Association between glottis screen location and intubation difficulty: a retrospective video laryngoscopy study

Area of Science:

• Emergency Medicine
• Anesthesiology
• Airway Management

Background:

• Difficult intubations can occur unexpectedly in emergency settings.
• Traditional glottic view scoring may not apply to video laryngoscopy.
• Video laryngoscopy allows clear glottis location definition on screen.

Purpose of the Study:

• To investigate the relationship between glottis screen location during video laryngoscopy and intubation success.
• To determine if glottis location predicts first-attempt intubation success and timing.

Main Methods:

• Retrospective analysis of 209 adult intubations using C-MAC video laryngoscope.
• Categorized vocal cord screen location as upper or lower based on arytenoid cartilage position.
• Analyzed first-attempt intubation success within 90 seconds using Kaplan-Meier curves and Cox proportional hazard analysis.

Main Results:

• A higher arytenoid location was significantly associated with lower first-attempt intubation success (P < 0.001).
• Arytenoid location independently predicted successful intubation within 90 seconds (aHR 0.55).
• The upper location group had a 45% reduced chance of successful first-attempt intubation compared to the lower group.

Conclusions:

• A higher vocal cord screen location after blade engagement predicts reduced first-attempt intubation success.
• Assessing glottis location during video laryngoscopy is a quick method to anticipate intubation challenges.
• This simple indicator can aid emergency airway management.