Clinical Profile, Prognostic Indicators, and Outcomes in Patients with Acute Pyelonephritis: Comparing Emphysematous...

Emphysematous pyelonephritis (EPN) is a life-threatening necrotizing infection of the upper urinary tract, resulting in high morbidity and mortality. Comparative data between EPN and non-EPN are scarce, especially from developing countries.

To compare the clinical profile, prognostic indicators, management strategies, and outcomes in patients with emphysematous and nonemphysematous acute pyelonephritis (APN).

This was a prospective observational study conducted in a tertiary care teaching institute in North India from March 2022 to December 2025 and included 120 consecutive adult patients with APN. Radiological imaging was used to classify patients as EPN or non-EPN.

Of the 120 patients, 99 (82.5%) had non-EPN and 21 (17.5%) had EPN. The most common comorbidity was diabetes mellitus (75.0%) and was associated more frequently with EPN (95.2% vs. 70.7%, P = 0.024). Uncontrolled glycemia (glycosylated hemoglobin: >7.5%) was present in 67.5% of patients and significantly associated with EPN (P = 0.047). Escherichia coli was the most common pathogen found in urine (43.7%) and blood (62.5%) cultures. Radiological or surgical interventions were needed in 56.7% of patients, and renal replacement therapy and intensive care admission were needed in 34.2% and 22.5%, respectively. Mortality was higher in the EPN group than in the non-EPN group (14.3% vs. 3.0%; P = 0.066).

EPN is the severest form of APN and is associated with worse glycemic control, increased requirement for invasive procedures, and higher in-hospital mortality. Early diagnosis, prompt imaging, appropriate antimicrobial therapy, and timely multidisciplinary management are essential to improve clinical outcome.