Accuracy of tactile bougie use in infrequent intubators: a cadaveric airway study

When difficulty with laryngoscopy is encountered, confirmation of endotracheal access can be confirmed using the tactile feedback (i.e., tracheal clicks) of a tracheal tube introducer (bougie). There is anecdotal evidence that a bougie placed in the esophagus may have a unique, tactile "boggy" resistance. In this study, we aimed to elucidate the sensitivity and specificity of clicks and boggy resistance for infrequent airway providers in cadaveric airways.

We conducted a prospective observational study using descriptive statistics to examine the diagnostic accuracy of clicks and boggy resistance for bougies placed in cadaveric airways. We recruited prehospital providers from within Atlantic Canada who then underwent a brief formal training protocol. Cadavers were equipped with a static laryngoscope and bougie (placed either in the trachea or esophagus). Each participant, blinded to bougie placement, was then tested on two separate cadavers and asked whether they felt clicks and/or boggy resistance.

Thirty-seven paramedics participated in the study (32 advanced care paramedics, five critical care paramedics) and were randomized to perform 74 bougie assessments on cadaveric airways. For tracheal clicks, we calculated an overall sensitivity of 86% (95% confidence interval [CI], 75 to 98) and an overall specificity of 81% (95% CI, 68 to 94). Sensitivity for the esophageal boggy resistance test was 78% (95% CI, 65 to 92) while specificity was 86% (95% CI, 75 to 98).

Following a brief training session, prehospital providers who intubate infrequently seemed to show a relatively high degree of accuracy using tracheal clicks and esophageal boggy resistance to confirm bougie placement in cadaveric airways.