ABSTRACT
Introduction: Emphysematous pyelonephritis (EPN) is a rare yet life threatening, necrotizing renal parenchymal infection with a mortality rate of 20-25%. With advent of CT, early goal directed therapy with antibiotics, aggressive treatment of sepsis and percutaneous drainage techniques, the mortality and morbidity rates are not as grim as earlier reports. Nephrectomy, treatment of the past has been replaced with nephron sparing surgery with better patient outcomes. A retrospective study was conducted at Government Kilpauk Medical College Hospital between January 2020 and April 2022. Diabetes, obstructive uropathy, structural abnormalities of the urinary tract and immunosuppression are well known risk factors for EPN. Malignancy and associated chemotherapy can make the vulnerable even more susceptible to EPN. The COVID19 pandemic, which was rampant for the past two years, with steroids being the cornerstone of management of COVID pneumonia also contributed to significant immunosuppression and poor glycemic control in many. This study wants to highlight along with traditional risk factors, the impact of COVID19 and Cancer on EPN. Methods: Demographic, clinical, radiological, and microbiological data of 33 patients were recorded. The data were analyzed to study risk factors, treatment modalities, need for hemodialysis, prognostic factors contributing to morbidity and mortality and patient outcome.The initial diagnosis of EPN at presentation was made by ultrasound evidence of gas in renal parenchyma, which was confirmed by CT imaging. Results: Out of a total 33 patients, 64% were females and the median age was 57.5 years. At presentation, common symptoms were abdominal pain (93%), renal angle tenderness (87%), fever (82%), vomiting (75%), dysuria (74%) and oliguria (65.9%). 81.8% (n=27) patients were diabetic. Urinary tract obstruction was present in 33.3% (n=11), Solid organ malignancy related EPN in 21.2% (n=7), with cancers involving kidney and urinary tract predominantly, concomitant COVID infection in 18.2% (n=6) patients, renal transplant EPN in 9% (n=3) of patients respectively. Most common organism was E.coli (60%) followed by Klebsiella spp.(10%), Pseudomonas (8%), Candida spp. (5.6%), Proteus mirabilis (1.4%) and culture negative EPN (15%). CT scoring was done by Huang and Tseng classification. Class I was documented in 28%, Class 2 in 58.8%, Class 3 in 11.8% and Class 4 in 2% of patients. DJ stenting was done in 55% of patients, percutaneous nephrostomy in 3% and the remaining patients improved with antibiotics alone. 35.7% (n=12) required dialysis,10.7% (n=4) were dialysis dependent at the end of three months with 9%(n=3) requiring dialysis indefinitely. Gender, glycemic status or uremic symptoms showed no statistical significance. Sepsis, shock, altered sensorium, higher serum creatinine and hemodialysis dependency had significant impact on patient's outcome. Conclusions: Early diagnosis and treatment with broad-spectrum antibiotics and properly timed interventions decreased mortality. Abdominal pain, renal angle tenderness and fever were the most common symptoms. E. coli was the commonest organism encountered. Solid organ malignancy contributed to a sizable portion of EPN in our study secondary to susceptibility to infections and obstruction. COVID19 infection is a risk factor for EPN due to worsening glycemic status and immunosuppression caused by steroid administration. No conflict of interest