A novel mortality risk score for emphysematous pyelonephritis: A multicenter study of the Global Research in the Emphysematous Pyelonephritis group

Abstract

Background: Emphysematous pyelonephritis (EPN) is a necrotizing infection of the kidney and the surrounding tissues associated with considerable mortality. We aimed to formulate a score that classifies the risk of mortality in patients with EPN at hospital admission.

Materials and methods: Patients diagnosed with EPN between 2013 and 2020 were retrospectively included. Data from 15 centers (70%) were used to develop the scoring system, and data from 7 centers (30%) were used to validate it. Univariable and multivariable logistic regression analyses were performed to identify independent factors related to mortality. Receiver operating characteristic curve analysis was performed to construct the scoring system and calculate the risk of mortality. A standardized regression coefficient was used to quantify the discriminating power of each factor to convert the individual coefficients into points. The area under the curve was used to quantify the scoring system performance. An 8-point scoring system for the mortality risk was created (range, 0-7).

Results: In total, 570 patients were included (400 in the test group and 170 in the validation group). Independent predictors of mortality in the multivariable logistic regression were included in the scoring system: quick Sepsis-related Organ Failure Assessment score ≥2 (2 points), anemia, paranephric gas extension, leukocyte count >22,000/μL, thrombocytopenia, and hyperglycemia (1 point each). The mortality rate was <5% for scores ≤3, 83.3% for scores 6, and 100% for scores 7. The area under the curve was 0.90 (95% confidence interval, 0.84-0.95) for test and 0.91 (95% confidence interval, 0.84-0.97) for the validation group.

Conclusions: Our score predicts the risk of mortality in patients with EPN at presentation and may help clinicians identify patients at a higher risk of death.

Keywords

Emphysematous pyelonephritis / Mortality / Prognosis

Author summay

H.T.-S. and J.I.R.-T. contributed equally and share first authorship.

Acknowledgments

None.

Statement of ethics

Ethics committee approval was obtained from the leading center, Department of Urology, Hospital Israelita Albert Einstein, BP-a Beneficência Portuguesa de São Paulo, Sao Paulo, Brazil (5.192.573). All patients signed an informed consent in this study. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Conflict of interest statement

No conflict of interest has been declared by the authors

Funding source

None.

Author contributions

HT-S, JIR-T, JY-CT, YT, VG: Protocol/project development;

JGC-S, EIB-C, SK, JES-N, JEE-A, DR, SBH, OTA, CPT-C, AS, MAL, MCC-B, LGV-L, BK, HYT, JGA-H, LSG-G, UK, JABA-B, JJ, CA, FV-G, SA, HOD-S, CCA, WSY: Data collection and management;

HT-S, JIR-T, JY-CT, YT, DC, VG, MLW: Data analysis and interpretation;

JIR-T, JY-CT, YT, DC, VG, MLW: Manuscript writing/editing.

Data availability

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

References

[1] Abdul-Halim H, Kehinde EO, Abdeen S, Lashin I, Al-Hunayan AA, Al-Awadi KA. Severe emphysematous pyelonephritis in diabetic patients: Diagnosis and aspects of surgical management. Urol Int 2005; 75(2):123-128.

[2] Olvera-Posada D, Armengod-Fischer G, Vázquez-Lavista LG, et al. Emphysematous pyelonephritis: Multicenter clinical and therapeutic experience in Mexico. Urology 2014; 83(6):1280-1284.

[3] Arrambide-Herrera JG, Robles-Torres JI, Ocaña-Munguía MA, Romero-Mata R, Gutiérrez-González A, Gómez-Guerra LS. Predictive factors for mortality and intensive care unit admission in patients with emphysematous pyelonephritis: 5-year experience in a tertiary care hospital. Actas Urol Esp (Engl Ed) 2022; 46(2):98-105.

[4] Yap XH, Ng CJ, Hsu KH, et al. Predicting need for intensive care unit admission in adult emphysematous pyelonephritis patients at emergency departments: Comparison of five scoring systems. Sci Rep 2019; 9(1):16618.

[5] Krishnamoorthy S, Zumla A, Sekar H, Muneer A, Thiruvengadam G, Kumaresan N. Prognostic scoring system and risk stratification in patients with emphysematous pyelonephritis: An 11-year prospective study at a tertiary referral centre. BJU Int 2021; 127(4):418-427.

[6] Riley LK, Rupert J. Evaluation of patients with leukocytosis. Am Fam Physician 2015; 92(11):1004-1011.

[7] Franchini M, Veneri D, Lippi G. Thrombocytopenia and infections. Expert Rev Hematol 2017; 10(1):99-106.

[8] Cappellini MD, Motta I. Anemia in clinical practice-definition and classification: Does hemoglobin change with aging? Semin Hematol 2015; 52(4):261-269.

[9] Delanaye P, Cavalier E, Pottel H. Serum creatinine: Not so simple! Nephron 2017; 136(4):302-308.

[10] Shakya A, Chaudary SK, Garabadu D, Bhat HR, Kakoti BB, Ghosh SK. A comprehensive review on preclinical diabetic models. Curr Diabetes Rev 2020; 16(2):104-116.

[11] Singer M, Deutschman CS, Seymour C, et al. The third international consensus definitions for sepsis and septic shock (sepsis-3). JAMA 2016; 315(8):801-810.

[12] Huang JJ, Tseng CC. Emphysematous pyelonephritis: Clinicoradiological classification, management, prognosis, and pathogenesis. Arch Intern Med 2000; 160(6):797-805.

[13] Al-Geizawi SM, Farney AC, Rogers J, et al. Renal allograft failure due to emphysematous pyelonephritis: Successful non-operative management and proposed new classification scheme based on literature review. Transpl Infect Dis 2010; 12(6):543-550.

[14] Hsueh PR, Ko WC, Wu JJ, et al. Consensus statement on the adherence to Clinical and Laboratory Standards Institute (CLSI) Antimicrobial Susceptibility Testing Guidelines (CLSI-2010 and CLSI-2010-update) for Enterobacteriaceae in clinical microbiology laboratories in Taiwan. J Microbiol Immunol Infect 2010; 43(5):452-455.

[15] Klatte T, Gallagher KM, Afferi L, et al. The VENUSS prognostic model to predict disease recurrence following surgery for non-metastatic papillary renal cell carcinoma: Development and evaluation using the ASSURE prospective clinical trial cohort. BMC Med 2019; 17(1):182.

[16] Tang HJ, Li CM, Yen MY, et al. Clinical characteristics of emphysematous pyelonephritis. J Microbiol Immunol Infect 2001; 34(2):125-130.

[17] Khaira A, Gupta A, Rana DS, Gupta A, Bhalla A, Khullar D. Retrospective analysis of clinical profile prognostic factors and outcomes of 19 patients of emphysematous pyelonephritis. Int Urol Nephrol 2009; 41(4):959-966.

[18] Huang JJ, Chen KW, Ruaan MK. Mixed acid fermentation of glucose as a mechanism of emphysematous urinary tract infection. J Urol 1991; 146(1):148-151.

[19] Ubee SS, McGlynn L, Fordham M. Emphysematous pyelonephritis. BJU Int 2011; 107(9):1474-1478.

[20] Schainuck LI, Fouty R, Cutler RE. Emphysematous pyelonephritis. A new case and review of previous observations. Am J Med 1968; 44(1):134-139.

[21] Falagas ME, Alexiou VG, Giannopoulou KP, Siempos II. Risk factors for mortality in patients with emphysematous pyelonephritis: A meta-analysis. J Urol 2007; 178(3 Pt1):880-885.

[22] Lu YC, Chiang BJ, Pong YH, et al. Predictors of failure of conservative treatment among patients with emphysematous pyelonephritis. BMC Infect Dis 2014;14:418.

[23] Michaeli J, Mogle P, Perlberg S, Heiman S, Caine M. Emphysematous pyelonephritis. J Urol 1984; 131(2):203-208.

[24] Langston CS, Pfister RC. Renal emphysema. A case report and review of the literature. Am J Roentgenol Radium Therapy, Nucl Med 1970; 110(4):778-786.

[25] Wan YL, Lo SK, Bullard MJ, Chang PL, Lee TY. Predictors of outcome in emphysematous pyelonephritis. J Urol 1998; 159(2):369-373.

[26] Aswathaman K, Gopalakrishnan G, Gnanaraj L, Chacko NK, Kekre NS, Devasia A. Emphysematous pyelonephritis: Outcome of conservative management. Urology 2008; 71(6):1007-1009.

[27] Gill TM. The central role of prognosis in clinical decision making. JAMA 2012; 307(2):199-200.