Safe discharge and outpatient investigation of ureteric colic: a retrospective analysis

Computed tomography of the kidneys, ureters and bladder is the recommended imaging modality for suspected urolithiasis. Early scanning is advised in guidelines, but there is limited published evidence to support this recommendation.

In a retrospective study, we reviewed patients managed according to a local guideline. Patients without high-risk features were either imaged during their initial visit (if in the daytime) or discharged for outpatient scans. Complications, unplanned returns, final diagnosis, and intervention rates were compared between groups.

Fifty-four patients were scanned during their initial visit and 151 were scanned as an outpatient at a median interval of 10 days. Unplanned return rates were lower in those scanned as outpatients (7.3 vs. 24.1%), with no significant difference in complications (2.0 vs. 3.7%; none leading to permanent harm). Those scanned as outpatients were less likely to have a stone proven by imaging (39.7 vs. 64.8%), but did not have a significantly higher rate of proven alternative diagnosis (9.3 vs. 13.0%).

There is no evidence in this cohort that discharging patients for outpatient imaging is associated with poorer outcomes, provided that an appropriate clinical risk assessment is carried out.