title: Helicopter evacuation of trauma victims in Los Angeles: does it improve survival?
abstract: BACKGROUND
  The purpose of this study was to investigate the relationship between the method of transport after injury and survival among trauma patients admitted to a Level 1 trauma facility in Los Angeles, California.
  
  
  METHODS
  The trauma registry of LAC+USC Medical Center was reviewed to identify all injured patients evacuated by emergency medical service (EMS) from the injury scene from 1998 to 2007. The study population was divided into those who were airlifted (HEMS) and those who were transported by ground emergency medical service (GEMS) with transportation time that exceeded 30 minutes (GEMS > 30 minutes).
  
  
  RESULTS
  During the 10-year study period, 1,836 patients were airlifted (helicopters for emergency medical service (HEMS)) and 1,537 patients were ground transported (GEMS > 30 minutes). HEMS patients suffered more frequently a penetrating injury (19% vs. 11%, p < 0.001), presented more often hypotensive to the emergency department (4% vs. 1%, p < 0.001), had more frequently a Glasgow Coma Scale (GCS) < or = 8 (9% vs. 3%, p < 0.001) and required more often an intubation at the injury scene (1.6% vs. 0.4%, p < 0.001). However, the transportation time and the total prehospital time were significantly shorter for airlifted patients. After multivariable analysis, the difference in mortality between the two transport modalities was not significant (adjusted odds ratio (95% confidence interval, 0.72 (0.22, 2.35); p = 0.596).
  
  
  CONCLUSIONS
  In a metropolitan Los Angeles trauma system, EMS helicopter transportation of injured patients does not appear to improve overall adjusted survival after injury. There is however a potential benefit for severely injured subgroups of patients due to the shorter prehospital times.
authors: LAC+USC Medical Center, Division of Trauma Surgery and Surgical Critical Care, University of Southern California, 1200 North State Street, IPT, Room C4E100, Los Angeles, CA 90033, USA. peep.talving@karolinska.se
authors: Peep
authors: P
authors: Talving
authors: Pedro G R
authors: PG
authors: Teixeira
authors: Galinos
authors: G
authors: Barmparas
authors: Joseph
authors: J
authors: DuBose
authors: Kenji
authors: K
authors: Inaba
authors: Lydia
authors: L
authors: Lam
authors: Demetrios
authors: D
authors: Demetriades
mesh_terms: D000293:Adolescent; D000328:Adult; D017732:Air Ambulances; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D015141:Los Angeles; D008297:Male; D008875:Middle Aged; D012042:Registries; D016019:Survival Analysis; D014187:Transportation of Patients / Q000379:methods*; D014193:Trauma Centers; D014947:Wounds and Injuries / Q000401:mortality* / Q000628:therapy*; D055815:Young Adult