Predictive factors of pyonephrosis in renal calculus patients

Abstract

BACKGROUND: This is a retrospective study conducted to describe the prevalence and analyse the predictive factors of patients with underlying renal calculi presenting with pyonephrosis in Hospital Universiti Sains Malaysia.

METHODS: Patients with renal calculus disease with or without pyonephrosis presenting to Hospital Universiti Sains Malaysia between January 2009 and October 2020 were evaluated. Analysis of the data was done using both univariate and multivariate analysis.

RESULTS: The prevalence of pyonephrosis from 1st January 2009 to 31st October 2020 was 120 of which 100 (83.3%) were secondary to renal calculus. A total of 139 renal calculus patients were included with 72 renal calculus patients without pyonephrosis and 67 renal calculus patients with pyonephrosis. The positive predictive factors amongst patients with renal calculus for developing pyonephrosis include diabetes mellitus (p = 0.038), non-functioning kidney (p = 0.022), staghorn calculi (p = 0.046) and moderate or severe hydronephrosis (p = 0.013). In terms of long term outcomes, 3.1% (2/65) patients passed away from urosepsis secondary to pyonephrosis and 12.3% (8/65) developed acute kidney injury (AKI) and progressed to chronic kidney disease (CKD).

CONCLUSION: Our study demonstrates out of a total of 338 patients who presented to HUSM with renal calculus, a prevalence of 120 patients (35.5%) across 11 years for pyonephrosis out of which 100 patients (83.3%) were renal calculus patients who developed pyonephrosis. Factors showing statistically significant associations with the development of pyonephrosis include diabetes mellitus (p = 0.024), non-functioning kidney on admission (p = 0.02), presence of staghorn calculi (p = 0.043) and moderate or severe hydronephrosis (p = 0.013).