|LETTER TO EDITOR
|Ahead of print publication
Trivia of an unnoticed miscreant at the glottis resulting in an unanticipated difficult airway
Sumit Roy Chowdhury, Amit kumar Malviya, Anju Gupta
Department of Anaesthesia, Pain Medicine and Critical Care, All India Institute of Medical Sciences, New Delhi, India
|Date of Submission||21-Jan-2022|
|Date of Decision||17-Mar-2022|
|Date of Acceptance||02-May-2022|
|Date of Web Publication||05-Jul-2022|
437 Pocket A, Sarita Vihar, New Delhi - 110 076
Source of Support: None, Conflict of Interest: None
|How to cite this URL:|
Chowdhury SR, Malviya Ak, Gupta A. Trivia of an unnoticed miscreant at the glottis resulting in an unanticipated difficult airway. Indian Anaesth Forum [Epub ahead of print] [cited 2022 Aug 10]. Available from: http://www.theiaforum.org/preprintarticle.asp?id=349811
Unanticipated difficult airway is a rarely encountered event in day-to-day anesthesiology practice. We report one such interesting and challenging case where an unexpected difficulty in bag and mask ventilation (BMV) was encountered due to a rare cause. A 55-year-old, average-built reformed smoker with a diagnosis of biliary peritonitis was posted for exploratory laparotomy. He had no other comorbid illness, and systemic examination was unremarkable. Airway examination revealed multiple oral ulcers, Mallampati class-II, an inter-incisor gap of 3 cm, normal neck distances, and movements.
Modified rapid sequence induction was planned, and after preoxygenation, general anesthesia was induced by administering fentanyl, thiopentone, and rocuronium. After induction and application of cricoid pressure, gentle BMV was attempted with an appropriately sized mask by a senior anesthesiologist. However, there was no chest movement, and end-tidal carbon dioxide was not recordable despite attempts to optimize the mask seal. Meanwhile, 60 s had passed, so the intubation was attempted using a Macintosh blade which yielded a Cormack–Lehane Grade-III glottic view, and the trachea could not be intubated. A videolaryngoscope (VL) was asked for, and meanwhile, BMV was initiated but was not effective even with the head tilt and jaw thrust, two-hand technique, release of cricoid pressure, and use of oropharyngeal airway. Arterial oxygen saturation (SpO2) was still 99% (150 s since muscle relaxant), and intubation was attempted with a VL (CMAC; Karl Storz, Tuttlingen, Germany). A large thick mucous plug was seen covering the entire glottic chink [Figure 1]a. Mucous plug had to be removed using Magill's forceps and Yankauer suction before glottic chink could be visualized [Figure 1]b. Following intubation, multiple further chunks of thick mucous were removed with forceps and suction.
|Figure 1: (a) Mucous plug covering entire glottis; (b) Mucous plug removed with a Magill's forceps|
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Airway obstruction has been categorized according to the site, i.e., oropharyngeal, the base of tongue, epiglottic, glottic, or tracheal. Out of these, epiglottic, glottic, or tracheal obstructions are not apparent on clinical airway examination and may be totally missed in the scenarios of the absence of signs and symptoms such as stridor, dyspnea, or voice changes. Slowly progressive airway obstruction allows the respiratory muscles to become conditioned to generate the required negative pressure to overcome the obstruction, thereby presenting with few or none of these symptoms as seen in the index case.
All India Difficult Airway Association guidelines for the management of the difficult airway have addressed both anticipated and unanticipated difficult airways. The present case would typify both difficult to ventilate (due to physical obstruction by the mucous plug) and difficult to intubate cases (due to inability to visualize the glottis). The organized mucous plug at the laryngeal inlet precludes mask ventilation and obstructs the airway beyond the benefits of oral airway or laryngeal mask airways, which are a part of troubleshooting ventilation difficulty in difficult airway algorithms.
A mucous plug or blood clot, blocking the endotracheal tube has been reported in previous instances, but the index case describes a mucous plug obstructing the airway before intubation. The patient was possibly maintaining oxygenation by negative pressure inspiration through a small chink in the membrane formed by the thick mucous. While a valve mechanism would possibly explain why repeated efforts of repositioning and use of oral airway were not fruitful during positive pressure ventilation.
Different existing guidelines provide us an algorithm to manage a difficult airway. However, in instances like this, the attending anesthetist may need to think out of the box to rule out other causes of supraglottic obstruction, which may not be apparent during routine preoperative airway examination. This case underlines the need for awareness of an unanticipated upper airway obstruction by a mucous clog and to consider it as a differential diagnosis when unexpected difficulty arises during BMV.
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.
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