Hematocrit Sign Elucidates Cause of Abdominal Pain

A 78-year-old male with chronic kidney disease on peritoneal dialysis developed unprovoked bilateral pulmonary embolisms. He was started on IV unfractionated heparin, but shortly thereafter developed severe pain and a small firm abdominal nodule near his dialysis catheter site. The diagnosis was unknown, and the initial plan was watchful waiting, until point-of-care ultrasound (POCUS) was used. POCUS revealed an ovoid mass with hyperdensity in the gravity dependent regions with spontaneous movement. This appearance was classic for the hematocrit sign. When combined with the clinical presentation, this was concerning for a rectus sheath hematoma. An urgent CT of the abdomen confirmed this several hours later. POCUS allowed for rapid bedside diagnosis, which expedited appropriate care in a potentially life-threatening situation.