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Year : 2019  |  Volume : 63  |  Issue : 4  |  Page : 319-321  

Foreign body obstructing fresh gas flow through disposable breathing circuit

Department of Anaesthesiology and Pain Relief, Kidwai Cancer Institute, Bengaluru, Karnataka, India

Date of Web Publication4-Apr-2019

Correspondence Address:
Dr. Kavitha Lakshman
Department of Anaesthesiology and Pain Relief, Kidwai Cancer Institute, Dr. M H Marigowda Road, Bengaluru - 560 029, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ija.IJA_772_18

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How to cite this article:
Lakshman K, Philip JH, Ravikiran H M, Ranganath N. Foreign body obstructing fresh gas flow through disposable breathing circuit. Indian J Anaesth 2019;63:319-21

How to cite this URL:
Lakshman K, Philip JH, Ravikiran H M, Ranganath N. Foreign body obstructing fresh gas flow through disposable breathing circuit. Indian J Anaesth [serial online] 2019 [cited 2021 May 11];63:319-21. Available from: https://www.ijaweb.org/text.asp?2019/63/4/319/255460


The presence of an unrecognised 'foreign body' in the anaesthetic equipment has the potential to cost a human life. The Association of Anaesthetists of Great Britain and Ireland [AAGBI] have given guidelines for conducting pre-use machine check.[1]

We present a case of 56-year-old female patient with carcinoma breast posted for modified radical mastectomy. History, physical examination and blood investigations were unremarkable except for hepatitis-B-surface-antigen positive serology. On the day of the procedure we followed automated check-out on Drager-Fabius machine. A disposable circuit (K&L-KyolingR) was used. Two-bag test was done. Standard anaesthesia monitors were connected on patient and midazolam intravenous [IV] 1 mg was given. During preoxygenation, the patient became very anxious and was feeling claustrophobic with a well-fitting face-mask and good-seal. She was reassured and oxygen insufflated through face-mask and general anaesthesia was induced with propofol IV-100mg and fentanyl IV-80μg. We noticed that we were not able to mask ventilate the lungs. Anticipating tongue fall, we used an oral-airway and improved the mask-seal, but could not ventilate the lungs. There was no visible chest rise. Rising airway pressure on monitors and increased compliance of the bag were appreciated. The bag began to distend despite the adjustable-pressure-limiting [APL] valve being minimally closed. Sensing equipment malfunction we disconnected the circuit to use artificial-manual-breathing-unit [AMBU] for ventilation. On disconnecting the circuit we noticed a cap jammed into the mask which was acting like a foreign-body preventing fresh-gas-flow [Figure 1]. We were able to ventilate the patient using breathing circuit after removing the foreign-body. The rest of case went uneventfully.
Figure 1: Foreign body -Cap obstructing the face mask

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On analysis, it was found out that the cap which was jammed in face-mask was part of disposable breathing circuit. This cap was inadvertently not removed before connecting to the mask. On disconnecting the mask to perform Two-bag test prior to use, the cap was retained in the anatomic face-mask. After clearing the leak test, the circuit was reconnected to the mask having the retained cap.

The diagnosis of a blocked breathing circuit as the cause for failure to ventilate the patient is of paramount importance in ameliorating a life threatening situation as this may mimic other clinical conditions of silent chest[2] where our attention will be diverted leaving the machine component unattended. Both device related and human factors can contribute to the mishap during induction. Better understanding of anaesthesia machine and checking its each component for proper functioning prior to use may minimise the catastrophic events.[3]

This incident could have been avoided by visual inspection during assembly of the breathing circuit, circuit cap of different colour from that of circuit would have been easily identifiable and by use of a translucent mask instead of the opaque anatomical face mask that obscured the view of the cap inside. Old school practice of feeling for fresh gas flow by operator before use also could have hinted at obstruction to flow. Preoxygenation with well-fitting face-mask would have hinted at obstruction much earlier due to absence of bag movement.

Availability of AMBU cannot be over emphasised. AMBU is failsafe in case of equipment malfunction leading to failed gas delivery to patient. We could save precious time by ventilating patient with AMBU when we are not able to ventilate using anaesthesia machine.

Mechanical obstruction in the ventilator circuit due to heat-moisture-exchange filter, IV-cannula cap, faulty equipment or unusual bodies like plastic wrapping have been reported leading to unfortunate events.[4]

This article highlights that anaesthesiologists and technicians should inspect breathing circuit for correct configuration, assembly and proper functioning. Breathing systems should be protected at patient end when not in use to prevent intrusion of foreign-body. The cap may have been provided by manufacturer of the disposable-circuit to prevent any foreign body intrusion while not in use.[3],[5]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Anderson E, Bythell V, Gemmell L, Jones H, McIvor D, Pattinson A, et al. Checking anaesthetic equipment 2012. Anaesthesia 2012;67:660-8.  Back to cited text no. 1
Looseley A. Management of bronchospasm during general anaesthesia. Update Anaesth 2011;27:17-21.  Back to cited text no. 2
Expert Group on blocked anaesthetic tubing, UK. Protecting the breathing circuit in anaesthesia-Report to the Chief Medical Officer of an expert group on blocked anaesthetic tubing [Internet]. 2004. Available from: http://www.frca.co.uk/documents/Protecting%20the%20PBC.pdf. [Last cited on 2019 Jan 02].  Back to cited text no. 3
Jain D, Bala I. Breathing circuit obstruction: An unusual case. Saudi J Anaesth 2013;7:492-3.  Back to cited text no. 4
[PUBMED]  [Full text]  
Wicker P, Smith B. Checking the anaesthetic machine. J Perioper Pract 2006;16:585-90.  Back to cited text no. 5


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