CHAPTER 18: Air Medical Transport

INTRODUCTION

The growing air medical transport sector represents a highly visible concentration of resources. A 2007 publication estimated that in the United States, 753 helicopters (and 150 dedicated fixed-wing aircraft) were in EMS service, providing about 3% of all ambulance transports.¹ By 2011, the Association of Air Medical Services (AAMS) placed the number of rotor-wing (ie, helicopter) transport vehicles at about 900. Individual helicopter EMS (HEMS) programs' mission profiles and crew configurations vary widely. Varying programs have varying mission breakdowns (as well as differing aircraft and crew configurations), but a typical US HEMS program performs 54% interfacility transports, 33% scene runs, and 13% “other” mission types (eg, neonatal, pediatric, transplant related).²

OBJECTIVES

• Discuss the utilization and integration of air medical services in field response.

• Discuss the unique role of air medical transport for interfacility transfers.

• Describe the physiologic changes and medical limitations associated with air medical transport.

• Describe the utilization of fixed-wing versus rotor-wing transport.

• Discuss different rotor-wing aircraft types and give specific examples.

• Discuss unique safety considerations.

• Describe operations for establishing an LZ and for safe landing/take-off of rotor-wing aircraft in the field and at the hospital.

• List governmental and professional agencies that set standards for ­aircraft and air medical operations.

• Discuss the licensure and certification implications of operations across state boundaries.

UTILIZATION AND INTEGRATION OF AIR MEDICAL SERVICES IN FIELD RESPONSE

While there is occasional utility in HEMS deployment for nontrauma ­situations (eg, time-critical diagnoses such as stroke),^5–6 most of the applicable use and evidence for scene response deals with HEMS dispatch for injured patients. The availability of rotor-wing response is variable throughout the country based on the location of air bases in relation to populations they serve (Figure 18-1).

EVIDENCE SUPPORTING INCORPORATION OF AIR MEDICAL ASSETS INTO SYSTEM SCENE RESPONSE

An independent 2007 review of all studies dating from the year 2000, ­conducted by the Institute of Health Economics for the Canadian health ministry in Alberta, concluded: “Overall, patients transported by ­helicopter showed a benefit in terms of survival, time interval to reach the healthcare facility, time interval to definite treatment, better results, or a benefit in general.”⁷ This finding was endorsed in a recent review of the worldwide HEMS scene response literature.⁸ Since the landmark 1983 JAMA paper from Baxt and Moody,⁹ which suggested roughly 50% ­mortality improvement with HEMS, the preponderance of subsequent evidence has identified lesser—but significant—outcomes improvement in the range of 20% to 30% better survival. ^11–15 As outlined elsewhere,^11–...