Original ResearchThe Impact of Aeromedical Response to Patients With Moderate to Severe Traumatic Brain Injury
Introduction
Multiple factors have been demonstrated to affect outcome in traumatic brain injury, including those influenced by care received in the out-of-hospital environment.1, 2, 3, 4 Foremost among these factors include the avoidance of secondary insults, such as hypoxia and hypotension, and the identification of potential traumatic brain injury and subsequent triage to a facility capable of definitive care,5, 6, 7, 8, 9, 10 which has led to the development of emergency medical services (EMS) systems that provide a rapid response to major trauma victims and can offer a variety of therapeutic interventions, such as endotracheal intubation and intravenous fluids, as well as rapid transport to a designated receiving facility.11, 12
Helicopters are used in many systems to respond to major trauma victims, with 3 theoretical therapeutic advantages: (1) rapid transport to a designated receiving facility when ground transport is unavailable or would lead to inordinate delays, (2) response by advanced practitioners with an expanded scope of practice to optimize early care, and (3) response by crews with greater experience managing critically injured patients. Establishing the efficacy of aeromedical response to major trauma victims has been challenging, however, because controlled trials are difficult and may not be ethical in systems with established aeromedical presence, which has resulted in descriptive, pseudoexperimental (eg, revised trauma score and injury severity score [TRISS]), or cohort analyses that have generally supported the use of aeromedical resources but may have been influenced by selection bias.13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52 Several large, registry-based analyses have been performed that attempt to control for various factors that influence outcome in major trauma victims; however, results have been inconsistent, and a complete set of data available for regression modeling has not been available.33, 38, 46
Here we perform an analysis using a large database of head-injured patients from the same EMS system, including multiple factors that affect outcome in traumatic brain injury. The following specific issues were addressed: (1) the impact of air medical response in moderate to severe traumatic brain injury, (2) identification of patients who benefit most from aeromedical transport, and (3) the relative efficacy of field intubation in patients transported by air versus emergency department (ED) intubation in patients transported by ground.
Section snippets
Study Design
This was a retrospective analysis using data from the San Diego County Trauma Registry. Waiver of informed consent was granted by our investigational review board. Approval for this project was obtained from each of the 5 adult trauma centers.
San Diego County has a population of about 3 million in an area of more than 4,000 square miles. A minimum of 2 paramedics respond to all adult major trauma victims, who are transported to 1 of 5 designated trauma centers, all of which are Level I or II
Results
A total of 13,625 patients were identified with a head Abbreviated Injury Score of 3 or greater; the overall mortality in this group was 23%. A total of 3,313 patients were excluded from this analysis, which included 1,398 patients who underwent interfacility transport by helicopter (mortality 14%) and 1,913 patients with incomplete data (mortality 18%).
The remaining 10,314 patients were included in this analysis, with an overall mortality of 25%. Demographic and clinical variables for all
Limitations
There are several limitations to the analysis that must be considered when these data are interpreted. Although our registry is subject to several layers of quality-assurance oversight, it is ultimately limited by the ability of out-of-hospital providers to accurately collect and communicate these data. In addition, we selected patients for inclusion based on head Abbreviated Injury Score score, which is calculated after admission based on radiographic, operative, and autopsy findings that are
Discussion
Defining the optimal role of helicopters in an EMS or trauma system is difficult for a variety of reasons. Performing a randomized, controlled trial to define the efficacy of aeromedical response would be logistically challenging, prohibitively expensive, and ethically suspect in a system with established aeromedical presence. Thus, it is not surprising that so many previous studies have relied on suboptimal methodologies or had limited generalizability outside of their local EMS system.13, 14,
References (70)
- et al.
Early hypotension worsens neurological outcome in pediatric patients with moderately severe head trauma
J Pediatr Surg
(1998) - et al.
Outcome of patients with blunt trauma transferred after diagnostic or treatment procedures or four-hour delay
Ann Emerg Med
(1991) - et al.
Air medical transport of the injured patient: scene versus referring hospital
Air Med J
(1998) - et al.
Flight paramedic scope of practice: current level and breadth
J Emerg Med
(1998) - et al.
Hospital-based rotorcraft aeromedical emergency care services and trauma mortality: a multicenter study
Ann Emerg Med
(1985) - et al.
Helicopter mountain rescue of patients with head injury and/or multiple injuries in southern Switzerland 1980-1990
Injury
(1993) - et al.
Helicopter transport of injured children: system effectiveness and triage criteria
J Pediatr Surg
(1996) - 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
Accid Anal Prev
(2001) - et al.
Cost-effectiveness analysis of helicopter EMS for trauma patients
Ann Emerg Med
(1997) - et al.
Failed prehospital intubations: an analysis of emergency department courses and outcomes
Prehosp Emerg Care
(2001)
Out-of-hospital endotracheal intubation and outcome after traumatic brain injury
Ann Emerg Med
Rapid sequence intubation in the field versus hospital in trauma patients
J Emerg Med
A literature review of the prehospital use of neuromuscular blocking agents by air medical personnel to facilitate endotracheal intubation
Air Med J
Aeromedical transport of severely head-injured patients undergoing paramedic rapid sequence intubation
Air Med J
Auto launch/early activation: a survey of AAMS members and literature review
Air Med J
The role of secondary brain injury in determining outcome from severe head injury
J Trauma
The effect of hypotension and hypoxia on children with severe head injuries
J Pediatr Surg
Hypoxemia and arterial hypotension at the accident scene in head injury
J Trauma
Differences in mortality rates among trauma patients transported by helicopter and ambulance in Maryland
Prehosp Disaster Med
Neurotrauma and trauma systems
New Horiz
The effect of secondary insults on mortality and long-term disability after severe head injury in a rural region without a trauma system
J Trauma
Analysis of prehospital transport of head-injured patients after consolidation of neurosurgery resources
J Trauma
The urban paramedic's scope of practice
JAMA
The impact of a rotorcraft aeromedical emergency care service on trauma mortality
JAMA
The differential survival of trauma patients
J Trauma
The impact of a physician as part of the aeromedical prehospital team in patients with blunt trauma
JAMA
The impact of advanced prehospital emergency care on the mortality of severely brain-injured patients
J Trauma
Urban helicopter response to the scene of injury
J Trauma
Role of an emergency helicopter transport service in rural trauma
Arch Surg
Effect of helicopter transport of trauma victims on survival in an urban trauma center
J Trauma
Impact of pre-trauma center care on length of stay and hospital charges
J Trauma
A comparison of ground paramedics and aeromedical treatment of severe blunt trauma patients
Conn Med
Critical care helicopter service: evaluation of prehospital utilization in trauma care
Conn Med
Factors improving survival in multisystem trauma patients
Ann Surg
Emergency interhospital transport of the major trauma patient: air versus ground
J Trauma
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Supervising editor: William G. Barsan, MD
Author contributions: DD, JS, CB, GV, MS, and DH conceived the study design. Data collection was completed by DD, MS, FK, ABE, TV, and DH. Data analysis was done by DD, JP, JS, CB, GV and AS. All authors contributed substantially to manuscript preparation. DD takes responsibility for the paper as a whole.
Funding and support: The authors report this study did not receive any outside funding or support.
Presented at Air Medical Transport Conference, 2004, Cincinnati, OH.
Reprints not available from these authors.