Diagnostic Accuracy and Time-Saving Effects of Point-of-Care Ultrasonography in Patients With Small Bowel Obstruction: A Prospective Study

Abstract

Study objective: We evaluate the accuracy of point-of-care ultrasonography compared with computed tomographic (CT) scan and assess the potential time-saving effect of point-of-care ultrasonography in diagnosing small bowel obstruction.

Methods: This was a prospective observational study of a convenience sample of patients with suspected small bowel obstruction in an academic emergency department (ED). Physician sonographers were blinded to clinical data, laboratory results, and CT scan findings. Point-of-care ultrasonographic findings of small bowel obstruction was the primary outcome, defined as bowel-loop diameter greater than or equal to 25 mm with abnormal peristalsis. Maximum bowel dilatation, visible peristalsis, interluminal free fluid, and bowel wall thickness were evaluated. Time to completion of imaging results was abstracted from the medical records for each imaging modality.

Results: The study included 125 patients (median age 54.0 years [interquartile range 43 to 63 years]; 46% men), of whom 32 (25.6%) had small bowel obstruction, and 9 (7.2%) underwent surgery for it. Overall, the sensitivity of point-of-care ultrasonography for small bowel obstruction was 87.5% (95% confidence interval 71.0% to 96.5%), and specificity was 75.3% (95% confidence interval 65.2% to 83.6%). The area under the receiver operating characteristic curve to accurately predict small bowel obstruction was 0.74 (95% confidence interval 0.66 to 0.82). Results were similar across evaluated subgroups, including physician training level. The average time to obtain a CT scan report was 3 hours, 42 minutes; obtaining an abdominal radiograph took 1 hour, 38 minutes; and the mean elapsed time to complete point-of-care ultrasonography was 11 minutes.

Conclusion: In ED patients with suspected small bowel obstruction, point-of-care ultrasonography has a reasonably high accuracy in diagnosing small bowel obstruction compared with CT scan, and may substantially decrease the time to diagnosis.