Quantitative Sensitivity of Ultrasound in Detecting Free Intraperitoneal Fluid

TLDR

The minimum detectable volume of intraperitoneal fluid in Morison's pouch by ultrasound in trauma is unclear. The study aimed to determine ultrasound sensitivity for detecting intraperitoneal fluid using a diagnostic peritoneal lavage model in a blinded prospective design. One hundred patients were studied by blinded attending physicians and residents from emergency medicine, radiology, and surgery who continuously scanned Morison's pouch during DPL fluid infusion. The mean detectable volume was 619 mL, with only 10 % detecting less than 400 mL, and overall sensitivity at 1 L was 97 %, indicating that reliable detection requires larger volumes than previously reported.

Abstract

The minimum volume of intraperitoneal fluid that is detectable in Morison's pouch with ultrasound in the trauma setting is not well defined. To evaluate this question, we used diagnostic peritoneal lavage (DPL) as a model for intraperitoneal hemorrhage and undertook a blinded prospective study of the sensitivity of ultrasound in detecting intraperitoneal fluid. Participants included attending physicians and residents in emergency medicine, radiology, and surgery. During the infusion of the DPL fluid, participants continuously scanned Morison's pouch until they detected fluid. All participants were blinded to the rate of infusion and the volume infused. One hundred patients were entered into the study. The mean volume of fluid detected was 619 mL. Only 10% of participants detected fluid volumes less than 400 mL and the overall sensitivity at one liter was 97%. We conclude that reliable detection of intraperitoneal fluid in Morison's pouch requires a greater volume than has been previously described.