Drug-assisted effects on protective airway reflexes during out-of-hospital endotracheal intubation (preliminary report).

Objective: Out-of-hospital rescuers often use drug-assisted intubation (DAI) to facilitate endotracheal intubation (ETI) of nonarrest patients. However, the relationship between the ablation of individual protective airway reflexes and resulting DAI success has not been defined. We sought to describe the relationship between the depression or ablation of protective airway reflexes and DAI success.

Methods: We analyzed data from a prospective multicenter trial. Rescuers from 42 emergency medical services systems reported clinical ETI data using standardized reporting forms. We analyzed the subset receiving sedative and/or neuromuscular blocking agents to facilitate ETI. We defined successful ETI as intratracheal placement of the endotracheal tube on the last ETI attempt. Rescuers reported the presence and ablation of six protective airway reflexes, including the presence of a gag, trismus, inadequate relaxation, combativeness, laryngospasm, and seizure/myoclonus. We examined the relationship between protective reflex ablation and DAI success.

Results: Of 1,953 ETIs, 208 (10.7%) used DAI (128 sedation only, 80 neuromuscular blocking agents/rapid sequence intubation). Successful DAI was associated with ablation of gag reflex (odds ratio [OR], 12.7; 95% confidence interval [CI] 3.7 to 46.2), clenched jaw/trismus (OR, 54.4; 95% CI, 11.1 to 292.4), inadequate relaxation (OR, 16.3; 95% CI, 3.7 to 96.4), and combativeness (OR, 10.2; 95% CI, 1.5 to 76.8). Successful DAI was associated with the total number of ablated protective reflexes (p < 0.001).

Conclusions: The ablation of selected and the total number of protective airway reflexes was associated with DAI success. Successful ablation of protective airway reflexes should be considered when attempting to characterize DAI performance or the effectiveness of specific drug facilitation regimens.