Impact of distance on mortality in trauma patients with an out-of-hospital intubation attempt

Michael T. Cudnik


01:OBJECTIVE: Out-of-hospital endotracheal intubation (OOH-ETI) has been associated with adverse outcomes; whether transport distance changes this relationship is unclear. We sought to determine whether patients injured farther from the hospital benefit more from OOH-ETI than those injured closer. METHODS: Retrospective cohort analysis of all trauma patients> 14 years transported to one of two Level I trauma centers and surviving to admission from January 2000-December 2003 ( 19 counties). Probabilistically linked geographical data were used to calculate transport distance. To adjust for the nonrandom selection of patients for OOH-ETI, we used a propensity score based on important clinical variables: prehospital physiologic measures, patient demographics, transport mode, mechanism, comorbidities, Abbreviated Injury Scale head injury, injury severity score, blood transfusion, major surgery. A propensity-adjusted multivariable logistic regression ( outcome=in-hospital mortality) with mode of transport was used to test the interaction between distance x OOH-ETI. We used fractional polynomials to assess non-linear relationships between distance and outcome and multiple imputation for missing values. RESULTS: 8.786 patients were included, of which 534 (6~1)) had OOH-ETI Patients with OOH-ETI had higher adjusted mortality (OR 2.06, 95%Cr 1.33-3.18), and there was a strong interaction between distance x OOH-ETI (p"'0.02). Patients with the shortest transport distances had the highest mortality (OR 3.98, 95%CI 2.08-7.60). Probability of mortality was higher with OOH -ETI across all distances and increased for patients closest to the hospital (no change for patients without OOH-ETI) CONCLUSIONS: Prehospital intubation is associated with an increase in mortality among trauma patients at all distances from the hospital. Patients with the shortest transport distances had the greatest mortality associated with OOI I-ETI. The event location and the ensuing distance to the receiving hospital arc yet another factor to consider when instituting and modifying OOH airway protocols.