Findings of Non-enhanced Abdominal Computed Tomography for Pain Management of Acute Renal Colic Patients in the Emergency Department

Study Objectives: To identify non-enhanced computed tomography (NECT) findings related to repeated requirement of painkiller, hospitalization and revisits within 5 days of discharge among acute renal colic patients. Patients and methods: A retrospective observational study was performed for all patients (age > 18 years) with acute renal colic who visited the emergency department (ED) between 2012 and 2015. NECT findings of acute ureterolithiasis (size, location, hydronephroureter, perinephric infiltrations and soft-tissue rim sign) were analysed for their relationships to repeated administration of painkiller, hospitalization and ED revisit. Results: Of total 862 patients enrolled, 305 (35.4%) required repeated administration of pain medication. In the NECT findings, hydronephroureter was more prevalent in the repeated administration of painkiller group (61.3% vs. 53.7%), but did not show independent relationship. Sixty-eight (7.9%) were hospitalized and 44 (5.1%) returned to the ED. The significant findings associated with hospitalization were hydronephroureter (OR [Odd Ratio] 1.92, 95% CI [Confidence Intervals] 1.04-3.54) and mid (5-7 mm) / large-size ( > 7mm) ureteral stones (OR 2.66, 95% CI 1.49-4.76 and OR 4.78, 95% CI 1.80-12.70). The soft-tissue rim signs (OR 2.16, 95%CI 1.07-4.37) and proximal/mid location of stones (OR 3.21, 95% CI 1.26-8.20 and OR 2.53, 95% CI 1.19-5.37) were independently associated with ED revisit. Conclusions: Among the NECT findings of acute ureterolithiasis, hydronephroureter and stones > 5 mm in size were independently associated with the need of hospitalization. The soft-tissue rim sign and proximal/mid location of stones were independently associated with ED revisit within 5 days.