Emergency Department Diagnosis of Aortic Dissection by Bedside Transabdominal Ultrasound

A 47-year-old female presented to the emergency department (ED) complaining of epigastric abdominal pain for 1 week. The pain had been sharp, constant, and radiating to her back. She had also been feeling nauseous and had a few episodes of nonbilious, nonbloody vomiting. Review of systems was otherwise negative. The patient had a history of hypertension and multiple episodes of pancreatitis, the last about 6 months prior to this visit. Her social history was significant for frequent alcohol and cocaine use.

The patient was hemodynamically stable. On physical exam she appeared to be in significant pain. The abdomen had normal bowel sounds and was soft and nondistended, with tenderness to palpation in the epigastrium, no rebound or guarding, and no masses palpated. The rest of the physical exam was unremarkable.

The most likely diagnosis from the differential, given the history and physical above, was an exacerbation of her chronic pancreatitis. The patient continued to complain of pain and was given multiple doses of narcotic analgesics during the initial ED workup.

The electrocardiogram was nondiagnostic and the chest radiograph had no significant findings. Laboratory tests returned showing a lipase of 165 U/L and amylase of 174 U/L. Liver function tests and metabolic panel were all within normal limits. The complete blood count was significant for anemia with hemoglobin of 8.1 g/dL and hematocrit of 24%.

Given that the patient had a history of multiple episodes of pancreatitis, that she was continuing to require multiple large doses of narcotics, and that her lipase was only mildly elevated, a decision was made to order a computed tomography (CT) scan of her abdomen/pelvis. While awaiting this test, the ED physicians had the opportunity to perform a bedside abdominal ultrasound, with the intention of imaging her pancreas for a pseudocyst or surrounding fluid.

The ultrasound revealed an unsuspected finding. While the pancreas appeared relatively unremarkable, there appeared to be a flap in the aorta, consistent with an aortic dissection (Figure 1 and Video Clip S1, available as supporting information in the online version of this paper). The patient was promptly taken to CT for a dissection protocol scan. This showed a dilated abdominal aorta (measuring up to 4.3 cm) with a flap seen within, just inferior to the gastroesophageal junction, consistent with an aortic dissection (Figure 2). This was followed by a magnetic resonance angiography of the chest and proximal abdominal aorta, which showed a type B aortic dissection beginning just distal to the left subclavian artery, approximately 7.6 cm in length, with thrombosis of the proximal false lumen and recanalization.

Figure 1.  Transabdominal ultrasound showing a flap in the aorta, consistent with an aortic dissection.

Figure 2.  CT image showing a dilated abdominal aorta with an aortic dissection.

The dissection was determined to be chronic and stable. Vascular surgery recommended blood pressure control using various antihypertensives, including clonidine, hydralazine, and isosorbide. The patient remained stable and was discharged from the hospital 9 days later.