Point-of-Care Ultrasound in Austere Environments

To The Editor:

Point-of-care ultrasound (POCUS) is an important tool that anesthesiologists, emergency physicians, trauma surgeons, and paramedics use to enhance patient care. ¹ POCUS has been used extensively in the prehospital, emergency department, and perioperative settings. ² We would like to demonstrate the combination of small wireless ultrasound devices with smart glasses to perform POCUS in austere environments. Austere environments typically involve limited medical resources. Patients in austere environments generally require lengthy transportation to definitive medical care facilities.

The ultrasound (GE Vscan Air, GE Healthcare, Chicago, IL) and smart glasses (Epson Moverio BT-40s, Seiko Epson Corp, Suwa, Nagano, Japan) are lightweight, very portable, and do not interfere with aircraft flight, including flight by aviators using night vision glasses. The night vision system amplifies ambient light. Light emission from ultrasound screens can cause the night vision to have a “white out” effect. When used with the GE Vscan Air, the glasses project a high-definition binocular image with a resolution of 1920×1080 pixels. This resolution is a great improvement compared with that of other portable ultrasound devices used in austere environments, such as the Sonosite M Turbo (Fujifilm Sonosite Inc, Bothell, WA), with a resolution of 800×600 pixels. ³ The combination of the glasses and ultrasound can replace the stethoscope for evaluation of the heart and lungs in flight. This is necessary because the noise of the aircraft makes a stethoscope useless. The glasses and ultrasound combination can also be used for ultrasound-guided IV access, regional anesthesia, and other procedures. Previous work with head-mounted displays, such as smart glasses, has demonstrated enhanced ergonomics, improved ability to detect changes in patient status, and enhanced performance of ultrasound-guided procedures ^{4 -6} compared with screen displays. This combination does not require special equipment and can be configured with off-the-shelf equipment. The ultrasound connects with a point-to-point WiFi connection and does not require an independent network to function.

In aeromedical evacuation, rapid diagnosis of pneumothorax can be critical because of atmospheric pressure changes associated with flight. This can be easily accomplished with POCUS. Many additional uses of POCUS can provide significant diagnostic and therapeutic benefit, including assessment of cardiac function, hemorrhage, volume status, and pulmonary status. ^{7 -9} The ability to assess these critical functions in a prehospital setting may enhance patient care and survivability of injuries. ¹⁰

In this demonstration of wireless ultrasound, the flight surgeon is able to perform POCUS while using smart glasses on this UH-1Y helicopter (Figure 1). In austere environments, the small size and high portability of the POCUS system with smart glasses increase the utility of the system compared with using the screen. Continued training of clinicians in the use of POCUS may enhance healthcare delivery outside the hospital setting.

Figure 1

Demonstration of the use of portable ultrasound with smart glasses on a UH-1Y aircraft. The patient’s chest is fully exposed for demonstration purposes. This does not represent typical practice for aeromedical evacuation.