This patient arrives in the Emergency Department after an assault with penetrating abdominal trauma and is hemodynamically stable on exam. The first step in evaluating any trauma patient involves the primary survey. The primary survey is also known as the “ABCDEFs” of trauma. This stands for Airway, Breathing, Circulation, Disability, Exposure, and FAST exam (Focused Assessment with Sonography in Trauma). Each letter should be assessed in alphabetical order to avoid missing a time sensitive life-threatening condition. The primary survey should be conducted prior to taking a full history. After the primary survey, a more detailed physical exam (secondary survey) is conducted, followed by interventions and a focused patient history.
The FAST exam is a quick sonographic exam that requires the practitioner to look at 4 anatomical areas for signs of internal injuries. The 4 areas are the right upper abdominal quadrant, left upper abdominal quadrant, pelvis, and subxiphoid (cardiac) areas. The addition of views for each lung (1 view for each lung) is known as an E-FAST, or extended FAST exam. The presence of an anechoic (black) stripe on ultrasound indicates the presence of free fluid. In the setting of trauma, free fluid is assumed to be blood. The presence of free fluid on a FAST exam is considered a “positive FAST exam”. This patient has no free fluid between the right kidney and liver. There also is no free fluid above the diaphragm to indicate a hemothorax. The question stem notes that all other FAST exam views are nonremarkable. Therefore, this patient has a negative FAST exam. See labelling of the FAST exam image below.
An exploratory laparotomy (Choice A) would be indicated in a patient with penetrating or blunt trauma, a positive FAST exam, and hemodynamic instability. This patient has a negative FAST exam and is hemodynamically stable. Packed red blood cell infusion (Choice B) would be indicated in the setting of hemodynamic instability and trauma, as this is assumed to be hemorrhagic shock. This patient is not tachycardic or hypotensive. A urinalysis to check for hematuria (Choice D) may be a helpful adjunctive investigation to evaluate for renal or bladder injury, but it is not the most crucial next step in management. Performing a CT scan of the abdomen and pelvis (Choice C) is the best next step as the patient is hemodynamically stable with a negative FAST exam and a penetrating abdominal injury. The CT scan will help further evaluate for any internal injuries that may require operative repair. See the algorithm below for further detail on an abdominal trauma work flow. Correct Answer: C
Joey Ciano, DO, MPH is an Emergency Medicine Physician from New York, USA. He completed his Emergency Medicine Residency in Brooklyn, NY and a Fellowship in Global Emergency Medicine in the Northwell-LIJ Health System. He is interested in building the educational infrastructure of EM in countries where EM is not yet recognized as a field and in countries that are in the early stages of this process. He has partnered with international NGOs in EM educational projects and works as a visiting EM faculty member in West Bengal, India. He is excited to collaborate with the other authors of the iEM Education Project to contribute to world of FOAM-ed.
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