Association of Electrolyte Changes and Inflammatory Markers with Renal Involvement in Children with Febrile UTI

Background: We need some simpler, cheaper, and less burdensome tools to investigate the severity of renal parenchymal involvement in children with clinical pyelonephritis. Objectives: The present study was designed to investigate the relationship between electrolyte changes with renal involvement as documented by dimercaptosuccinic acid (DMSA) scan in children with febrile urinary tract infection (UTI). Methods: This is a retrospective cohort study, involving 158 children aged two months to 14 years with febrile UTI admitted to Taleghani Hospital in Gorgan from 2018 to 2019. Their documents in hospital were analyzed. They were divided into two groups with positive or negative defects on DMSA scan. Clinical and laboratory data were studied. Statistical analysis was performed using SPSS version 18. Data were analyzed using independent t-test with normal distribution of variables, otherwise chi-square test was used. The statistical significance level of the study was considered 0.05. Results: Among the 158 children, 78 patients (49.4%) had normal DMSA scan results, and 80 patients (50.6%) had an abnormal result. The mean age in month was not different between the two groups. In patients with positive renal cortical defects on DMSA Scintigraphy (group 2), ESR was significantly higher than the first group (P < 0.05). The mean serum Na level in the second group was lower than in the first group; however, it was only slightly significant (P = 0.058). The two groups showed no difference with respect to serum potassium, urine specific gravity (SG), WBC count, and the duration of fever (P > 0.05). The frequency distribution of proteinuria was not different between the two groups (P = 0.836). Conclusions: We suggest that increased ESR, positive CRP, and the presence of reflux can predict renal parenchymal involvement in children with febrile UTI as evidenced by a positive finding on DMSA scan, and the presence of hyponatremia has a little predictive value in this regard.