Flying FAST—Can You Keep Up?
Abstract & Commentary
Source: Polk JD, et al. The "Airmedical F.A.S.T." for trauma patients—The initial report of a novel application for sonography. Aviat Space Environ Med 2001;72:432-436.
The Focused Abdominal Sonogram for Trauma (FAST) has become an important tool for the evaluation of the trauma patient. The authors attempt to determine if the technology is applicable in the environment of helicopter medical evaluation. Two flight surgeons flew on board Sikorsky S-76 medical evacuation helicopters and used a Aloka SSD-500 portable ultrasound unit with a Sony UP 890 MD printer attached. The physicians underwent a one-week didactic course and sufficient clinical exposure at an outside facility with an established program in Emergency Medicine Bedside Ultrasound. The established goal for training was 50 FAST exams with five or more positive studies.
There were 100 patients enrolled in the study. Of those, 16 were excluded—eight for excessive body weight, six for hemodynamic instability requiring the physician to perform other clinical interventions, and two for machine unavailability. Of the 84 studies analyzed, four were penetrating trauma patients. There were 13 true positives and three false negatives, leading to a sensitivity of 81%. True negatives accounted for 68 patients. There were no false positives, giving a specificity of 100%. The negative predictive value was 96%. The accuracy was 96%. CT scan identified all three false-negative exams. One false negative was interpreted as negative both by radiology and the flight surgeon within 15 minutes of injury. The CT later revealed 200-300 mLs of hemoperitoneum. All patients who were too hemodynamically unstable to permit the physician sufficient time to complete a FAST exam had hemoperitoneum. The authors conclude that the FAST exam can be obtained in flight with similar quality and consistency as is currently obtained in the emergency department. They suggest that this technology may challenge traditional algorithms for prehospital care.
Comment by Richard J. Hamilton, MD, FAAEM, ABMT
It was only about 10 years ago that emergency physicians were arguing with anesthesiologists about whether they safely could use paralytic agents for rapid sequence intubation. All the while, flight nurses were paralyzing and intubating patients in the backs of helicopters without the slightest problem. Ultrasound is becoming the next dividing line between the "haves" and the "have nots" in EM. Already, the Residency Review Committee for Emergency Medicine is making ultrasound training a requirement for all programs. Significant numbers of current graduates of EM programs are proficient in ultrasound by virtue of training in this technology and are looking for jobs with a meaningful ultrasound presence in their practice. The portable ultrasound machine is an absolutely perfect match for remote medical care and medical evacuation. Remember the lessons of the past and don’t let the future of EM pass you by.