Approximately one third of stable patients with significant intra-abdominal injury do not have significant intraperitoneal blood evident on admission. We hypothesized that a delayed, repeat ultrasound study (Secondary Ultrasound – SUS) will reveal additional intra-abdominal injuries and hemoperitoneum.
We performed a prospective observational study of trauma patients at our Level I trauma center from April 2003 to December 2003. Patients underwent an initial ultrasound (US), followed by a SUS examination within 24 hours of admission. Patients not eligible for a SUS because of early discharge, operative intervention or death were excluded. All US and SUS exams were performed and evaluated by surgical/emergency medicine house staff or surgical attendings.
Five hundred forty-seven patients had both an initial US and a SUS examination. The sensitivity of the initial US in this patient population was 31.1% and increased to 72.1% on SUS (p < 0.001) for intra-abdominal injury or intra-abdominal fluid. The specificity for the initial US was 99.8% and 99.8% for SUS. The negative predictive value was 92.0% for the initial US and increased to 96.6% for SUS (p = 0.002). The accuracy of the initial ultrasound was 92.1% and increased to 96.7% on the SUS (p < 0.002). No patient with a negative SUS after 4 hours developed clinically significant hemoperitoneum.
A secondary ultrasound of the abdomen significantly increases the sensitivity of ultrasound to detect intra-abdominal injury.
From the United States Army Institute of Surgical Research (L.H.B.), San Antonio, Texas; the University of Tel Aviv (D.S.), Tel Aviv, Israel; the University of Vermont (B.C.), Burlington, Vermont; and the University of Texas at San Antonio (S.M.C.), San Antonio, Texas.
Address for reprints: Mark McKenney, MD, DeWitt Daughtry Family Department of Surgery, Division of Trauma, Surgical Critical Care, P.O. Box 016960 (D-40), Miami, FL 33031; email: MMcKenne@miami.edu.