The impact of aeromedical response to patients with moderate to severe traumatic brain injury.

STUDY OBJECTIVE Aeromedical crews offer an advanced level of practice and rapid transport to definitive care; however, their efficacy remains unproven. Previous studies have used relatively small sample sizes or have been unable to adequately control for the effect of other potentially influential variables. Here we explore the impact of aeromedical response in patients with moderate to severe traumatic brain injury. METHODS This was a retrospective analysis using our county trauma registry. All patients with head Abbreviated Injury Score of 3 or greater were included; interfacility transfers were excluded. The impact of aeromedical response was determined using logistic regression, adjusting for age, sex, mechanism, preadmission Glasgow Coma Scale score, head Abbreviated Injury Score, Injury Severity Score, and the presence of preadmission hypotension. Propensity scores were used to account for variability in selection of patients to undergo air versus ground transport. Patients with moderate and severe traumatic brain injury, as defined by head Abbreviated Injury Score and Glasgow Coma Scale score, were compared. Finally, aeromedical patients undergoing field intubation were compared with ground patients undergoing emergency department (ED) intubation. RESULTS A total of 10,314 patients meeting all inclusion and exclusion criteria and with complete data sets were identified and included 3,017 transported by aeromedical crews. Overall mortality was 25% in the air- and ground-transported cohorts, but outcomes were significantly better for the aeromedical patients when adjusted for age, sex, mechanism of injury, hypotension, Glasgow Coma Scale score, head Abbreviated Injury Score, and Injury Severity Score (adjusted odds ratio [OR] 1.90; 95% confidence interval [CI] 1.60 to 2.25; P<.0001). Good outcomes (discharge to home, jail, psychiatric facility, rehabilitation, or leaving against medical advice) were also higher in aeromedical patients (adjusted OR 1.36; 95% CI 1.18 to 1.58; P<.0001). The primary benefit appeared to be in more severely injured patients, as reflected by head Abbreviated Injury Score and Glasgow Coma Scale score. Improved survival was also observed for air-transported patients intubated in the field versus ground-transported patients given emergency intubation in the ED (adjusted OR 1.42; 95% CI 1.13 to 1.78; P<.001). CONCLUSION Here we analyze a large database of patients with moderate to severe traumatic brain injury. Aeromedical response appears to result in improved outcomes after adjustment for multiple influential factors in patients with moderate to severe traumatic brain injury. In addition, out-of-hospital intubation among air-transported patients resulted in better outcomes than ED intubation among ground-transported patients. Patients with more severe injuries appeared to derive the greatest benefit from aeromedical transport.

[1]  M. Rosko,et al.  A critical analysis of on-scene helicopter transport on survival in a statewide trauma system. , 1998, The Journal of trauma.

[2]  D. Davis,et al.  The impact of prehospital endotracheal intubation on outcome in moderate to severe traumatic brain injury. , 2005, The Journal of trauma.

[3]  J. Owen,et al.  One year's trauma mortality experience at Brooke Army Medical Center: is aeromedical transportation of trauma patients necessary? , 1999, Military medicine.

[4]  N. Weaver,et al.  Flight paramedic scope of practice: current level and breadth. , 1998, The Journal of emergency medicine.

[5]  W. Baxt,et al.  The impact of advanced prehospital emergency care on the mortality of severely brain-injured patients. , 1987, The Journal of trauma.

[6]  J. Sherck,et al.  The utility of helicopter transport of trauma patients from the injury scene in an urban trauma system. , 2002, The Journal of trauma.

[7]  R. Rutledge,et al.  A comparison of the association of helicopter and ground ambulance transport with the outcome of injury in trauma patients transported from the scene. , 1997, The Journal of trauma.

[8]  D. Scott,et al.  Role of an emergency helicopter transport service in rural trauma. , 1987, Archives of surgery.

[9]  S R Shackford,et al.  The effect of secondary insults on mortality and long-term disability after severe head injury in a rural region without a trauma system. , 1993, The Journal of trauma.

[10]  N Clay Mann,et al.  Injury mortality following the loss of air medical support for rural interhospital transport. , 2002, Academic emergency medicine : official journal of the Society for Academic Emergency Medicine.

[11]  T P Clemmer,et al.  Outcome, transport times, and costs of patients evacuated by helicopter versus fixed-wing aircraft. , 1990, The Western journal of medicine.

[12]  L. Jacobs,et al.  A comparison of ground paramedics and aeromedical treatment of severe blunt trauma patients. , 1990, Connecticut medicine.

[13]  W. Baxt,et al.  The impact of a physician as part of the aeromedical prehospital team in patients with blunt trauma. , 1987, JAMA.

[14]  C. Boyd,et al.  Emergency interhospital transport of the major trauma patient: air versus ground. , 1989, The Journal of trauma.

[15]  J. Richardson,et al.  Helicopter transport of trauma victims: does a physician make a difference? , 1991, The Journal of trauma.

[16]  Henry E. Wang,et al.  Out-of-hospital endotracheal intubation and outcome after traumatic brain injury. , 2004, Annals of emergency medicine.

[17]  T. Pittman,et al.  Early hypotension worsens neurological outcome in pediatric patients with moderately severe head trauma. , 1998, Journal of pediatric surgery.

[18]  S. Oppe,et al.  The effect of medical care by a helicopter trauma team on the probability of survival and the quality of life of hospitalised victims. , 2001, Accident; analysis and prevention.

[19]  K. A. Roberts.  Helicopter transport of trauma victims: Does a physician make a difference?: Hamman BL, Cue JI, Miller FB, et al J Trauma 1991; 31: 490–494 Apr 1991 , 1991 .

[20]  V. Wills,et al.  Use of an ambulance-based helicopter retrieval service. , 2000, The Australian and New Zealand journal of surgery.

[21]  D. Davis,et al.  The use of quantitative end-tidal capnometry to avoid inadvertent severe hyperventilation in patients with head injury after paramedic rapid sequence intubation. , 2004, The Journal of trauma.

[22]  F. Pigula,et al.  The effect of hypotension and hypoxia on children with severe head injuries. , 1993, Journal of pediatric surgery.

[23]  G. Nardi,et al.  Impact of emergency medical helicopter service on mortality for trauma in north-east Italy. A regional prospective audit. , 1994, European journal of emergency medicine : official journal of the European Society for Emergency Medicine.

[24]  Thomas M Scalea,et al.  Endotracheal intubation in the field does not improve outcome in trauma patients who present without an acutely lethal traumatic brain injury. , 2003, The Journal of trauma.

[25]  B. Munford,et al.  Air medical scene response to blunt trauma: effect on early survival , 1998, The Medical journal of Australia.

[26]  D. Davis,et al.  Air medical transport of severely head-injured patients undergoing paramedic rapid sequence intubation. , 2004, Air medical journal.

[27]  B. Rowe,et al.  Analysis of prehospital transport of head-injured patients after consolidation of neurosurgery resources. , 2002, The Journal of trauma.

[28]  S J Stratton,et al.  Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: a controlled clinical trial. , 2000, JAMA.

[29]  David B Hoyt,et al.  The effect of paramedic rapid sequence intubation on outcome in patients with severe traumatic brain injury. , 2003, The Journal of trauma.

[30]  Hospital-based rotorcraft aeromedical emergency care services and trauma mortality: a multicenter study. , 1985 .

[31]  L. Jacobs,et al.  Helicopter air medical transport: ten-year outcomes for trauma patients in a New England program. , 1999, Connecticut medicine.

[32]  P. Celli,et al.  Severe head trauma. Review of the factors influencing the prognosis. , 1997, Minerva chirurgica.

[33]  G S Georgiade,et al.  Factors Improving Survival in Multisystem Trauma Patients , 1988, Annals of surgery.

[34]  P. Austin,et al.  A literature review of the prehospital use of neuromuscular blocking agents by air medical personnel to facilitate endotracheal intubation. , 2000, Air medical journal.

[35]  A. Dietrich,et al.  Effective use of the air ambulance for pediatric trauma. , 2004, The Journal of trauma.

[36]  P. Kearney,et al.  Outcome of patients with blunt trauma transferred after diagnostic or treatment procedures or four-hour delay. , 1991, Annals of emergency medicine.

[37]  T. Coats,et al.  Interpretation of the Ws statistic: application to an integrated trauma system. , 1997, The Journal of trauma.

[38]  L. Jacobs,et al.  Impact of pre-trauma center care on length of stay and hospital charges. , 1989, The Journal of trauma.

[39]  E. Ruokonen,et al.  Paramedic helicopter emergency service in rural Finland – do benefits justify the cost? , 2002, Acta anaesthesiologica Scandinavica.

[40]  P. Suter,et al.  Helicopter mountain rescue of patients with head injury and/or multiple injuries in southern Switzerland 1980-1990. , 1993, Injury.

[41]  D. Demetriades,et al.  Prehospital intubation in patients with severe head injury. , 2000, The Journal of trauma.

[42]  J. Bernstein.  A comparison of ground paramedics and aeromedical treatment of severe blunt trauma patients: Schwartz RJ, Jacobs LM, Juda RJ Conn Med 54: 660–662 Dec 1990 , 1991 .

[43]  D. Davis,et al.  Auto launch/early activation: a survey of AAMS members and literature review. , 2005, Air medical journal.

[44]  R. O’Connor,et al.  F AILED P REHOSPITAL I NTUBATIONS : A N A NALYSIS OF E MERGENCY D EPARTMENT C OURSES AND O UTCOMES , 2001, Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors.

[45]  H. Zwipp,et al.  Impact of helicopter transport and hospital level on mortality of polytrauma patients. , 2004, The Journal of trauma.

[46]  Schwartz Rj,et al.  A comparison of ground paramedics and aeromedical treatment of severe blunt trauma patients. , 1990 .

[47]  W G Baxt,et al.  The impact of a rotorcraft aeromedical emergency care service on trauma mortality. , 1983, JAMA.

[48]  R. Falcone,et al.  Air medical transport of the injured patient: scene versus referring hospital. , 1998, Air medical journal.

[49]  A. Localio,et al.  Cost-effectiveness analysis of helicopter EMS for trauma patients. , 1997, Annals of emergency medicine.

[50]  Steven E Wolf,et al.  Impact of discontinuing a hospital-based air ambulance service on trauma patient outcomes. , 2002, The Journal of trauma.

[51]  G. Nardi,et al.  Effects of 2 patterns of prehospital care on the outcome of patients with severe head injury. , 2001, Archives of surgery.

[52]  J. Nicholl,et al.  The Cost and Effectiveness of the London Helicopter Emergency Medical Service , 1996, Journal of health services research & policy.

[53]  M A Foulkes,et al.  The role of secondary brain injury in determining outcome from severe head injury. , 1993, The Journal of trauma.

[54]  D. Davis,et al.  The impact of hypoxia and hyperventilation on outcome after paramedic rapid sequence intubation of severely head-injured patients. , 2004, The Journal of trauma.

[55]  N. Stocchetti,et al.  Hypoxemia and arterial hypotension at the accident scene in head injury. , 1996, The Journal of trauma.

[56]  P. Cameron,et al.  Helicopter retrieval of primary trauma patients by a paramedic helicopter service. , 1993, The Australian and New Zealand journal of surgery.

[57]  M. Eckstein,et al.  Effect of prehospital advanced life support on outcomes of major trauma patients. , 2000, The Journal of trauma.

[58]  D. Greenhalgh,et al.  Cost-effective use of helicopters for the transportation of patients with burn injuries. , 2000, The Journal of burn care & rehabilitation.

[59]  C. Cocanour,et al.  Are scene flights for penetrating trauma justified? , 1997, The Journal of trauma.

[60]  W. Baxt,et al.  The differential survival of trauma patients. , 1987, The Journal of trauma.

[61]  H Tscherne,et al.  On-scene helicopter transport of patients with multiple injuries--comparison of a German and an American system. , 1992, The Journal of trauma.

[62]  J. Nicholl,et al.  Effects of London helicopter emergency medical service on survival after trauma , 1995, BMJ.

[63]  W. Kerr,et al.  Differences in Mortality Rates Among Trauma Patients Transported by Helicopter and Ambulance in Maryland , 1999, Prehospital and Disaster Medicine.

[64]  S. Wedel,et al.  Helicopter transport and blunt trauma mortality: a multicenter trial. , 2002, The Journal of trauma.

[65]  C. Gotschall,et al.  Helicopter transport of injured children: system effectiveness and triage criteria. , 1996, Journal of pediatric surgery.

[66]  D. Hoyt,et al.  Rapid sequence intubation in the field versus hospital in trauma patients. , 2000, The Journal of emergency medicine.

[67]  J P Smith,et al.  The urban paramedic's scope of practice. , 1985, JAMA.

[68]  A. Garner,et al.  Addition of physicians to paramedic helicopter services decreases blunt trauma mortality. , 1999, The Australian and New Zealand journal of surgery.