Current Role of Emergency US in Patients with Major Trauma

Abstract

In patients with major trauma, focused abdominal ultrasonography (US) often is the initial imaging examination. US is readily available, requires minimal preparation time, and may be performed with mobile equipment that allows greater flexibility in patient positioning than is possible with other modalities. It also is effective in depicting abnormally large intraperitoneal collections of free fluid, which are indirect evidence of a solid organ injury that requires immediate surgery. However, because US has poor sensitivity for the detection of most solid organ injuries, an initial survey with US often is followed by a more thorough examination with multidetector computed tomography (CT). The initial US examination is generally performed with a FAST (focused assessment with sonography in trauma) protocol. Speed is important because if intraabdominal bleeding is present, the probability of death increases by about 1% for every 3 minutes that elapses before intervention. Typical sites of fluid accumulation in the presence of a solid organ injury are the Morison pouch (liver laceration), the pouch of Douglas (intraperitoneal rupture of the urinary bladder), and the splenorenal fossa (splenic and renal injuries). FAST may be used also to exclude injuries to the heart and pericardium but not those to the bowel, mesentery, and urinary bladder, a purpose for which multidetector CT is better suited. If there is time after the initial FAST survey, the US examination may be extended to extra-abdominal regions to rule out pneumothorax or to guide endotracheal intubation, vascular puncture, or other interventional procedures.

Bedside US imaging in multiple trauma patients. Part 1: US findings and techniques

“…In the literature, sensitivity of FAST in detecting free intraperitoneal fluid is 68-98 %. This great discrepancy of results probably occurred because the procedure was performed by US operators with different levels of experience and because the results were compared to different diagnostic standards, such as computed tomography (CT), laparotomy or clinical observation; however, a common finding is that the specificity of FAST is very high, about 86-100 % [50]. Visibility of free fluid at FAST mainly depends on the quantity of liquid and the distribution in relation to the particular anatomy of each patient, the presence of scars and/or adhesions and-last but not the least-on the conditions under which the examination is carried out and on the US operator's experience.…”

“…Sensitivity of FAST in the diagnosis of organ lesions is 44-95 % but specificity is high (84-100 %). The discrepancy of results is linked to different study designs and the examined organ [50]. In blunt trauma, the injuries affect the abdominal organs in the following order of frequency: spleen, liver, small intestine and retroperitoneal space (kidneys, hematomas).…”

Abdominal ultrasonography for patients with abdominal pain as a first-line diagnostic imaging modality

“…2B). Fluid in the abdominal cavity and high echo in the spleen suggested bleeding and damaging lesions, respectively (19). A total of 30 patients were admitted outside of regular working h and were subjected to abdominal US.…”

Laparoscopy Versus Laparotomy in Evaluation of Penetrating Abdominal Injuries.

“…However FAST had a limited role in the diagnosis of penetrating abdominal injuries as stated by Korner et al [7], in his study about 26-34 % of patients with penetrating abdominal injuries had organ lesions with no intraperitoneal free fluid and about 25 % of these patients required laparotomy.…”