P0298EMPHYSEMATOUS PYELONEPHRITIS: SEVEN YEAR EXPERIENCE OF MANAGING CONSECUTIVE 22 PATIENTS IN A SINGLE CENTER OF BANGLADESH
Authors: Rahim Muhammad Abdur , Jahan Ishrat , Habib Samira Humaira , Chowdhury Tufayel Ahmed , Ananna Mehruba Alam , Billah Md Mostarshid , Latif Abdul , Rahman Md Anisur , Iqbal Sarwar , Uddin Khwaja Nazim , Latif Zafar Ahmed 
Published: June 2020

Abstract

Background and Aims
Emphysematous pyelonephritis (EPN) is an uncommon, severe, necrotizing infection of the renoureteral unit and is recognized by accumulation of gas within the collecting system, renal parenchyma and/or perinephric tissue. Common risk factors for EPN are diabetes mellitus, renal stone, obstructive uropathy and immunosuppression. Principles of treatment include resuscitative measures, antibiotics, strict glycaemic control and interventions in selected cases. This study aimed to describe clinical, laboratory and imaging characteristics of EPN patients with special emphasis on in-hospital outcome.

Method
This cross-sectional study included consecutive 22 EPN patients, managed in the Department of Internal Medicine and the Department of Nephrology of a tertiary care hospital in Dhaka, Bangladesh from January 2013 to December 2019. Patients’ selected socio-demographic, clinical and laboratory parameters and in-hospital treatment-outcome were recorded in case record forms at the time of discharge or death, if were any.

Results
Total patients were 22 (mean age 46.8±12.5, range 34.0–55.0 years) including 16 (72.7%) females. All (22, 100%) were diabetic [one (4.5%) patient was newly detected as diabetic during EPN diagnosis]. Three (13.6%) patients had renal stones (bilateral in one), two (9.1%) had obstructive uropathy, six (27.3%) had chronic kidney disease, 12 (54.5%) had hyponatreamia and 16 (72.7%) were complicated by acute kidney injury (AKI). Patients presented with fever (22, 100%), loin pain/renal angle tenderness (19, 86.4%), vomiting (19, 86.4%) and dehydration (8, 36.4%). One (4.5%) patient had pneumaturia. One (4.5%) patient presented with uraemic encephalopathy and none had shock. One (4.5%) patient had tender ectopic (pelvic) right kidney. Patients had leukocytosis (mean total white cells 19917±7549, range 10250–37630/cmm of blood) and four (18.2%) patients had thrombocytopaenia. All patients had high erythrocyte sedimentation rate (mean 65.7±20.8, range 35–120 mm in 1st h) and C-reactive protein (mean 68.9±60.3, range 18–209 mg/L). Glycaemic status was poor [mean random blood glucose at admission 17.4±6.0, range 10.6–35.5 mmol/L and mean glycated haemoglobin (HbA1c) 9.8±2.1, range 6.9–15.5%]. Diagnosis of EPN was confirmed by abdominal ultrasonography and computed tomography scan. One patient had EPN in ectopic right kidney, one patient had EPN along with air in ureter, two patients had associated emphysematous cystitis and one had psoas abscess. Ten (45.5%) patients had EPN in right kidney (including pelvic kidney), 11 (50%) had EPN in left kidney, one (4.5%) had bilateral EPN and three (13.6%) patients had concomitant contralateral pyelonephritis. According to Huang and Tseng classification, one (4.5%) patient had class 4 EPN, three (13.6%) patients had class 3B, five (22.7%) patients had class 3A and thirteen (59.1%) patients had class 2 EPN. Escherichia coli was the most common (13, 59.1%) organism identified on urine culture [including four (4/13, 30.8%) cases with extended-spectrum beta-lactamase positive E. coli] and four (18.2%) patients were complicated by bacteraemia. Five (22.7%) patients required surgical interventions [nephrectomy in three (13.6%) and open drainage in two (9.1%)]. All patients were treated with intravenous antibiotics and other supportive measures. One patient required three sessions of haemodialysis. Mean hospital stay was 16.1±6.4 (range 7–31) days. AKI resolved in 3 (3/16, 18.8%) patients and in others renal function was improving at the time of discharge and there was no death.

Conclusion
Most EPN patients were successfully managed by conservative approach in this study, two-thirds had AKI, one-fourth required surgical interventions and there was no death. Though conservative approaches for managing EPN is becoming popular, we emphasize interventions should not be delayed, as and when indicated, and may appear life-saving.