Emphysematous pyelonephritis: Does a standard management algorithm and a prognostic scoring model optimize patient outcomes?

Objective: The objective of the study is to analyze the risk factors determining the outcomes of patients with emphysematous pyelonephritis (EPN) by the adoption of a standardized management algorithm as well as to develop a prognostic scoring model to risk stratify these patients. Materials and Methods: The hospital records of 72 consecutive patients with EPN from February 2012 to January 2018 were retrospectively reviewed. Demographic, clinicoradiographic, and laboratory characteristics were recorded. Patients were managed with a standard management protocol and based on outcomes divided into three groups. Group I survived with conservative management, Group II survived after emergency nephrectomy, and Group III expired. The risk factors for nephrectomy and mortality were analyzed. Results: The mean age was 53 years. Male to female ratio was 4:5. There were 61 (84.7%), 4 (5.6%), and 7 (10%) patients in Groups I, II, and III, respectively. Diabetes mellitus was the most common comorbidity detected in 62 (86%) of patients. Type II EPN was the most common radiological presentation observed in 32 (44%) patients. Overall survival rate was 90%, and kidney salvage rate was 80%. Escherichia coli was the most common organism isolated. Thirty-two (45%) patients exhibited resistance to third-generation cephalosporin antibiotics. Thrombocytopenia, low body mass index (BMI), presence of >2 comorbidities, high total leukocyte count (TLC), and hypoalbuminemia were significantly associated with mortality. On adoption of the prognostic scoring system, mortality rates according to the risk subgroups were as follows: favorable - 0%, intermediate - 19%, and poor - 100%. Conclusion: Conservative management adopting appropriate algorithm reduces mortality and avoids unnecessary emergency nephrectomies. Thrombocytopenia, low BMI, presence of >2 comorbidities, high TLC, and hypoalbuminemia were significantly associated with mortality.