144 An “Ultrasound-First” Protocol in Patients With Suspected Acute Diverticulitis Is Associated With Reduction in Time and CT Utilization

Abstract

Although CT scans are highly accurate in diagnosing diverticulitis, they are costly, prolong ED length of stay, and expose patients to ionizing radiation. The objective of this study was to investigate the potential time-saving effect and reduction in CT scan utilization when point-of-care ultrasound (POCUS) was employed as a first-line imaging modality in the diagnosis of acute diverticulitis. This was a prospective observational study in patients with suspected diverticulitis who underwent both POCUS and CT in their ED visits. To estimate the impact on CT scan utilization, negative CT scans and those with simple diverticulitis (Hinchey “0”) were considered avoidable. To determine the potential CT reduction associated with an ultrasound-first protocol in ED patients with uncomplicated diverticulitis, we applied the findings from our study to institutional medical records of ED visits for diverticulitis over a period of 3.5 years. To estimate the time-savings of an ultrasound-first protocol, we compared the arrival time to the time in which the CT read was available as compared to the completion of POCUS. 72 patients in our study had both POCUS and CT scans. In 35% (25/72), both POCUS and CT showed simple uncomplicated diverticulitis. In 35% (25/72) both POCUS and CT were negative. In 30% (22/72), the CT scan showed complicated diverticulitis, identified an alternative diagnosis or changed management. Overall, CT scans could have been avoided in 70% (50/72) of the cases. When this rate of 70% is applied to the number of patients who had a CT scan for diverticulitis in the ED over a period of 3.5 years, approximately 959 CT scans (70% of 1,370 CT scans), or 274 CT scans annually could have been avoided if POCUS was used as the first-line diagnostic tool. As for the time-saving impact, the average time from arrival to completion of CT and POCUS scans were 5.3 hours (95% CI 4.9-5.7) and 1.1 hours (95% CI 1.0-1.3), respectively. A mean difference of 4.2 hours (95% CI 3.9- 4.5) reflects the potential decrease in length of stay for patients in the ED. In ED patients with uncomplicated diverticulitis, using POCUS as a first-line imaging can substantially reduce the number of CT scans and time to diagnosis. There could be substantial implications and reduction on patient length of stay, radiation, and cost.