Interfacility helicopter ambulance transport of neurosurgical patients: observations, utilization, and outcomes from a quaternary level care hospital

Abstract

Background: The clinical benefit of helicopter transport over ground transportation for interfacility transport is unproven. We sought to determine actual practice patterns, utilization, and outcomes of patients undergoing interfacility transport for neurosurgical conditions.

Methodology/principal findings: We retrospectively examined all interfacility helicopter transfers to a single trauma center during 2008. We restricted our analysis to those transfers leading either to admission to the neurosurgical service or to formal consultation upon arrival. Major exclusion criteria included transport from the scene, death during transport, and transport to any area of the hospital other than the emergency department. The primary outcome was time interval to invasive intervention. Secondary outcomes were estimated ground transportation times from the referring hospital, admitting disposition, and discharge disposition. Of 526 candidate interfacility helicopter transfers to our emergency department in 2008, we identified 167 meeting study criteria. Seventy-five (45%) of these patients underwent neurosurgical intervention. The median time to neurosurgical intervention ranged from 1.0 to 117.8 hours, varying depending on the diagnosis. For 101 (60%) of the patients, estimated driving time from the referring institution was less than one hour. Four patients (2%) expired in the emergency department, and 34 patients (20%) were admitted to a non-ICU setting. Six patients were discharged home within 24 hours. For those admitted, in-hospital mortality was 28%.

Conclusions/significance: Many patients undergoing interfacility transfer for neurosurgical evaluation are inappropriately triaged to helicopter transport, as evidenced by actual times to intervention at the accepting institution and estimated ground transportation times from the referring institution. In a time when there is growing interest in health care cost containment, practitioners must exercise discretion in the selection of patients for air ambulance transport--particularly when it may not bear influence on clinical outcome. Neurosurgical evaluation via telemedicine may be one strategy for improving air transport triage.

Figure 1. Disposition of patients following interfacility helicopter transport.

The disposition of patients following helicopter transport varied among several locations in the hospital. A large proportion of patients were admitted to a non-ICU setting.

Figure 2. Estimated ground driving time for patients undergoing interfacility helicopter transport.

Estimated driving times were then calculated by using Google Maps software (Google Inc. Mountain View, CA USA), using exact street addresses of door-to-door emergency department transport. The majority of patients transported were estimated ≤80 minutes.

Figure 3. Median time to procedure by procedure.

The median times to intervention are presented (hours). Fiberoptic intracranial pressure monitors had the shortest interval at 1.0 hours, whereas spine fusions were 117.8 hours.

Figure 4. Operative versus non-operative management for selected diagnoses.

The distribution of management, dichotomized as “operative” or “non-operative” for selected diagnosis. The majority of spine fractures had no invasive intervention, whereas the majority of stroke patients underwent endovascular stroke therapy.

Figure 5. Discharge disposition for admitted patients following interfacility helicopter transport.

Patients that were admitted to the hospital were ultimately discharged to home, inpatient rehabilitation, or the morgue/hospice.