Risk factors of renal failure and severe complications in patients with emphysematous pyelonephritis-a single-center 15-year experience

Introduction: Emphysematous pyelonephritis (EPN) is a rare but severe infection of renal parenchyma. Risk factors of renal failure in patients survived from EPN are not clear. Methods: The authors retrospectively reviewed the patients with a diagnosis of EPN at Taipei Veterans General Hospital from January 1, 1995, to December 31, 2009. The authors analyzed the demographic, characteristics and the treatment modalities of those patients. The renal function of survivors after EPN episode had been followed for 1 year. Results: A total of 23 patients with a mean age of 62.8 ± 17.1 years were enrolled. Mean hospital duration was 31.8 ± 21.6 days. Fifteen (65.2%) patients had a history of diabetes mellitus. Mean serum HbA1c level among the diabetic patients was 11.7 ± 3.3. More than half of patients had Escherichia coli in culture. Eleven (47.8%) patients received antibiotic treatment alone. Twelve (52.2%) patients received the concurrent percutaneous drainage and antibiotics. The overall mortality rate was 8.6%. Shock, long hospital duration and the extensive classes of computed tomography image were correlated with poor outcome. A higher initial serum creatinine level (2.8 ± 1.4 versus 1.6 ± 0.8, P = 0.015) and receiving invasive therapy (67.7% versus 12.5%, P = 0.017) significantly contributed to chronic kidney disease in the follow-up. Shock is also an independent predictor of the poor outcome in those patients (P = 0.026). Conclusions: In the current era, antibiotics alone provide a high success rate for the treatment of EPN. Invasive therapy is a predictor of development of chronic kidney disease. Initial resuscitation and antibiotic therapy are still the cornerstone and have the benefit of the preservation of renal function.