Air vs ground transport and outcome in trauma patients requiring urgent operative interventions.

OBJECTIVE: To study trauma patients requiring urgent operative interventions to determine whether transport mode was associated with outcome difference.
METHODS: Eligible patients were injured adults and children who presented over a 57-month period to the emergency department (ED) at the study hospital (annual ED census 36,000) after air or ground transport from trauma scenes or referring hospitals. Patients included were those whose ED lengths of stay were <60 minutes prior to transfer to an operating room. Data collected included injury severity score (ISS), ED and hospital lengths of stay, and mortality. Continuous data, which were not distributed normally, were analyzed using Wilcoxon nonparametric analysis. Categorical variables were analyzed using chi-square testing. Multivariate logistic regression was used to account for confounding variables and isolate the effects of transport mode on mortality. Alpha for all tests was set at 0.05.
RESULTS: 272 patients were eligible for study; 168 air medical and 104 ground transports. No between-group differences were found for ED length of stay, ISS, or mortality. A significantly longer hospital stay was found for air-transported patients. Subgroup analysis of patients with penetrating trauma and ISS of > or =25 revealed mortalities of 28% and 45% for air- and ground-transported patients, respectively; this difference was not statistically significant (p = 0.24), but the study had a power of only 22% to detect a difference at this magnitude.
CONCLUSION: This study failed to identify, but had insufficient power to rule out, outcome benefit to air medical transport in a subset of trauma patients requiring urgent operative interventions.