Transient renal impairment in the absence of pre-existing chronic kidney disease in patients with unilateral ureteric stone impaction.

This study aims to describe the rate and characteristics of transient renal impairment in unilateral ureteric stone patients without chronic kidney disease (CKD) and to identify factors that may have influenced renal function of these patients. Unilateral ureteric stone patients who visited our hospital's emergency department from December, 2009 to December, 2015 were divided into two groups based on estimated glomerular filtration rate (eGFR): group I (patients with eGFR ≥ 60 ml/min/1.73 m2) and group II (eGFR < 60 ml/min/1.73 m2). A univariate comparison between groups I and II was performed. Multivariable logistic regression analysis was performed to determine factors that influenced renal function. There were 107 patients in group II, which constituted 5.6 % of the total patients. In the multivariable logistic regression analysis, age (p < 0.001, odds ratio [OR] = 1.069, confidence interval [CI] = 1.049-1.089), hypertension (p < 0.001, OR = 2.302, CI = 1.467-3.611), stone size (p = 0.001, OR = 1.141, CI = 1.057-1.231), white blood cell count (p = 0.001, OR = 1.132, CI = 1.055-1.215) and hematuria (p < 0.001, OR = 0.383, CI = 0.231-0.636) were found to be independent factors for renal impairment. Based on the results of this study, the rate of renal impairment was 6 % of the unilateral ureteric stone patients without pre-existing CKD. Age and hypertension were found to be independent factors for renal impairment; NSAIDs should be used cautiously or other agents for pain relief such as opioids should be considered in old aged patients with hypertension.