Trauma ultrasound feasibility during helicopter transport

Objective: To evaluate the feasibility of performing a standard four-view focused abdominal sonography for trauma (FAST) examination during helicopter transport using a hand-carried ultrasound machine. Methods: In this prospective observational study, actual and simulated trauma patients were evaluated using the SonoSite 180 ultrasound machine by two air transport programs serving Level I trauma centers. FAST examinations were performed in flight by emergency medicine faculty, residents, flight nurses, and ultrasound technologists, who rated the difficulty posed by various factors using Likert scales (0 = not difficult to 5 = impossible). BK 117, Bell 230, and BO 105 medical helicopters flew in all aviating modes. Pilots were queried regarding avionics variations throughout the flights. Results: Ten flight sonographers performed 21 FAST examinations on 14 patients (five actual, nine simulated). The median Likert value for each parameter was 0 except for patient position, which was 1 (somewhat difficult). Interquartile ranges were 0-0 for vibration, bedding, IV catheters, monitor cables, and ventilator; 0-0.5 for backboard straps; and 0-1 for sunlight, patient position, spider straps, gurney straps, and clothing. Mean examination duration was 3.0 minutes (range 1.5 to 5.5 minutes, SD 1.3). Pilots reported no effects on avionics in any flight mode. Conclusion: The FAST examination using the SonoSite 180 in flight was rated by 10 evaluators to be performed easily. Examinations were conducted quickly and did not interfere with helicopter avionics. This digital ultrasound machine is the first one small enough to be used in most medical helicopters.