Volume 7, Number 35;  March 26, 2007 - Emphysematous Pyelonephritis

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Unique Identifier [PMID]: 16916776

Authors: Soo Park B. Lee SJ. Wha Kim Y. Sik Huh J. Il Kim J. Chang SG.

Institution: Department of Urology, School of Medicine, Kyung Hee University, Seoul, South Korea.

Title: Outcome of nephrectomy and kidney-preserving procedures for the treatment of emphysematous pyelonephritis.

Source: Scandinavian Journal of Urology & Nephrology. 40(4):332-8, 2006.

Abstract: OBJECTIVE: Emphysematous pyelonephritis (EPN) is an acute necrotizing infection of the kidney characterized by gas formation. In order to compare the outcome of nephrectomy and kidney-preserving procedures for the treatment of EPN we reviewed our experiences of EPN over the past 18 years. MATERIAL AND METHODS: The medical records of 17 patients with EPN treated between October 1986 and September 2004 were retrospectively reviewed. Abdominal X-ray and/or CT were used as diagnostic methods. RESULTS: Women outnumbered men (12 vs five), and all patients had diabetes. Obstruction of the corresponding reno-ureteral unit was found in one patient. Thirteen of the 17 patients (76%) had poorly controlled diabetes (hemoglobin A1c>7%). The diagnosis of EPN was confirmed by gas in the parenchymal or perinephric space as detected by abdominal X-ray or CT. Escherichia coli was the commonest organism present in urine cultures (52%), followed by Klebsiella pneumoniae (24%). Prompt efforts were made to control diabetes, and i.v. antibiotics were given. Nephrectomy was performed in 10 patients and nine patients survived (90% success rate). The success rate among those who received medical therapy only was 50% (2/4 patients). Percutaneous drainage was performed in three patients, two of whom survived (67% success rate). The overall mortality rate was 17.6% (3/17 patients). CONCLUSIONS: Immediate nephrectomy with glycemic control measures and antibiotic administration is crucial for the successful treatment of EPN. However, in inoperable cases, percutaneous drainage can be an effective treatment option.

Publication Type: Journal Article. Research Support, Non-U.S. Gov't.

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Unique Identifier [PMID]: 16129204

Authors: Tseng CC. Wu JJ. Wang MC. Hor LI. Ko YH. Huang JJ.

Institution: Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.

Title: Host and bacterial virulence factors predisposing to emphysematous pyelonephritis.

Source: American Journal of Kidney Diseases. 46(3):432-9, 2005 Sep.

Abstract: BACKGROUND: Emphysematous pyelonephritis (EPN) is a rare, severe, gas-forming infection of the kidney, and its precise pathogenesis remains obscure. METHODS: To investigate the roles of host and bacterial virulence factors in the pathogenesis of EPN, we compared: (1) host factors in patients with EPN (n = 47) with those in patients with acute renal infections without gas formation (non-EPN; n = 79), (2) the prevalence of virulence gene in causative Escherichia coli strains from 16 of the 47 EPN cases with all 79 non-EPN cases by means of polymerase chain reaction analysis, and (3) gas volumes produced by EPN and non-EPN strains cultured in broths at 3 glucose concentrations (100, 180, and 250 mg/dL [5.6, 10.0, and 13.9 mmol/L]). RESULTS: Diabetes mellitus (DM) with poor glycemic control (ie, hemoglobin A1c level > 11%) and urinary tract obstruction were more prevalent in the EPN group. However, DM with poor glycemic control was the only host factor independently associated with EPN (odds ratio, 4.9; P = 0.018). EPN strains had a greater prevalence of the uropathogenic-specific protein (usp) genes. Multivariate analyses also showed the association between usp and EPN with borderline significance (odds ratio, 8.4; P = 0.057). There was no significant difference in gas production by E coli isolated from patients with or without EPN. CONCLUSION: DM with poor glycemic control and urinary tract obstruction are host factors predisposing to EPN. There was no difference in gas production between EPN and non-EPN E coli strains. The distribution of E coli virulence genes was remarkably similar between the 2 groups. However, the PapG II adhesin (papG II) gene is significantly decreased and the usp gene is increased with borderline significance in EPN E coli strains.

Publication Type: Comparative Study. Journal Article. Research Support, Non-U.S. Gov't.

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Unique Identifier [PMID]: 10737279

Authors: Huang JJ. Tseng CC.

Institution: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan, Republic of China. jjhuang@mail.ncku.edu.tw

Title: Emphysematous pyelonephritis: clinicoradiological classification, management, prognosis, and pathogenesis.

Source: Archives of Internal Medicine. 160(6):797-805, 2000 Mar 27.

Abstract: BACKGROUND: Emphysematous pyelonephritis (EPN) is a rare, severe gas-forming infection of renal parenchyma and its surrounding areas. The radiological classification and adequate therapeutic regimen are controversial and the prognostic factors and pathogenesis remain uncertain. OBJECTIVES: To elucidate the clinical features, radiological classification, and prognostic factors of EPN; to compare the modalities of management (ie, antibiotic treatment alone, percutaneous catheter drainage combined with antibiotic treatment, or nephrectomy) and outcome among the various radiological classes of EPN; and to clarify the gas-forming mechanism and pathogenesis of EPN by gas analysis and pathological findings. PATIENTS AND METHODS: Forty-eight EPN cases from our institution were enrolled between August 1,1989, and November 30, 1997. According to the radiological findings on computed tomographic scan, they were classified into the following classes: (1) class 1: gas in the collecting system only; (2) class 2: gas in the renal parenchyma without extension to extrarenal space; (3) class 3A: extension of gas or abscess to perinephric space; class 3B: extension of gas or abscess to pararenal space; and (4) class 4: bilateral EPN or solitary kidney with EPN. The clinical manifestations, management, and outcome were compared. The gas contents of specimens from 6 patients were analyzed. The pathological findings from 8 patients who received nephrectomy were reviewed. The statistical methods consisted of the Fisher exact test (2 tailed) for categorical variables and Wilcoxon rank sum test for continuous variables to test the predictors of poor prognosis. RESULTS: Forty-six patients (96%) had diabetes mellitus, and 10 (22%) of the 46 also had urinary tract obstruction in the corresponding renoureteral unit. The other 2 nondiabetic patients (4%) had severe hydronephrosis. Twenty-one (72%) of the 29 patients with diabetes mellitus also had a glycosylated hemoglobin A(1c) level higher than 0.08. Escherichia coli (69%) and Klebsiella pneumoniae (29%) were the most common pathogens. The mortality rate in patients who received antibiotic treatment alone was 40% (2 of 5 patients). The success rate of management by percutaneous catheter drainage (PCD) combined with antibiotic treatment was 66% (27 of 41 patients). In classes 1 and 2 EPN, all the patients who were treated using a PCD or ureteral catheter combined with antibiotic treatment survived. In extensive EPN (classes 3 and 4), 17 (85%) of the 20 patients with fewer than 2 risk factors (ie, thrombocytopenia, acute renal function impairment, disturbance of consciousness, or shock) were successfully treated using PCD combined with antibiotic treatment; and the patients with 2 or more risk factors had a significantly higher failure rate than those with no or only 1 risk factors (92% vs 15%, P<.001). Eight of the 14 patients who had an unsuccessful treatment using a PCD underwent subsequent nephrectomy, 7 of whom survived. Only 2 patients were managed by direct nephrectomy and survived. The overall success rate of nephrectomy was 90% (9 of 10 patients). The total mortality was 18.8% (9 of 48 patients). Five of the 6 gas samples contained hydrogen (average, 12.8%), and all had carbon dioxide (average, 14.4%). The pathological findings from 8 of 10 who underwent nephrectomy revealed poor perfusion in most cases (ie, infarction, 5 patients; vascular thrombosis, 3 patients; and arteriosclerosis and/or glomerulosclerosis, 4 patients). CONCLUSION: Acute renal infection with E coli or K pneumoniae in patients with diabetes mellitus and/or urinary tract obstruction is the cornerstone for the development of EPN. Mixed acid fermentation of glucose by Enterobacteriaceae is the major pathway of gas formation. For localized EPN (classes 1 and 2), PCD combined with antibiotic treatment can provide a good outcome. (ABSTRACT TRUNCATED)

Publication Type: Journal Article.

Resident Report / Department of Medicine & Grady Branch Library

Emory University School of Medicine

2006 Edition

Participating Faculty:  Carlos Del Rio MD  / Joyce Doyle MD / Lorenzo Difrancesco MD / Joel Mermis MD / Maunank Shah MD

Contact: Karl Woodworth