BEFAST (Bubble-Enhanced FAST) for the Evaluation of Solid Organ Injury

Overview

The Focused Assessment with Sonography for Trauma (FAST) exam is widely used and accepted as part of advanced trauma life support (ATLS) protocol, but its low sensitivity for identifying solid organ injury in the absence of hemoperitoneum is a significant limitation. Contrast-enhanced ultrasound (CEUS) has the potential to significantly enhance the evaluation of the trauma patient with acute intra-abdominal injury through the use of intravascular microbubbles that allow direct visualization of lacerations to solid organs. European studies have demonstrated that ultrasound contrast markedly improves the sensitivity of ultrasound in detecting solid organ injury, when the exam is performed in the radiology suite. The researchers hypothesize that the bubble-enhanced FAST or BEFAST exam will be more sensitive than traditional FAST for identification of solid organ injury in hemodynamically stable blunt abdominal trauma patients when performed by emergency providers.

Blunt abdominal trauma, whether from motor vehicle crash, assault, fall, or recreational injury, is a leading cause of morbidity and mortality. According to the 2016 National Trauma Database, 12% of all patients with trauma admissions had abdominal trauma, the majority of which is blunt. The diagnosis of intra-abdominal injury due to blunt abdominal trauma can be challenging. The physical exam is unreliable in patients with altered mental status or with impairment due to drugs or alcohol. While computed tomography (CT) can rapidly and accurately diagnose injury, emergency physicians have raised concerns that the use of CT has become overly liberal. The risks of overutilization of CT in hemodynamically stable blunt abdominal trauma include increased health care costs, lengthy stays in the emergency department, risks of contrast-induced nephropathy and radiation-induced malignancy, and patient anxiety when "incidentalomas" are discovered that need extensive and often unnecessary workup. The Focused Assessment with Sonography for Trauma (FAST) exam is widely used and accepted as part of the advanced trauma life support (ATLS) protocol, but its low sensitivity for identifying solid organ injury in the absence of hemoperitoneum is a significant limitation. Contrast-enhanced ultrasound (CEUS) has the potential to significantly enhance the evaluation of the trauma patient with acute intra-abdominal injury through the use of intravascular microbubbles that allow direct visualization of lacerations to solid organs. In 2016, the Food and Drug Administration (FDA) approved Lumason (sulfur hexafluoride lipid-type A microsphere) for characterization of focal liver lesions with CEUS in both adult and pediatric patients, opening new areas of research in the United States. Lumason is a second generation contrast agent that is more stable than previous ultrasound contrast agents and does not require refrigeration. Although approved for intravascular and intravesical use, Lumason's use in a trauma exam is off-label in the United States. After participants provide informed consent, a baseline FAST exam will be performed and documented. This exam will be distinct from the initial ATLS resuscitation FAST in order to avoid any interference in the trauma evaluation. If not already placed, an intravenous line will be established according to standard practice for trauma patients. Following the FAST exam, a bubble-enhanced FAST (BEFAST) exam will be performed using Lumason as the contrast agent. As part of the standard of care, participants will have a CT exam performed within 24 hours, which will provide the gold standard for diagnosis of solid organ trauma.