Blunt Abdominal Trauma and the FAST Exam

October 2005

Blunt Abdominal Trauma and the FAST Exam

You are a recent Barnes Hospital EM graduate working your first overnight shift at a local level II ED. The night has gone smoothly until the paramedics bring in a 25 year-old female who is boarded and collared after being involved in a MVC. She was an unrestrained driver who lost control of her car on a wet road and collided with a telephone pole at 35 mph with significant damage to the front end of her vehicle.

She is awake and complains of isolated upper abdominal pain where she hit the steering column. Her initial vital signs (VS) are BP 85/58, P 115, R 22, T 37.4, pulse ox 99%. She is resuscitated with supplemental oxygen, 2 large-bore IV’s, and a liter of normal saline. Labs are pending and packed red blood cells are available at the bedside. Clinically, the patient responds well to the fluid with repeat VS BP 105/65, P 90, R 20, and pulse ox 100%.

Your ED happens to have an ultrasound (US) machine. Since you have been trained in emergency sonography by the masters, you quickly fire it up. A 4-view FAST scan of the patient demonstrates 2 findings. First, there appears to be an obvious 1.5 centimeter anechoic fluid stripe at Morison’s pouch. Secondly, the patient has a viable 9-10 week IUP.

You realize that surgery will need to be involved immediately and contact the attending trauma surgeon on call. After giving him the story, the surgeon tells you to get an abdominal-pelvic trauma CT while he drives to the hospital.

Meanwhile, the patient is informed of her dual sonographic findings. She has several questions and expresses some concerns. First, she wants to know how certain you are of the abnormal RUQ US findings. Have you done a lot of these FAST scans before? What about in pregnant patients? She states that she definitely does not want the CT for fear of excessive radiation to the baby during the formative weeks of the first trimester. She also wants to know why the surgeon has been called and “if they‘re going to cut me anyway”, what is the benefit of the CT?

Nice little quagmire, huh? Although the teaching is that single warranted trauma CT is generally safe in pregnancy, the patient is convinced otherwise and is refusing the study. Her conviction makes you question yourself. Although you’ve done numerous FAST scans and 1st trimester ultrasounds, you never had them in the same patient. How sensitive is the FAST exam in pregnant patients? Finally, is there anyway to predict either on US findings alone or in combination with physical exam data which patients would benefit more from further imaging or from going directly to laparotomy?

PICO Question

Population: Adults with blunt abdominal trauma and abdominal pain

Intervention: Screening ED Ultrasound FAST exam

Comparison: No FAST exam

Outcome: Subsequent cause-specific laparotomy and/or mortality

Your initial search strategy is to query OVID (1996-present) using a combination of search terms:

  • Ultrasound with MESH headings “ultrasonography” and “ keyword” (91, 625 hits).
  • Blunt abdominal trauma with MESH headings “wounds, non-penetrating”, “abdominal injuries”, “multiple trauma”, and “blunt abdominal keyword” (12, 447 hits)
  • You combine the findings from search strategy #1 and #2 (738 hits).
  • You filter the findings from # 3 through Annals of EM (5 hits including the PGY III article), American Journal of EM (9 hits including the PGY II article), and Journal of EM (10 hits including the PGY IV article).

Dissatisfied with your results, you ask Dr. Theodoro for a list of articles relevant to blunt abdominal trauma and screening ED US which provides one dated article from Dr. Ma on the US evaluation of pregnant trauma patients. You utilize a Web of Science cited reference search from Ma’s article to obtain the PGY I article.


First years: Blunt Abdominal Injury in the Pregnant Patient: Detection with US. Radiology 2004; 233: 463-470.

Second years: Operative versus No-Operative Management of Blunt Abdominal Trauma: Role of Ultrasound-measured Intraperitoneal Fluid Levels. Am J Emerg Med 2001; 19: 284-286

Third years: Use Of Ultrasound to Determine Need for Laparotomy in Trauma Patients. Ann of Emerg Med 1997; 29: 323-330

Fourth years: The FAST is positive, now what? Derivation of a clinical decision rule to determine the need for therapeutic laparotomy in adults with blunt torso trauma and a positive trauma ultrasound. J of Emerg Med 2005; 1: 15-21


First, Second, Third Year Residents: use the Diagnosis Critical Appraisal Form

Fourth Year Residents: use the Clinical Decision Rule Critical Appraisal Form


Article 1: 1st, 2nd, & 3rd use the Diagnosis Critical Appraisal Form 4th use the Clinical Decision Rule Critical Appraisal Form

Article 2: Operative versus Non-operative Management of Blunt Abdominal Trauma: Role of Ultrasound-measured Intraperitoneal Fluid Levels; AJEM 2001;19:4

Article 3: Use of Ultrasound to Determine Need for Laparotomy in Trauma Patients, Annals EM1997, 29: 323-330

Article 4: The FAST is Positive, Now What? Derivation of a Clinical Decision Rule to Determine the Need for Therapeutic Laparotomy in Adults with Blunt Trauma and a Positive Trauma Ultrasound, Journal of EM 2004; 29:15-21