The effect of acute psychologic and physiologic stress on tactile bougie use: a cadaveric airway study

When difficulty with laryngoscopy is encountered, successful tracheal access can be indicated by the tactile feedback afforded by an advancing tracheal tube introducer ("bougie"). However, there is evidence that when providers experience psychologic and physiologic stress, their cognitive and motor abilities deteriorate. In this study, we used human cadaveric airways to examine the effect of stress on the accuracy of tactile feedback interpretation when infrequent airway providers use the bougie.

This was a partially-blinded, prospective, randomized, observational study. Paramedics were recruited, underwent a brief training protocol, and were then tested during four scenarios, two of which included stressful conditions. Our primary objective was to determine whether stress significantly affected the accuracy of tactile feedback interpretation in determining tracheal vs. esophageal bougie placement in a Cormack-Lehane Grade 3a situation. Secondary outcomes included providers' confidence in their assessments, their subjective stress level, and the time taken to make a decision.

Thirty-seven paramedics were randomized to complete 146 bougie assessments on cadaveric airways (74 under stressful conditions, and 72 under non-stressful conditions). Participants were significantly less accurate in determining the correct bougie location under stressful conditions, with an associated OR of 0.31 (95% CI [0.14, 0.68], p = .003).

The induction of psychologic and physiologic stress significantly decreased the accuracy of interpreting tactile feedback from a bougie in cadaveric airways by prehospital providers who intubate infrequently. Our data also suggests that although participants were less accurate during the stressful scenarios, they did not report being less confident in their assessments.