Differences in air ambulance patient mix demonstrated by physiologic scoring

Area of Science:

• Emergency Medicine
• Medical Transport Systems
• Clinical Outcomes Assessment

Background:

• Aeromedical transport is a critical component of emergency medical services.
• Justification for aeromedical transport is typically based on patient severity of illness or injury.
• Variability in patient acuity across different air transport programs requires investigation.

Purpose of the Study:

• To assess the detectability of patient severity differences in air transport programs.
• To evaluate the utility of established physiologic scoring systems in this context.
• To determine the proportion of critically ill patients transported by air medical services.

Main Methods:

• Prospective data collection on 1,868 consecutive patient transfer requests from six air medical services.
• Application of three established physiologic scores: Trauma Score, APACHE Score, and RAPS.
• Definition of critically ill based on strict physiologic criteria.

Main Results:

• Overall, 42.6% of patients met criteria for critical illness (range: 34.8%–53.3%).
• Patients transferred from inpatient units or with cardiac disease were less likely to be critically ill.
• Significant inter-program variability was observed in the percentage of critically ill patients transported.

Conclusions:

• Physiologic scoring systems may be valuable for comparing the performance of air ambulance programs.
• A substantial proportion of patients transported by air medical services may not meet strict criteria for critical illness.
• Further research is warranted to optimize patient selection criteria for aeromedical transport.