The 2022 (POCUS) World Conference featured speakers from across the globe and from many disciplines. Presenters and participants came to commemorate a shared value: innovation in the medical field. Point-of-care ultrasound (POCUS) is a leading example of that innovation. As keynote speaker Dr. Larry Istrail, M.D. pointed out, it has bridged the gap between science and science fiction. The handheld device has torn down a veil, and clinicians can now see what they once could only hear. It has empowered them to diagnose and treat patients more confidently.
During the conference, Dr. William Krebs, D.O., shared how POCUS has not only brought sonography to the bedside but to the skies as well. Even prior to medical school, Krebs had developed an interest in air medical transport. After attending medical school and obtaining a residency in emergency medicine, where he was able to practice as a flight physician and acquire his RDMS, he is now the medical director for Mercy Health Life Flight Network in Ohio. There, he educates flight physicians on the use of point-of-care ultrasound.
In his presentation, Dr. Krebs points out that patients cared for by the critical care transport team are often undifferentiated or possibly incorrectly identified by initial providers without access to POCUS. Throughout the four years that his team has utilized ultrasound, POCUS has confirmed or altered initial critical care management to benefit the patient.
Without access to ultrasound, many pathologies may be challenging to distinguish. However, POCUS has served in both hospital and pre-hospital settings as a tool to reveal key distinctions. Dr. Krebs presented multiple hypothetical cases in which imaging would provide additional insight beyond initial perceptions. Having accurate information about patient status as early as possible enables flight physicians to make rapid decisions about which hospital will offer the best treatment and to position the patient well in advance for a desirable outcome.
As he discussed these cases, Dr. Krebs also described the practical differences between POCUS usage in a helicopter ambulance and the hospital. He warned that the images he shared might be over- or under-gained. These adjustments in gain were intentional and necessary due to the setting and amount of light available during the scan. On sunny days, flight physicians must increase gain for visibility, versus when they need to decrease the gain on dark nights.
Dr. Krebs also explained that some traditional diagnostic practices are ineffective in the air due to helmets, headsets, and the deafening sound of helicopter rotors. In situations where, on the ground, paramedics would have been able to evaluate patient status with a stethoscope or by the sound of patients’ breath, his team must instead rely on the visual images provided by POCUS.
Altitude is an additional factor that helicopter paramedics must consider. According to Boyle’s Law, if volume increases, then pressure decreases and vice versa. Therefore, as the helicopter ascends and pressure drops, patients experience increased volume inside the chest cavity. This increases the risk of tension pneumothorax. Without ultrasound, paramedics must rely on late-stage symptoms such as jugular vein distention or hemodynamic collapse for a diagnosis. Unfortunately, once these signs arise, the patient has already begun to deteriorate. Ultrasound scans allow paramedics to act preemptively and prepare to place chest tubes before patient status declines.
Though the practical use of POCUS in the field differs slightly from that in the walls of a hospital, Dr. Krebs’ experience shows that the effects are the same. It allows physicians to rapidly and accurately diagnose and manage ailments before arriving at the emergency department. Dr. Istrail, in his keynote address, compared the tool to the fictional tricorder used by Dr. Leonard McCoy in Star Trek. The tricorder was a handheld device that could instantly diagnose patients, and while POCUS has not yet made it to the Final Frontier, it is taking us where no man has gone before.