Contribution of point of care ultrasound for ruling out small bowel obstruction in emergency departments: study protocol of the diagnostic, observational, prospective and multicentre OCCLUS-POCUS study

Introduction Abdominal pain is a common presentation in emergency departments. Among these cases, small bowel obstruction (SBO) is a common diagnosis.

Diagnostic procedure is currently based on CT, an imaging modality associated with radiation exposure. Studies suggest good accuracy of point of care ultrasound (POCUS) for SBO.

Through the OCCLUS-POCUS study, we aim to evaluate the POCUS ability to rule out SBO in patients with low to moderate clinical suspicion, thereby avoiding unnecessary CT scans. Methods and analysis This prospective, observational and multicentre study will involve 15 French emergency departments.

Eligible patients will be adults presenting with low or moderate suspicion of SBO (based on Gestalt clinical probability). Exclusion criteria will include prior imaging confirmed SBO, pregnancy or breastfeeding.

POCUS will be performed by emergency physicians prior to CT scans, which serve as the diagnostic gold standard. The primary endpoint will be the negative predictive value (NPV) of POCUS for SBO.

Secondary endpoints will include POCUS diagnostic accuracy, time intervals between POCUS and CT and factors associated with false-positive or false-negative results.