Factors determining renal impairment in unilateral ureteral colic secondary to calcular disease: a prospective study.

OBJECTIVE: To evaluate all possible risk factors that can cause impairment of overall renal function in patients with unilateral ureteral calculus and a normal contralateral kidney. METHODS: This is a prospective study of 90 patients who presented to our institute complaining of renal colic secondary to unilateral ureteral calculus. All patients were evaluated with a thorough history, physical examination, and laboratory and radiological investigations including renal function testing, urine analysis, non-contrast computed topography, and radionucleotide scan. Patients were divided into two groups according to their calculated creatinine clearance using the Modification of Diet in Renal Disease (MDRD) formula. Group I (favorable group) had a creatinine clearance >60 ml/min, while group II (unfavorable group) had a creatinine clearance <60 ml/min. RESULTS: The patients' mean age ± SD was 38.8 ± 11.4 years. Group I included 54 patients (60 %), while group II included 36 patients (40 %). On univariate analysis, factors that were associated with overall renal function impairment were patients' age, urea-to-creatinine ratio (UCR), use of nonsteroidal anti-inflammatory drugs, stone location, and presence of obstruction. However, using binary logistic regression analysis, only patients' age, UCR, and presence of obstruction sustained statistical significance in association with renal function impairment. CONCLUSION: The study of factors that help explain the presence of renal impairment in patients with unilateral ureteral calculus is important in the clinical setting. Patients' age, urea-to-creatinine ratio, and degree of obstruction seem to be significantly associated with overall renal function impairment.