Mil Med. 2018 Jun 19. doi: 10.1093/milmed/usy144. [Epub ahead of print]

# Non-conventional utilization of the Aintree intubation catheter to facilitate exchange between three supraglottic airways and an endotracheal tube: a cadaveric trial.

Lopez N, McCoy S, Carroll C, Jones E, Miller J

Background: Two studies by Bledsoe et al and Anand et al reported limited efficacy of the Supraglottic Airway Laryngeal Tube (SALT), which is a supraglottic airway (SGA) specifically designed for blind endotracheal intubation. Miller et al reported a 50% success rate using an Eschmann introducer as an adjunct for blind airway exchange via the laryngeal mask airway (LMA) classic. Another study by Ueki et al found that endotracheal tube (ETT) intubation was faster and less damaging to the airway when the Aintree intubating catheter was used in conjunction with a fiberoptic bronchoscope. To date there are no studies utilizing the King laryngeal tube (LT) for blind airway exchange were found.

Methods: This was a prospective crossover study. Participants were recruited from a group of active duty emergency department medical personnel participating in a cadaver training lab. Researchers pre-placed SGA devices in six cadavers with grade I/II airways. Participants attempted airway exchange with each SGA for 2 minutes. The order of SGA devices was alternated for each successive participant. Participants rated the ease or difficulty of placement for each SGA. Success of airway exchange was defined as proper placement of the ETT in the trachea and was confirmed by the same emergency medicine physician via direct laryngoscopy throughout the entire study.

Results: Forty-four emergency department personnel participated in the study. Pairwise McNemar's tests revealed a significantly higher success rate for the LMA unique (LMAU) compared with the King LT (p = 0.039) and a significantly higher success rate for the i-gel compared to both the LMAU (p = 0.007) and the King LT (p < 0.001). Pairwise McNemar's tests also indicated that failure due to placement errors was significantly less prevalent and failure due to running over time was significantly more prevalent with the King LT compared to the i-gel (p = 0.004) and the LMAU (p = 0.002). There was no significant relationship between blind airway exchange success rates and prior intubation experience.

Conclusion: Considering success rate, ease of use and price, the i-gel was found superior to the King LT and the LMAU for blind airway exchange with an ETT when using an Aintree intubating catheter as an introducer.