Image 1: Hepatorenal space with a large amount of anechoic fluid in Morison’s pouch and around the caudal edge of the liver.
by Dr. A. Aiken, Bronx, NYC USA
A 20s F with no medical history presents with acute abdominal pain radiating to her right shoulder. She’s on oral contraceptive pills, has no vaginal bleeding or urinary symptoms. Initial vitals: BP 115/80 mmHg, HR 99 bpm, Temp 99.1 F, RR 26, SpO2 99%. She has diffuse abdominal tenderness, and is unable to stay still, writhing in pain. She becomes diaphoretic. Repeat vitals: BP 70/50, HR 120, Temp 99.1, RR 26, SpO2 99%.
POCUS hepatorenal space is concerning for a large amount of anechoic fluid in Morrison’s pouch and around the caudal edge of the liver (Image 1 above). Gynecology is called immediately to the bedside, blood bank has 2 units of O- blood on the way, and IV fluids are running. Urine pregnancy results positive via catheterization, and she’s taken to the operating room. Two liters of hemoperitoneum is evacuated from her abdomen and a ruptured ectopic pregnancy is identified in the left fallopian tube where hemorrhage is identified and controlled. She’s transfused blood products with improvement in hemodynamics, and is discharged the following day.
POCUS Pearls: Ectopic pregnancies are the leading cause of maternal mortality in the first trimester. To risk stratify a female patient with acute, undifferentiated abdominal pain look to identify free fluid in the hepatorenal space, specifically the caudal edge of the liver. Free fluid does not definitively rule in a ruptured ectopic pregnancy, but in the context of a positive pregnancy test and no intrauterine pregnancy, it is the diagnosis of greatest concern. Free intraperitoneal fluid found in Morison’s pouch in patients with suspected ectopic pregnancy predicts the need for operative management and is associated with a reduced time to diagnosis and treatment.