How do junior anaesthetists manage the obese airway?

Published Date: 12th February 2018

Publication Authors: Khirwadkar R, Salvage G, Spilsbury Z

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In 2014, it was estimated that 35% of men and 28% of women would be obese, rising to 47% and 36% respectively by 2025.

Methods

Based on the Society for Obese & Bariatric Anaesthetist's (SOBA) guidelines, we retrospectively collected data regarding airway management for obese patients undergoing emergency surgery.

Results

All patients (n = 49) had a BMI > 35. Thirty-seven patients were intubated and 11 received supraglottic airway (SGA) devices. One patient's airway was managed with a facemask. Of the 24 patients who received a rapid sequence induction, 8 (33.3%) received sub-therapeutic doses of their muscle relaxant (rocuronium or suxamethonium). Seven patients (14%) had documented difficult airways; 2 required 3 attempts at intubation, 2 could not be ventilated by mask, 1 was difficult to ventilate after intubation and 2 had documented aspiration. Twenty patients (28.5%) reported postoperative complications; 4 had documented hypoxia, 3 had postoperative pneumonias, 2 had aspiration, 1 had a cardiac arrhythmia and 4 had unplanned intensive care admissions.

Discussion

SGAs have been associated with a fourfold increase in incidence of airway catastrophes in obese patients [2]. Therefore it is recommended that obese patients are intubated. Of the 12 (25%) patients who did not receive an endotracheal tube, 2 had a documented aspiration. Although many of our anaesthetists used a SGA as a calculated risk in the obese population, our data suggest that SGAs carry an unacceptable aspiration risk, in keeping with the SOBA guidance. Loss of airway control is more likely in patients who are inadequately paralysed. Our data suggest that anaesthetists are frequently underdosing their patients for rapid sequence inductions and therefore further exposing their patients to a higher risk of a difficult airway. While this may be a product of using ‘1 vial’ of a given drug, it may suggest that anaesthetists are not considering weight adjusted doses for muscle relaxants in rapid sequence inductions. A proper use of muscle relaxants is imperative to reduce the risk of difficult intubation. Our results confirm that obese patients are a high risk group with a significant risk of difficult intubation and postoperative complication. Ongoing education using SOBA's recommendations for airway management will reduce anaesthetic complications and therefore encourage more positive outcomes in the obese population.

Spilsbury Z; Salvage, G; Khirwadkar, R. (2018). 64. How do junior anaesthetists manage the obese airway? A retrospective analysis of airway management, drug dosing, difficult airway incidence and postoperative complications . Anaesthesia. 73 (S2), 40

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