Waveform capnography: an alternative to physician gestalt in determining optimal intubating conditions after administration of paralytic agents

Purpose: We sought to evaluate the utility of waveform capnography (WC) in detecting paralysis, by using apnoea as a surrogate determinant, as compared with clinical gestalt during rapid sequence intubation. Additionally, we sought to determine if this improves the time to intubation and first pass success rates through more consistent and expedient means of detecting optimal intubating conditions (ie, paralysis).

Methods: A prospective observational cohort study of consecutively enrolled patients was conducted from April to June 2016 at an academic, urban, level 1 trauma centre in New York City. Nasal cannula WC was used to determine the presence of apnoea as a surrogate measure of paralysis versus physician gestalt (ie, blink test, mandible relaxation, and so on).

Results: One hundred patients were enrolled (50 in the WC group and 50 in the gestalt group). There were higher proportions of failure to determine optimal intubating conditions (ie, paralysis) in the gestalt group (32%, n=16) versus the WC group (6%, n=3), absolute difference 26, 95% CI 10 to 40. Time to intubation was longer in the gestalt group versus the WC group (136 seconds vs 116 seconds, absolute difference 20 seconds 95% CI 14 to 26). First pass success rates were higher in the WC group verses the gestalt group (92%, 95% CI 85 to 97 vs 88%, 95% CI 88 to 95, absolute difference 4%, 95% CI 1 to 8).

Conclusion: These preliminary results demonstrate WC may be a useful objective measure to determine the presence of paralysis and optimal in tubating conditions in RSI.