Patients with Traumatic Injury Transported by Critical Care Air Transport Teams (CCATT): The Influence of Altitude and Oxygenation During Transport

Background: During previous military conflicts, the US Air Force Critical Care Air Transport Teams (CCATTs) transported critical patients out of theater to Landstuhl Regional Medical Center (LRMC) with cabin pressures equivalent to an altitude of 5,000 to8,000 feet. Reduced barometric pressure is associated with decreased partial pressure of oxygen, which may contribute to hypoxia; and gas expansion, which may lead to trapped air in body cavities. Other in-flight stressors include acceleration, low humidity, thermal instability, vibration, and noise. These stressors may lead to secondary injuries or exacerbation of initial injuries. In order to avoid this theoretical risk, in theater medical providers, such as validating flight surgeons (VFSs), are tasked with determining if cabin altitude restrictions (CAR) to 4,000 6,000 feet should be prescribed for individual patients. Medical evacuation with CAR is not without risks. There is increased risk of turbulence and structural stress on the aircraft. Potential exposure to mountainous terrain, inclement weather, increased flight duration, and increased fuel consumption are all considerations associated with cabin altitude restriction. These operational concerns may contribute to an organizational resistance to the prescription of CAR. Thus, the prescription of CAR must weigh potential benefits to the patient with potential operational risks as described above.