]
Fujigaki T, Fukusaki M, Nakamura H, Shibata O, Sumikawa K. Quantitative evaluation of gastric contents using ultrasound. J Clin Anesth 1993;5:451-5.
Ricci R, Bontempo I, Corazziari E, La Bella A, Torsoli A. Real time ultrasonography of the gastric antrum. Gut 1993;34:173-6.
Hveem K, Hausken T, Berstad A. Ultrasonographic assessment of fasting liquid content in the human stomach. Scand J Gastroenterol 1994;29:786-9.
Tomomasa T, Tabata M, Nako Y, Kaneko H, Morikawa A. Ultrasonographic assessment of intragastric volume in neonates: Factors affecting the relationship between intragastric volume and antral cross-sectional area. Pediatr Radiol 1996;26:815-20.
Perlas A, Chan VWS, Lupu CM, Mitsakakis N, Hanbidge A. Ultrasound assessment of gastric content and volume. Anesthesiology 2009;111:82-9.
Bouvet L, Mazoit J, Chassard D, Allaouchiche B, Boselli E, Benhamou D. Clinical assessment of the ultrasonographic measurement of antral area for estimating preoperative gastric content and volume. Anesthesiology 2011;114:1086-92.
Schmitz A, Thomas S, Melanie F, Rabia L, Klaghofer R, Weiss M, et al
. Ultrasonographic gastric antral area and gastric contents volume in children. Ped Anesth 2012;22:144-9.
Perlas A, Mitsakakis N, Liu L, Cino M, Haldipur N, Davis L, et al
. Validation of a mathematical model for ultrasound assessment of gastric volume by gastroscopic examination. Anesth Analg 2013;116:357-63.
Arzola C, Perlas A, Siddiqui NT, Downey K, Ye XY, Carvalho JCA. Gastric ultrasound in the third trimester of pregnancy: A randomised controlled trial to develop a predictive model of volume assessment. Anaesthesia 2018;73:295-303.
Song IK, Kim HJ, Lee JH, Kim EH, Kim JT, Kim HS. Ultrasound assessment of gastricvolume in children after drinking carbohydrate-containing fluids. Br J Anaesth 2016;116:513-7.
Bouvet L, Bellier N, Gagey-Riegel AC, Desgranges FP, Chassard D, De Queiroz Siqueira M. Ultrasound assessment of the prevalence of increased gastric contents and volume in elective pediatric patients: A prospective cohort study. Pediatr Anesth 2018;28:906-13.
Amaral CK, Benevides ML, Benevides MM, Sampaio DL, Fontes CJF. Ultrasound assessment of gastric antrum in term pregnant women before elective caesarean section. Rev Bras Anestesiol 2019;69:266-71.
Zieleskiewicz L, Boghossian MC, Delmas AC, Jay L, Bourgoin A, Carcopino X, et al
. Ultrasonographic measurement of antral area for estimating gastric fluid volume in parturients. Br J Anaesth 2016;117:198-205.
Roukhomovsky M, Zieleskiewicz L, Diaz A, Guibaud L, Chaumoitre K, Desgranges FP, et al
. Ultrasound examination of the antrum to predict gastric content volume in the third trimester of pregnancy as assessed by MRI. Eur J Anaesthesiol 2018;35:379-89.
Holt S, Cervantes J, Wilkinson AA, Wallace JHK. Measurement of gastric emptying rate in humans by real-time ultrasound. Gastroenterology 1986;90:918-23.
Hveem K, Jones KL, Chatterson BE, Hrowitz M. Scintigraphic measurement of gastric emptying and ultrasonographic assessment of antral area: Relation to appetite. Gut 1996;38:816-21.
Darwiche G, Bjorgell O, Thorsson O, Almer L-O. Correlation between simultaneous scintigraphic and ultrasonographic measurement of gastric emptying in patients with type 1 diabetes mellitus. J Ultrasound Med 2003;22:459-66.
Sharma V, Gudivada D, Gueret R, Bailitz J. Ultrasound-assessed gastric antral area correlates with aspirated tube feed volume in enterally fed critically ill patients. Nutr Clin Pract 2017;32:206-11.
Schmitz A, Schmidt AR, Buehler PK, Schraner T, Frühauf M, Weiss M, et al.
Gastric ultrasound as a preoperative bedside test for residual gastric contents volume in children. Paediatr Anaesth 2016;26:1157-64.
[Table 1], [Table 2]