Indian Journal of Anaesthesia  
About us | Editorial board | Search | Ahead of print | Current Issue | Past Issues | Instructions
Home | Login  | Users Online: 1067  Print this pageEmail this pageSmall font sizeDefault font sizeIncrease font size    




 
 Table of Contents    
REVIEW ARTICLE
Year : 2018  |  Volume : 62  |  Issue : 10  |  Page : 738-742  

Perioperative stroke – Prediction, Prevention, and Protection


Department of Anaesthesia, Kamalnayan Bajaj Hospital, Aurangabad, Maharashtra, India

Date of Web Publication9-Oct-2018

Correspondence Address:
Dr. Amarja S Nagre
C 3 Row House, Muthiyan Residency, Deepnagar, Aurangabad, Maharashtra
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ija.IJA_292_18

Rights and Permissions
 


Stroke culminates into 6.2 million deaths annually and is thereby a leading cause of disability and death worldwide. In patients undergoing noncardiac, nonneurological surgery, perioperative stroke can eventuate into a catastropic aftermath with almost eight-fold rise in mortality. In cardiac, neurological, and carotid surgery, stroke rate accounts to be high (2.2%–5.2%) and is a significant instigator of morbidity and mortality as well. These facts kindle interest to review the predictive parameters, preventive measures, and all the possibilities in the management and protection against perioperative stroke.

Keywords: Atrial fibrillation, coronary artery bypass surgery, ischaemic stroke, noncardiac surgery, nonneurological surgery, perioperative stroke, risk factors, stroke, stroke prevention


How to cite this article:
Nagre AS. Perioperative stroke – Prediction, Prevention, and Protection. Indian J Anaesth 2018;62:738-42

How to cite this URL:
Nagre AS. Perioperative stroke – Prediction, Prevention, and Protection. Indian J Anaesth [serial online] 2018 [cited 2018 Dec 12];62:738-42. Available from: http://www.ijaweb.org/text.asp?2018/62/10/738/242885




   Introduction Top


The surgical population ascribes up to six times higher risk of stroke than normal.[1] Anaesthesia and surgery per se accentuate the risk of perioperative stroke (PS), more so with emergent surgeries. Surgery essentially precipitates systemic inflammation and hypercoagulability, thereby contributes to thrombogenesis and rupture of vessel plaque in the perioperative settings.[2]

History of cerebrovascular disease (stroke or transient ischaemic attack [TIA]) is one of the component of the integrated perioperative risk evaluation scores, such as the revised cardiac risk index by Lee et al.[3],[4] Currently, the incidence of perioperative ischaemic stroke in noncardiac, nonneurological, and nonmajor vascular surgery ranges from approximately 0.1% to 1.9%.[2] Moreover, stroke after cardiac surgery is debilitating and has profound repercussions effecting increased hospital stay and in-hospital mortality.[5],[6],[7] Besides, in coronary artery bypass grafting (CABG) surgery, PS is an independent predictor of mortality and morbidity.[8]


   Methods Top


An online literature search was performed using the following keywords: stroke, perioperative stroke, coronary artery bypass surgery, ischaemic stroke, risk factors, noncardiac surgery, and nonneurological surgery. The various engines searched were PubMed, NIH.gov, ScienceDirect, Cochrane data base, and Google.com. The relevant articles were included for the purpose of review. A manual search of references from relevant articles was also carried out, and various textbooks of anesthesiology were reviewed for relevant literature.


   Definition Top


The world health organization has described stroke as rapidly developing signs of focal or global disturbance of cerebral function with symptoms lasting for a day or longer or leading to death with no apparent cause other than vascular origin, whereas the PS is defined as that arising in the perioperative period, which is intraoperative or within 3–30 days following surgery.[1],[9]


   Prediction by Risk Factors of Perioperative Stroke Top


It is increasingly recognized that one can identify a high-risk patient for PS.[10] Risk factors in the general population for stroke are age, male gender,[11] heredity, obesity, diabetes mellitus, hypertension, smoking, physical inactivity, acute stress[12],[13] and h/o migrane, previous stroke, and renal failure or dysfunction. The cardiovascular causes are essentially valvular heart diseases like mitral stenosis, atrial fibrillation (AF), left atrial enlargement, ischemic heart disease, and congestive heart failure.[2] Furthermore, the risk factors are TIA, thrombotic risks with polycythaemia, increased fibrinogen, decreased antithrombin III, pregnancy, and oral contraception.[1]

These risk factors can be assorted into modifiable factors, namely, antithrombotic drugs, beta blockers, hypotension, and hypercoagulability, and nonmodifiable factors being age, previous stroke, and renal failure.[14]

Macellari et al. have done extensive literature search in their study and state that the procedure-related risk factors are primarily the timing of surgery (urgent or elective), type and duration of surgery, type of anaesthesia (general versus regional anaesthesia), intraoperative complications (such as arrhythmias and sustained hypotension), hyperglycaemia, dehydration, and blood loss.[7]

Additional risk factors in the case of CABG surgery are the chronic renal insufficiency, recent myocardial infarction, moderate to severe left ventricular dysfunction, and low cardiac output syndrome.[6] Also, arrhythmias and combined CABG with mitral or aortic or both valve surgeries carry risk.

Age

The incidence increases with age as much as six-fold rise in octagenerians and above. Advanced age is not a cause of stroke per se but rather a marker of increased atherosclerotic burden.[15] The PS risk is higher in an older patient with cardiovascular disease than a younger patient with no risk factors for vascular disease.[16] Besides, advanced age is associated with more undiagnosed cerebrovascular diseases[17] and there is a cumulative risk, over time, of coexistent hypertension, atherosclerosis, diabetes mellitus, and cardiac diseases.[10]

Previous stroke

A patient with history of previous stroke merits special attention as it is a strong predictor of PS.[18] Up to 85% patients survive first episode of stroke and remain at risk for future cerebrovascular complications.[9] In cardiac surgery, history of cerebrovascular disease is the strongest preoperative predictor of stroke.[15] Likewise, carotid artery occlusive disease and atherosclerosis of the ascending aorta have increased incidence of stroke after cardiac operations.[19]

Atrial fibrillation

It leads to thromboembolism and global hypoperfusion due to fast ventricular rate and subsequent hypotension. In patients for cardiac or noncardiac surgery, new onset perioperative AF has long-term risk of subsequent stroke and is a comorbid diagnosis.[7],[14]

Acute renal failure forms an independent risk factor for PS in noncardiac nonneurosurgical patients.[14]

Recent myocardial infarction

Recent myocardial infarction within 24 hours before CABG was associated with three times higher risk of stroke. A higher incidence of stroke after recent myocardial infarction is probably related to the haemodynamic instability, increased blood thrombogenicity, and pronounced sympathetic activation in postmyocardial infarction patients.[6]

Diabetes and peripheral vascular disease are also independent predictors of stroke, wherein patients are at increased risk of atherosclerotic embolization and impaired autoregulation of cerebral blood flow.[15]

Previous cardiac surgery is also identified as a risk factor for stroke.[15]


   Pathophysiology Top


Surgery triggers acute systemic inflammatory response. It initiates and exacerbates ischaemic cerebral injury, thrombosis, embolism, small vessel obstructions, and watershed infarctions.[20] Majority of perioperative cerebral events occur within 7 postoperative days. The venous thrombosis, alterations in clotting factors and platelets, and fibrinolyisis all lead to hypercoagulability state in the postoperative period.[1]

PS are essentially ischaemic, the reason being cerebral atherosclerosis, hypercoagulability, and hypotension. Thrombotic stroke ensues from hypercoagulability albeit cardioembolic stroke results from disease states such as AF.[2] According to the American Heart Association and American Stroke Association (AHA/ASA), haemorrhagic stroke is a focal collection of blood within the brain parenchyma, subarachnoid space, or ventricular system that is not caused by trauma. Perioperatively, this may plausibly occur due to factors, such as uncontrolled hypertension, cerebral vascular malformations, and anticoagulant or antiplatelet agents. Fortunately, haemorrhagic stroke represents only 1%–4% of all PS.[2],[14]

As it may be, in acute stroke, the cerebral autoregulation is impaired and cerebral blood flow (CBF) depends on cerebral perfusion pressure (CPP). This impairment in cerebral autoregulation peaks at 5 days after stroke and recovers over 3 months period during which the cerebral perfusion depends on systemic blood pressure.[14] Hence, during this period, maintaining the systemic blood pressure is crucial to maintain the CPP.


   Prevention of Perioperative Stroke Top


The intent of preventive strategy is to improve perioperative care inculcating modifications of the risk factors and the risk management, designed with the policy to prevent both primary and secondary strokes. Primary stroke is a stroke occurring in a patient with no history of stroke, whereas secondary stroke occurs in a patient who has already had a stroke or TIA. The fundamental prevention plans are primarily focused around the variables such as cessation of smoking, anticoagulation for AF, antihyperlipidaemic medications, and glycaemic control. In-hospital initiation of secondary prevention therapy yields high rates of adherence in the stroke due to thromboembolic events.[21] Hypercoagulability check and withholding of anticoagulants[7] are pivotal in the prevention policy.

The fundamentals to be considered in cases wherein preoperative carotid artery revascularization is needed are in case of >70% symptomatic carotid stenosis, the carotid stenting, or endarterectomy before elective surgery should be offered. For <50% stenosis, it is not indicated, albeit in asymptomatic patients with >60% stenosis, surgery favors the outcome as per European asymptomatic carotid surgery trial.[20],[22]

Time of elective surgery

In a patient with existing preoperative stroke for elective noncardiac surgery, a prudent approach is to delay the surgery to reduce perioperative risk. The Society for Neuroscience in Anesthesiology and Critical Care (SNACC) recommends a delay of at least 1 month between stroke and elective surgery. The data analysis by Jorgensen et al. suggest that elective surgery should be deferred until 6 months after a stroke owing to the plausible association of increased risks of PS and mortality.[18]

Statins

Patients with previous stroke may be on statins for secondary stroke prevention. Statins withdrawal in patients with acute stroke has 8.7-fold rise in the risk for early neurological deterioration.[20] and is also associated with increased risk of death or dependency. Hence, it should be continued in the acute phase of ischaemic stroke or should be initiated 2 weeks prior to the surgery to decrease the risk of PS.[23],[24] Though statins act through various pathways, the anti-inflammatory effects in particular confer stroke protection.[2]

Antiplatelet drugs

Aspirin is recommended to be continued, whereas clopidogrel is stopped 5–7 days prior to surgery.[14] Oral anticoagulants are stopped 5 days before major surgery and patients who are at high risk of thromboembolism should receive bridging anticoagulation with subcutaneous low-molecular-weight heparin (LMWH) or intravenous (IV) unfractionated heparin.[25]

Antithrombotic agents

The risk of thromboembolism needs to be counterbalanced with the risk of bleeding.[7] Vitamin K antagonists, namely, warfarin, should be stopped 5 days prior to surgery. Bridging anticoagulation is recommended in high-risk patients like AF with CHADS score (a scoring system for risk estimation of stroke in patients with nonrheumatic AF based on presence of congestive cardiac failure, hypertension, advanced age, diabetes, or stroke) >4, prosthetic heart valve, history of venous thromboembolism, previous stroke, or TIA within 6 months.[14] Landercasper J et al. in their study on PS risk studied 173 consecutive patients with a history of previous cerebrovascular accident who underwent general anaesthesia for surgery. Five patients (2.9%) had documented postoperative cerebrovascular accidents from 3 to 21 days after surgery and also state the finding that postoperative stroke was more common in patients on preoperative heparin sodium.[26]


   Protection and Management Strategy of Perioperative Stroke Top


The management of PS is predominantly based on the general supportive care and prevention of complications.[20] It also aims toward re-establishment of blood supply to the ischaemic areas of brain.[14] Partial airway obstruction, hypoventilation, aspiration, pneumonia, and atelectasis can lead to hypoxia that may worsen the brain injury, hence needs to be addressed instantaneously.[20] Early recognition leads to better neurological outcome after PS. Sedation can mask presenting clinical features, thereby minimizing sedation in suspected cases helps earlier detection of stroke.[14]

Investigations

Ischaemic stroke can be differentiated from intracranial haemorrhage and nonvascular causes of neurological symptoms like tumors by noncontrast computerised tomography (CT). Additional information can be sought by multimodal CT and magnetic resonance imaging as well.[20] The atherosclerotic disease of the ascending aorta can be identified using transesophageal echocardiography.[27] Neuromonitoring, such as electroencephalography and somatosensory evoked potential monitoring, helps to detect decrease in the CBF.[23] Monitoring cerebral ischaemia with transcranial Doppler or electroencephalogram and evoked potentials is quite reasonable.[20] Also, cerebral oximetry and jugular bulb venous oximetry are pivotal. Carotid duplex ultrasonography may identify significant carotid disease in high-risk patients.[6]

The treatment aims toward considering the following points in the protection against PS.

Intraoperative and postoperative hypotension

Judicious management of hypotension needs to be done in the intra- and postoperative period, more so in the suspect cases as Peri Operative Ischemic Evaluation Study (POISE) trial suggests that hypotension might contribute to the risk of stroke. As stated by Bijker et al., 30% decrease in mean arterial pressure from immediately preoperative baseline is associated with ischaemic stroke within 10 days of general surgery (odds ratio: 1.013; 95% CI: 1.000–1.025).[28] Moreover, cautious management of blood pressure in severely hypertensive patients seems prudent considering the risk of precipitating ischaemic stroke during aggressive blood pressure reduction.[15] Additionally, the hypotension particularly in the recovery period has been noted as a predictive event.[9]

Normoglycaemia

Hyperglycaemia worsens brain injury.[9] Current expert consensus recommends treating hyperglycaemia >150 mg/dL with a target glucose range of 60–180 mg/dL.[14]

Beta-blockers and Angiotensin converting enzyme inhibitors

Perioperative beta-blockade has emerged as a risk factor for stroke across the general surgical population. Further, there exists increased risk with nonselective beta-blockers.[2] The POISE-1 trial demonstrated that perioperative metoprolol in noncardiac surgical patients with cardiovascular risk factors was associated with a significantly higher incidence of stroke and mortality. The observational studies in noncardiac surgical populations also suggest that routine administration of metoprolol is associated with a higher risk of stroke compared with other beta-blockers with more selectivity for the β1 adrenergic receptor, such as atenolol or bisoprolol.[18] Angiotensin converting enzyme inhibitors (ACEIs) can cause hypotension not responding even to vasopressors that forms the risk factor for PS. Therefore, the risk benefit ratio needs to be balanced and accordingly preoperative beta-blockers, statins, and ACEI therapy should be continued albeit monitored earnestly in the perioperative period.[25]

Type of surgery

The incidence of PS depends on the type of surgery as the following figures suggest. The type of surgery and the incidences are as follows: general surgery 0.08%–0.7%, orthopedic surgery 0.2%–0.9%, lung operations 0.6%–0.9%, and head and neck surgery 4.8%. CABG surgery has highest incidence of major ischaemic complications (3%–5%) and up to 80% suffer cognitive dysfunction.[1]

Other neuroprotective strategies

These include use of drugs like thiopentone, isoflurane, sevoflurane, magnesium, and hypothermia.[29] The advanced treatment of acute stroke includes thrombolysis, and mechanical recanalization of occluded arteries and administration of heparin are not suitable for patients after surgery.[20] Intravenous alteplase (recombinant tissue plasminogen activator) is the only approved thrombolytic agent at present indicated for acute ischaemic stroke.[30] IV alteplase is recommended for selected patients who may be treated within 3 hours of ischaemic stroke and can be extended up to 4.5 hours.[31] Such thrombolysis is relatively contraindicated within 14 days after a major surgery[14],[20] Intracranial haemorrhage is the major complication associated with it.[30] Also, IV alteplase should not be administered to patients who have received a treatment dose of low-molecular-weight heparin within the previous 24 hours.[31]


   Summary Top


PS is a potentially ruinous complication of surgery. It deserves attention because of the serious debility and associated mortality. The author reiterates the importance of scrupulous preoperative evaluation to identify the possible risk factors. Haemodynamic stability in the perioperative period certainly is a fundamental fix. With the rigorous management strategies, PS can be successfully halted to a minimum.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Gelb AW, Cowie DA. Perioperative stroke prevention. Anesth Analg 2001;92:46-53.  Back to cited text no. 1
    
2.
Vlisides P, Mashour GA. Perioperative stroke. Can J Anaesth 2016;63:193-204.  Back to cited text no. 2
    
3.
Jorgensen ME, Torp-Pedersen C, Gislason GH, Jensen PF, Berger SM, Christiansen CB, et al. Time elapsed after ischemic stroke and risk of adverse cardiovascular events and mortality following elective noncardiac surgery. JAMA 2014;312:269-77.  Back to cited text no. 3
    
4.
Rupert E. Preoperative assessment of cardiac risk. Indian J Anaesth 2007;51(4):269-78.  Back to cited text no. 4
    
5.
Dacey LJ, Likosky DS, Leavitt BJ, Lahey SJ, Quinn RD, Hernandez F Jr, et al. Perioperative stroke and long-term survival after coronary bypass graft surgery. Ann Thorac Surg 2005;79:53237.  Back to cited text no. 5
    
6.
Stamou SC, Hill PC, Dangas G, Pfister AJ, Boyce SW, Dullum MK, et al. Stroke after coronary artery bypass: Incidence, predictors, and clinical outcome. Stroke 2001;32:1508-13.  Back to cited text no. 6
    
7.
Macellari F, Paciaroni M, Agnelli G, Caso V. Perioperative stroke risk in nonvascular surgery. Cerebrovasc Dis 2012;34:175-81.  Back to cited text no. 7
    
8.
Mehta A, Gleason T, Wechsler L, Winger D, Wang L, Thirumala PD. Perioperative stroke as a predictor of mortality and morbidity in patients undergoing CABG. J Clin Neurosci 2017;44:175-9.  Back to cited text no. 8
    
9.
Kim J, Gelb AW. Predicting perioperative stroke. J Neurosurg Anesthesiol 1995;7:211-5.  Back to cited text no. 9
    
10.
Menon U, Kenner M, Kelley RE. Perioperative stroke. Expert Rev Neurother 2007;7:1003-11.  Back to cited text no. 10
    
11.
Wong GY, Warner DO, Schroeder DR, Offord KP, Warner MA, Maxson PM, et al. Risk of surgery and anesthesia for ischemic stroke. Anesthesiology 2000;92:425-32.  Back to cited text no. 11
    
12.
Parikh S, Cohen JR. Perioperative stroke after general surgical procedures. N Y State J Med 1993;93:162-5.  Back to cited text no. 12
    
13.
Dunstan C, Jerwood C. Perioperative stroke: Implications of anesthetic technique. Anaesthesia 2007;62:853.  Back to cited text no. 13
    
14.
Chiao SS, Zuo ZY. Approach to risk management of perioperative stroke. J Anesth Perioper Med 2015;2:268-76.  Back to cited text no. 14
    
15.
Bucerius J, Gummert JF, Borger MA, Walther T, Doll N, Onnasch JF, et al. Stroke after cardiac surgery: A risk factor analysis of 16,184 consecutive adult patients. Ann Thorac Surg 2003;75:472-8.  Back to cited text no. 15
    
16.
Kelley RE. Stroke in the postoperative period. Med Clin North Am 2001;85:1263-76.  Back to cited text no. 16
    
17.
Goto T, Maekawa K. Cerebral dysfunction after coronary artery bypass surgery. J Anesth 2014;28:242-8.  Back to cited text no. 17
    
18.
Sanders RD, Jørgensen ME, Mashour GA. Perioperative stroke: A question of timing? Br J Anaesth 2015;115:11-3.  Back to cited text no. 18
    
19.
Wareing TH, Davila-Roman VG, Daily BB, Murphy SF, Schechtman KB, Barzilai B, et al. Strategy for the reduction of stroke incidence in cardiac surgical patients. Ann Thorac Surg 1993;55:1400-8.  Back to cited text no. 19
    
20.
Ng JL, Chan MT, Gelb AW. Perioperative stroke in noncardiac, non-neurosurgical surgery. Anesthesiology 2011;115:879-90.  Back to cited text no. 20
    
21.
Slark J, Sharma P. Risk awareness in secondary stroke prevention: A review of the literature. JRSM Cardiovasc Dis 2014;3:1-6.  Back to cited text no. 21
    
22.
Ricotta JJ, Aburahma A, Ascher E, Eskandari M, Faries P, Lal BK. Updated society for vascular surgery guidelines for management of extracranial carotid disease. J Vasc Surg 2011;54:e1-31.  Back to cited text no. 22
    
23.
Engelhard K. Anaesthetic techniques to prevent perioperative stroke. Curr Opin Anaesthesiol 2013;26:368-74.  Back to cited text no. 23
    
24.
Blanco M, Nombela F, Castellanos M, Rodriguez-yanez M, Garcia-Gil M, Leira R, et al. Statin treatment withdrawal in ischemic stroke. A controlled randomized study. Neurology 2007;69:904-10.  Back to cited text no. 24
    
25.
Brooks DC, Schindler JL. Perioperative stroke: risk assessment, prevention and treatment. Curr Treat Options Cardio Med 2014;16:282.  Back to cited text no. 25
    
26.
Landercasper J, Merz BJ, Cogbill TH, Perioperative stroke risk in 173 consecutive patients with a past history of stroke. Arch Surg 1990;125:986-9.  Back to cited text no. 26
    
27.
Palmerini T, Savini C, Eusanio MD. Risks of stroke after coronary artery bypass graft – Recent insights and perspectives. Interv Cardiol Rev 2014;9:77-83.  Back to cited text no. 27
    
28.
Bijker JB, Persoon S, Peelen LM, Intraoperative hypotension and perioperative ischemic stroke after general surgery: A nested case-control study. Anesthesiology 2012;116:65864.  Back to cited text no. 28
    
29.
Anastasian, ZH. Anaesthetic management of the patient with acute ischaemic stroke. Br J Anaesth 2014;113(Suppl 2):ii9-16.  Back to cited text no. 29
    
30.
Robinson T, Zaheer Z, Mistri AK. Thrombolysis in acute ischaemic stroke: An update. Ther Adv Chronic Dis 2011;2:119-31.  Back to cited text no. 30
    
31.
Powers WJ, Rabinstein AA, Ackerson T, Adeoye OM, Bambakidis N, Becker K, et al. 2018 Guidelines for the early management of patients with acute ischemic stroke: A guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke 2018;49:1-244.  Back to cited text no. 31
    




 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
   Methods
   Definition
    Prediction by Ri...
   Pathophysiology
    Prevention of Pe...
    Protection and M...
   Summary
    References

 Article Access Statistics
    Viewed1209    
    Printed17    
    Emailed0    
    PDF Downloaded405    
    Comments [Add]    

Recommend this journal