Helicopter emergency medical services utilization for winter resort injuries

Helicopter and ground emergency medical services (EMS) units are frequently called to transport patients from winter resorts to area trauma centers.

The purpose of this study was to examine helicopter EMS (HEMS) utilization for such patients, and to investigate out-of-hospital clinical variables that might help providers determine the most appropriate utilization of HEMS.

The study included patients aged ≥ 12 years who were transported by ground EMS (GEMS) or HEMS to a regional trauma center with an acute injury sustained at a winter resort. The decision to transport via HEMS was based on field provider judgment. Injury information was prospectively obtained and combined with emergency department (ED) and hospital data abstracted from trauma registry and hospital records. For the purpose of this study, appropriate HEMS utilization was defined according to two different schemes. Limited utilization of HEMS was defined as the need for an emergent ED or out-of-hospital intervention (intubation, chest tube or needle thoracostomy, central line placement, or cardiopulmonary resuscitation). Expanded utilization of HEMS was defined as the need for an emergent intervention and/or an Injury Severity Score (ISS) ≥ 16 and/or need for emergent nonorthopedic surgery. Provider judgment alone was compared with results of recursive partitioning to predict the need for HEMS.

Of 815 patients enrolled between 2006 and 2009, 65 (8.0%) patients met the expanded criteria for appropriate HEMS utilization. Of these, 30 (46.2%) were transported by GEMS and 35 (53.8%) were transported by HEMS. Twenty-seven of the 65 patients (41.5%) required an emergent ED or out-of-hospital intervention. Activation of HEMS by out-of-hospital providers was (at best) 55.6% sensitive and 89.1% specific (85.2% overtriage rate) for predicting the need for an emergent out-of-hospital or ED intervention. Recursive partitioning, using a Glasgow Coma Scale score (GCS) ≤ 13 or pulse oximetry value <89%, was superior to provider judgment in predicting the need for an emergent procedure (57.9% sensitive, 98.6% specific, 45% overtriage rate).

Use of a simple prediction rule was superior to provider judgment in predicting the need for an emergent ED or out-of-hospital procedure in patients injured at winter resorts. If validated, this rule may be a resource to help out-of-hospital providers decide when to activate HEMS in these unique areas.