Introduction: Our objective was to determine whether unilateral calculus-induced ureteric obstruction on computed tomography (CT) was independently associated with the need for urological intervention and 30-day return to the emergency department (ED). Methods:We performed a retrospective cohort study of patients with symptomatic urinary calculi diagnosed by unenhanced helical CT. Stepwise regression analysis was used to determine the predictors of urological intervention and 30-day return to the ED. Potential predictors assessed included: patient demographics, calculus size, calculus location, degree of obstruction, analgesic doses, signs and symptoms of infection, serum creatinine, cumulative intravenous fluid administered, and the prescription of medical expulsive therapy. Results: Of 195 patients, 81 (41.5%) underwent urological intervention. The size of the calculus, its location, and the cumulative opioid dose were all independent predictors for urological intervention. Every 1 mm increase in calculus size increased the likelihood of intervention 2.2 times (odds ratio [OR] 2.17; 95% confidence interval [CI] 1.67-2.85). Proximal stones were 4.7 times more likely to require intervention than distal calculi (OR 0.21; 95% CI 0.09-0.49). Every 10 mg increase in morphine was associated with a 30% increase in the odds of intervention (OR 1.30; 95% CI 1.07-1.58). Degree of obstruction was not associated with the need for urological intervention. Finally, none of the variables were predictors for 30-day return to the ED. Conclusions: Although stone size, proximal location, and severe pain, as indicated by higher opioid doses, were associated with the need for intervention, the degree of obstruction did not influence the management of patients with CT-defined urinary calculi.

Introduction: Renal colic is a common presentation which exerts a significant burden on healthcare infrastructure. A significant proportion of patients managed with observation may return to the Emergency Department (ED) prior to spontaneous passage due to inadequate analgesia. It is unclear whether early urologist consultation would limit the burden of renal stones by reducing returns to the ED. We wished to determine whether urologist referral from the ED department is associated with fewer returns to the ED with renal colic. Methods: We conducted a retrospective chart review using RECORD methodology of consecutive patients diagnosed with CT-confirmed, ureteric or renal calculi in our ED over a two-year period. Disposition was categorized as either hospital admission, outpatient urologist referral, follow up with primary care, or no follow up. The primary outcome was the 30-day ED re-presentation for renal colic. Multivariate logistic regression was used to identify predictors for ED-return. Results: In total, 232 patients met our inclusion criteria. Urgent or outpatient urologist referral was not associated with a significantly lower ED return rate when compared to patients with no follow-up. Surprisingly, urologic intervention and stent placement were both independent predictors for ED return (OR: 2.03; 95% CI: (1.06-3.88); p:0.03) and (OR:2.08; 95% CI: (1.07-4.05). Conclusion: A significant proportion of patients who underwent urologist-led intervention returned to the ED with renal colic. Further study may help clarify the role of early urologist referral for renal calculi, as this may not reduce ED return rates when compared to conservative management.