In severe cases, and in those with a delayed diagnosis, small bowel obstruction may lead to strangulation, necrosis, intestinal perforation, and peritonitis. Consequently, a more accurate diagnostic plan that enables expedited management, is critical.
Compared with computed tomographic (CT) scan, point-of-care ultrasonography has demonstrated high accuracy in diagnosing small bowel obstruction in the emergency department, according to a study recently published in Annals of Emergency Medicine. This may result in a significantly shorter time to diagnosis.
This prospective, observational study included 125 individuals suspected of having small bowel obstruction; 46% were men and the median age was 54 years (43-63). This study took place in an academic emergency department, where the ultrasound scans were performed by physicians who were blinded to the laboratory and CT results. The primary study end point was the accuracy of point-of-care ultrasonographic scans, with small bowel obstruction defined by bowel loop diameter of ≥25 mm and abnormal peristalsis. Participants were evaluated for detectable peristalsis, bowel dilation, bowel wall thickness, and interluminal free fluid. Medical records were examined to extract the time to completion of imaging results, with Kaplan-Meier time-to-event curves used to present the duration of time to available imaging results.
Among the study population, 25.6% (n=32) were diagnosed with small bowel obstruction, 46.9% (n=15) of whom had undergone abdominal surgery. Point-of-care ultrasonography was found to have a sensitivity of 87.5% (95% CI, 71.0-96.5) and a specificity of 75.3% (95% CI, 65.2-83.6). Ultrasonography demonstrated accuracy in predicting small-bowel obstruction regardless of physician training level (attending vs resident) and whether or not obstruction risk factors were present. Compared with the time to obtain a CT scan (3 hours 42 minutes) and a radiograph (1 hour 38 minutes), ultrasonography had a mean elapsed point-of-care time of 11 minutes. A significant association was identified between to-and-fro peristalsis and risk for small bowel obstruction, with an adjusted odds ratio of 7.11 (95% CI, 1.27-39.88).
Limitations to this study include a small sample size of patients from a single academic institution, the use of convenience sampling, the lack of an “indeterminate” entry option for physicians, a lack of comparison between the study’s 2 ultrasonographic machines, a single point-of-care ultrasonographic examination on the participants, and potential selection bias.
The study researchers conclude that point-of-care ultrasonography is a demonstrated and reliable diagnostic tool for accuracy in diagnosing small bowel obstruction and abnormal peristalsis, compared with the standard method of CT scans. Additionally, this method is less expensive and can provide a faster and noninvasive option for both clinicians and patients to confirm or reject suspicion of small bowel obstruction.
Boniface KS, King JB, LeSaux MA, Haciski SC, Shokoohi H. Diagnostic accuracy and time-saving effects of point-of-care ultrasonography in patients with small bowel obstruction: a prospective study [published online July 23, 2019]. Ann Emerg Med. doi: 10.1016/j.annemergmed.2019.05.031