Predictors of Definitive Airway Sans Hypoxia/Hypotension on First Attempt (DASH-1A) Success in Traumatically Injured Patients Undergoing Prehospital Intubation

Abstract

Background: Prehospital intubation success is routinely treated as a dichotomous outcome based on an endotracheal tube passing through vocal cords regardless of number of attempts or occurrence of hypoxia, or hypotension, which are associated with worse outcomes. We explore patient, provider, and procedure-related variables associated with successful definitive airway sans hypoxia/hypotension on first attempt (DASH-1A) in traumatically injured subjects undergoing endotracheal intubation at the scene of injury by a helicopter EMS system.Methods: This single-center retrospective chart review included patients with traumatic injuries and at least one attempted intubation by helicopter EMS at the scene of injury. Demographic and clinical variables were tested for association with DASH-1A and overall first-attempt success using univariate comparisons and multivariable logistic regression to produce adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Purposeful backwards stepwise elimination was used to develop logistic regression models for outcomes. Initial inclusion of covariates in multivariable models was based on clinical judgement, known or suspected risk factors and confounders for intubation success, and univariate associations.Results: Of 419 subjects screened, 263 met inclusion criteria. Median age was 34 years and the majority of subjects were Caucasian (95%), male (76%), and suffered blunt trauma (90%). The endotracheal tube was successfully placed on the first attempt in 198 (75.3%) of patients, but only 142 (55.3%) had a successful DASH-1A, and overall, 246 (94%) had an endotracheal tube passed successfully before hospital arrival. Factors significantly associated with successful DASH-1A were no ground EMS intubation attempt prior to arrival [aOR 2.2 (CI 1.0–4.9)], lack of airway secretions/blood [1.9 (1.0–3.4)], Cormack-Lehane Score of I and II [12.3 (4.5–33.2) & 3.2 (1.2–9.1), respectively], and bougie use [5.4 (1.8–15.8)]. For endotracheal tube passing only, the following were significantly associated with first pass success: grade of view I and II [aORs 87.3 (CI 25.8–295.7) & 6.8 (2.3–19.5), respectively], lack of secretions/blood [4.9 (2.1–11.2), bougie use [7.8 (2.3–26.3)], direct laryngoscopy [5.1 (1.5–17.0)] and not using apneic oxygenation through a nasal cannula [2.5 (1.1–5.6)].Conclusion: In our helicopter EMS system, successful endotracheal intubation on the first attempt and without an episode of hypoxia was associated with no ground EMS intubation attempt prior to flight crew arrival, lack of airway secretions/blood, Cormack-Lehane Score, and bougie use.