Fig. 1

Patient flow chart and grouping. Patients in the study were separated into 2 groups. Flight group (FG) patients were intubated during the flight; ground group (GG) patients were intubated on the ground prior to takeoff. The HEMS system receives a dispatch request from a public EMS, then takes off from the hospital and lands at the rendezvous point (RP). In some cases, the HEMS lands at the scene. Generally, at the RP, the HEMS staff make contact with the patient transported by the ground ambulance, treat the patient, then transport the patient to the hospital. If the HEMS team reaches the RP before ground EMS, the HEMS staff may respond to the scene. EMS: emergency medical service, HEMS: helicopter emergency medical service