Pyonephrosis among Patients with Pyelonephritis Admitted in Department of Nephrology and Urology of a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Introduction: Pyonephrosis is a severe complication of pyelonephritis leading to rapid progression to sepsis and loss of renal function resulting in nephrectomy. Early identification of pyonephrosis based on clinical or radiological characteristics amongst pyelonephritis is paramount. This study aimed to determine the prevalence of pyonephrosis among patients with pyelonephritis admitted to the Department of Nephrology and Urology of a tertiary care centre. Methods: This descriptive cross-sectional study was done in a tertiary care centre among patients with pyelonephritis from 1 July 2016 to 31 Jan 2021. Ethical approval was obtained from Institution Ethics Committee (Reference number: IEC/56/21). The available clinical, demographic and laboratory parameters were recorded from the hospital records in a predesigned proforma. A convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated. Results: Among 550 pyelonephritis patients, the prevalence of pyonephrosis was 60 (10.9%) (8.3-13.5, 95% Confidence Interval). The mean age was 54.62±12.14 years, and 41 (68.33%) were males. The most common clinical symptom was flank pain with or without fever in 46 (76.66%) patients. Escherichia coli was the most common offending organism in 20 (33.33%). Ultrasonography showed classical echogenic debris with floaters and internal echoes in 44 (73.33%) patients. Double J stenting was successfully done in 44 (73.33%) patients. Percutaneous nephrostomy was done in the remaining 16 (26.66%) patients. Conclusions: The prevalence of pyonephrosis in pyelonephritis is similar to previous studies done in similar settings. Keywords: pyelonephritis; pyonephrosis; kidneys.