The Risk Factors of Recurrent Febrile Urinary Tract Infection within 1 Year in Urinary Stone Patients with Acute Obstructive Pyelonephritis

Abstract

Purpose: To identify and evaluate the risk factors for the development of recurrent febrile urinary tract infection (fUTI) among patients with previous urinary stone and acute obstructive pyelonephritis (OPN). Materials and Methods: We retrospectively reviewed the medical records of 52 patients, who had urinary tract stones presented with OPN, between 2010 and 2015. Following their initial treatment, patients who were subsequently admitted with fUTI were included.Results: The mean age of patients was 62.2±14.6 years, and the mean follow-up duration was 26.0±20.39 months. Escherichia coli was found to be the dominating organism (68.2%, 15/22) in the initial urine culture. Patients were divided into two groups: The recurrent fUTI group (n=23) and the non-recurrent fUTI group (n=29). Between these two groups, significant differences were found with respect to diabetes history (recurrent group: 47.8% vs. non-recurrent group; 17.2%, p=0.018), stone location (kidney, 60.9% vs. ureter, 31.0%, p=0.031), and initially positive urine culture (60.9% vs. 27.6%, p=0.016). In a multivariate analysis, having an initially positive urine culture (95% confidence interval, 1.130-224.117; p=0.040) was identified as being an independent risk factor for developing recurrent fUTI. In a multivariate analysis, the initial laboratory test finding of acute renal insufficiency (ARI, p=0.019) and presence of a kidney stone (p=0.022) were significant factors associated with a newly-diagnosed-positive urine culture diagnosis. Conclusions: Having an initially positive urine culture was a significant risk factor for the development of recurrent fUTI in urinary stone patients with acute OPN. In addition, repeated urine tests were also needed in patients with ARI or renal stones during the follow-up period.