Background: An important goal of emergency airway management is to complete endotracheal intubation (ETI) correctly, safely, and quickly, and repeated ETI attempts can increase patient morbidity and mortality. Clinical protocols limiting the number of ETI attempts may minimize harm, but this strategy also may reduce the frequency of successful ETI.
Objectives: To characterize the relationship between the number of out-of-hospital ETI attempts and ETI success.
Methods: This study used prospective, multicenter data from 42 emergency medical services agencies from an 18-month period. Out-of-hospital rescuers (paramedics, out-of-hospital nurses, and physicians) completed structured, closed-response data forms describing clinical methods, course, and outcomes for all ETIs. An ETI attempt was defined as an insertion of the laryngoscope blade. Rescuers identified ETI outcome (success or failure) for each attempt. The authors defined overall success as ETI outcome (success or failure) on the last attempt, examining cardiac arrest, conventional nonarrest, sedation-facilitated, and rapid-sequence ETI separately. Univariate odds ratios (ORs) were used to identify the number of ETI attempts in which the cumulative ETI success rate approached the overall ETI success rate.
Results: Complete data were available for 1,941 cases. More than 30% of patients received more than one ETI attempt. For 1,272 cardiac arrest ETIs, cumulative success for the first three attempts were 69.9%, 84.9%, and 89.9%; cumulative success approached overall success (91.8%) after three attempts (OR, 0.79; 95% confidence interval [CI] = 0.61 to 1.04). For 463 conventional non-arrest ETIs, cumulative success for the first three attempts were 57.6%, 69.2%, and 72.7%; cumulative success approached overall success (73.7%) after two attempts (OR, 0.95; 95% CI = 0.71 to 1.28). For 126 sedation-facilitated ETIs, cumulative success for the first three attempts were 44.4%, 62.7%, and 75.4%; cumulative success approached overall success (77.0%) after three attempts (OR, 0.92; 95% CI = 0.51 to 1.64). For 80 rapid-sequence ETI, cumulative ETI success for the first three attempts were 56.3%, 81.3%, and 91.3%; cumulative success approached overall success (96.3%) after three attempts (OR, 0.41; 95% CI = 0.10 to 1.65).
Conclusions: Out-of-hospital rescuers often require multiple attempts to accomplish ETI. A protocol limit of three attempts offers reasonable opportunity for accomplishing ETI within the constraints of the out-of-hospital environment.