Faster on-scene times associated with decreased mortality in Helicopter Emergency Medical Services (HEMS) transported trauma patients

BACKGROUND: The ‘Golden Hour’ emphasizes the importance of rapidly providing definitive care to trauma patients. Dispatch time, defined as the time it takes the Helicopter Emergency Medical Service (HEMS) to dispatch from their base and reach the patient, and on-scene time, defined as the time spent with the patient prior to departure to a trauma center, can impact how quickly the patient will reach definitive care. We evaluated HEMS dispatch and on-scene times by investigating the survival rates among patients transported by air to a level 1 trauma center. We hypothesize that longer HEMS dispatch and on-scene times are associated with worse patient outcomes. METHODS: A retrospective, single institution analysis was performed on patients transported by HEMS. Inclusion criteria were air transported patients aged 18 years and above admitted to a level 1 trauma center from January 1, 2005 to January 1, 2015. Total dispatch time and on-scene times were divided into five incremental groups and mortality data were analyzed. Mortality was defined as death during initial hospital admission. A Pearson’s correlation was used to analyze relationship between dispatch times, on-scene times, and mortality. Simple binary logistic regression was used to run a multivariate analysis on confounding variables of Injury Severity Score (ISS), gender, age, and Glasgow Coma Scale. RESULTS: There was a strong positive linear correlation between HEMS on-scene time and mortality, R=0.962, p=0.038. Additionally, there was a positive trend between HEMS dispatch time and mortality. ISS was found to be a significant confounder of mortality in our cohort with on-scene times >20 min, with mortality increasing by 7.5% for every 0.1 increase in ISS score (p=0.01). CONCLUSION: Longer HEMS on-scene and dispatch times appeared to be associated with increased mortality in trauma patients. However, those with higher ISS require longer on-scene times, increasing mortality. Regardless, efforts should focus on reducing on-scene and dispatch times. LEVEL OF EVIDENCE AND STUDY TYPE: Level III; Therapeutic/Care Management.