Study Shows Feasibility of Portable Ultrasound to Examine Trauma Victims During Helicopter Transport

03/28/01    Portland, Ore.

A new study by emergency medicine researchers demonstrates that portable ultrasound devices can be used to assess the severity of some traumatic injuries in patients while being transported in an emergency medical helicopter. According to the study investigators, this is the first objective analysis of the use of ultrasound devices during emergency air transport. Results from this study were published in the October - December 2000 issue of the Air Medical Journal. The medical device used in this study was the SonoSite, 180 hand-carried ultrasound system.

The study, "Trauma Ultrasound Feasibility During Helicopter Transport" details actual and simulated evaluations of trauma patients using the SonoSite 180 device, manufactured by SonoSite, Inc., by two air transport programs serving Level 1 trauma centers: Life Flight Network in Portland, Ore., and the University of California Davis Medical Center's Life Flight. In Portland the study was led by Daniel D. Price, M.D., medical director of Life Flight Network, assistant professor of emergency medicine at Oregon Health Sciences University and emergency physician at Legacy Emanuel Hospital and Health Center; all facilities are part of the trauma system in Portland. The study at UC Davis was led by Sharon R. Wilson, M.D., assistant professor, Division of Emergency Medicine.

"Prior to the SonoSite 180 system, using ultrasound to perform trauma examinations in flight was close to impossible due to the size, weight and image quality of traditional ultrasound devices," said Price. "Our study shows that this hand-carried ultrasound system can enable a transport team to make an immediate assessment of a patient's condition during transport, which can provide valuable information to support treatment decisions in flight and upon arrival at a hospital. This can save time and possibly improve the patient's outcome."

Study Results In this multi-center study, 10 trained health care professionals performed 21 standard four-view Focused Abdominal Sonography for Trauma (FAST) examinations on 14 patients (five actual, nine simulated) using the SonoSite 180 system. The FAST exam is a rapid basic assessment of the patient's abdomen and heart, and is used to identify evidence of injury, i.e., whether there is fluid (e.g., blood) present in the abdomen or around the heart. Being able to assess the extent of an injury can help determine whether the patient requires immediate surgery.

Following each transport, the examiners evaluated the ease of using the device to examine trauma patients in the environment of an airborne, often turbulent and noisy helicopter. Overall they found that the device easily overcame the difficulties posed by helicopter vibration and the challenges of scanning a patient amongst bedding, safety straps, intravenous (IV) catheters, monitor cables and ventilators. Only patient position in a cramped helicopter was rated as somewhat difficult. The mean examination duration was three minutes.

Implications for Emergency Medicine Professionals In an emergency situation where there can be many more injured patients than there are available health care facilities and professionals to treat them, having as much information as early as possible can help save the maximum number of lives by helping to ensure that the most critical patients are cared for first -- this is the concept of triage. According to the study investigators, being able to understand the scope of a patient's injury during, or even before, flight in order to provide information for making triage decisions has been challenging for helicopter transport units.

As space is limited in a helicopter, a new device used during transport must be practical, effective and space-efficient. Other standard diagnostic tests for acute trauma, such as computed tomography (CT) and diagnostic peritoneal lavage (DPL), are impractical for use outside a medical institution. Ultrasound, a painless and noninvasive exam, has been used in trauma center emergency departments, however the size and cost of traditional systems has precluded their use -- machines often weigh hundreds of pounds and are impossible to transport during helicopter transport.

This study demonstrates that the size, high quality imaging and all-digital composition of the SonoSite 180 system makes it the first device that is feasible for use by most transport programs. Using this portable system, helicopter transport teams have a tool that can help them diagnose and treat patients faster, or refer patients for more testing once they reach a hospital's emergency room.

Life Flight Network is a not-for-profit medical transport service provided by a consortium of Legacy Health System, Oregon Health Sciences University and the Sisters of Providence Health System. All are dedicated to improving patient outcomes by providing helicopter, fixed-wing airplane and specialty ground ambulance support to seriously ill or injured patients in a safe and timely manner. Life Flight Network is one of the oldest and most successful air ambulance systems in the country.

SonoSite, Inc. (Nasdaq: SONO) (www.sonosite.com) headquartered in Bothell, Wash., develops, manufactures, markets and sells a new class of hand-held, all-digital ultrasound systems designed to have the image quality of larger, more expensive systems, but small enough to be hand-carried from bedside to bedside and room to room in many clinical settings. SonoSite became an independent public company on April 6, 1998, as a result of a spin off from ATL Ultrasound.

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