Does computed tomographic scan affect diagnosis and management of patients with suspected renal colic?

Patients with renal colic commonly present to the emergency department (ED) and are usually treated with analgesics, antiemetics and hydration. Computed tomographic (CT) scan is commonly utilized in evaluating patients with suspected renal colic.

We compared diagnosis and treatment plans before and after CT in patients with suspected renal colic with the aim to evaluate how often changes in diagnosis, treatment and disposition are made.

In this prospective observational study, we enrolled a convenience sample of clinically Stable ED patients older than 17 with suspected renal colic for whom CT was planned. Exclusion criteria were: chronic kidney disease, urinary tract infection, recent CT and history of previous kidney stone. Pre-CT and Post-CT surveys were completed by the treating provider.

The discharge diagnosis was renal colic in 62 of 93 enrolled patients (67%). Urinalysis showed blood in 52 of these patients (84%). CT confirmed obstructing kidney or bladder stone in 50 patients. There were five cases of alternative diagnoses noted on CT scan. After CT scan, 7 patients had changes in disposition. Sixteen providers felt that CT would not change management. In these cases, CT offered no alternative diagnosis and didn't change disposition.

CT scan didn't change management when providers did not expect it would. This indicates that providers who are confident with the diagnosis of renal colic should consider forgoing a CT scan. CT scan did occasionally find important alternative diagnoses and should be utilized when providers are considering other concerning pathology.