Free fluid in Morison's pouch on bedside ultrasound predicts need for operative intervention in suspected ectopic pregnancy.

BACKGROUND Ectopic pregnancies are frequently present in women who present to the emergency department with pregnancy and abdominal pain or bleeding, a subset of whom may require operative intervention. OBJECTIVES To prospectively determine if emergency physician (EP)-performed transabdominal pelvic ultrasonography (US) with determination of free abdominal fluid in the hepatorenal space predicted the need for operative intervention. METHODS Patients who were suspected to have an ectopic pregnancy were prospectively enrolled over a ten-month period. An EP-performed bedside transabdominal pelvic US that included a view of the hepatorenal space (Morison's pouch) for free fluid. The EP US was classified as intrauterine pregnancy (IUP) or no definitive IUP, with Morison's pouch classified as positive or negative. The majority of patients had a subsequent transvaginal pelvic US performed by the Department of Radiology. Patients were followed up for radiology results, need for operative intervention, and ultimate outcome of the pregnancy. RESULTS There were 242 patients enrolled, with an average time to complete the EP US of 4 minutes and 27 seconds. There were 28 ectopic pregnancies diagnosed (11.6%), of which 18 patients underwent operative intervention. Free fluid in Morison's pouch was identified in ten patients, nine of whom underwent operative intervention, yielding a positive likelihood ratio of 112 (95% confidence interval = 15 to 831) for patients with suspected ectopic pregnancy who required operative intervention. CONCLUSIONS Free intraperitoneal fluid found in Morison's pouch in patients with suspected ectopic pregnancy may be rapidly identified at the bedside by EP-performed US and predicts the need for operative intervention.