Case Report Culture-Negative Bilateral Emphysematous Pyelonephritis Presented as Acute Renal Failure and Managed Medically Only Yalcin Solak, MD, Kultigin Turkmen, MD, Huseyin Atalay, MD, and Suleyman Turk, MD Abstract: Emphysematous pyelonephritis is a life-threatening infec- tion especially seen in patients with poorly-controlled diabetes mellitus. Imaging modalities (preferably computed tomography) are required to establish the diagnosis. Treatment modalities include volume resusci- tation, broad-spectrum antibiotics, percutaneous drainage, and, as a last resort, nephrectomy. We present a case of a 46-year-old female who had hypertension and type-2 diabetes mellitus and presented with com- plaints of dysuria, back pain, and decreased urine output. Renal ultra- sound and abdominal computerized tomography (CT) revealed air-fluid levels at each perirenal region and collecting systems, consistent with emphysematous pyelonephritis. Her clinical situation improved with vigorous fluid resuscitation and broad-spectrum antibiotic treatment. Key Words: acute renal failure, bilateral emphysematous pyelone- phritis, culture-negative E mphysematous pyelonephritis is a potentially fatal infec- tion; therefore, timely diagnosis and the initiation of treat- ment are of paramount importance. Diagnosis of emphyse- matous pyelonephritis can be difficult if it is solely based on clinical features. Demonstration of gas formation within or around the kidneys and collecting systems confirms the di- agnosis. The first line imaging modality in these cases is usually ultrasound, but computed tomography (CT) scan is the best imaging modality to both show the gas and accu- rately make the nephrologic classification. Treatment of em- physematous pyelonephritis depends on both the severity of the disease and patient comorbidities. Case Report A 46-year-old female patient with hypertension and type 2 diabetes mellitus was referred to our nephrology clinic with acute renal failure of unknown etiology, back pain, and dysuria. The patient had been evaluated at another center with complaints of flank and back pain, dysuria, and diminished urine output. She had undergone hemodialysis 5 times due to anuric acute renal failure. The patient had hypertension for 19 years and type 2 diabetes mellitus for 3 years. She was on oral antidiabetic agents, and she reported well controlled serum glucose levels. On admission at our clinic she was afebrile, blood pressure was 140/80 mm Hg, and heart rate was regular at 80 beats per minute. She de- nied any fevers, cough, headache, dyspnea, or edema. She never smoked or consumed alcohol. Physical examination was unremarkable except for bilateral flank tenderness. Ini- tial laboratory values were as follows: blood urea nitrogen: 75 mg/dL; creatinine: 1.8 mg/dL; sodium: 134 mEq/L; potassium: 3.4 mEq/L; albumin: 2.4 g/dL; calcium: (continued next page) From the Nephrology Department, Selcuk University, Meram School of Medicine, Meram, Konya, Turkey. Reprint requests to Yalcin Solak, MD, Nephrology Department, Selcuk Uni- versity, Meram School of Medicine, Meram, Konya, Turkey. Email: yalcinsolakmd@gmail.com Accepted March 9, 2009. Copyright © 2010 by The Southern Medical Association 0038-4348/0-2000/10300-0154 Key Points • Emphysematous pyelonephritis is a severe, potentially fatal necrotizing infection of renal parenchyma and perirenal tissues with gas-forming bacteria. • More than 90% of cases occur in diabetics with poor glycemic control. Other predisposing factors are uri- nary tract obstruction, polycystic kidneys, end stage renal disease, and immunosuppression. • Most of the time, imaging modalities, preferentially com- puted tomography, are needed to ascertain the diagnosis. • Treatment depends on the severity of the disease. In its mildest forms, broad spectrum antibiotics along with vig- orous hydration are appropriate treatment measures. In more severe cases, percutaneous drainage and medical therapy are appropriate. In the most severe cases, bilat- eral nephrectomy is performed as a last resort. 154 © 2010 Southern Medical Association