emphysematous pyelonephritis in a renal “>Case Report

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American Journal of Emergency Medicine

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Emphysematous pyelonephritis in a renal allograft

Abstract

Emphysematous pyelonephritis (EPN) is a necrotizing infection characterized by the presence of gas in the renal parenchyma, collecting system, and surrounding structures. It is a rare, life-threatening disease, which poses a diagnostic challenge due to its rarity and nonspecific pre- sentation. EPN can affect both native and allograft kidneys and is often treated surgically. In this report, we describe a patient with EPN in a renal allograft who was treated conservatively with intravenous antibi- otics without percutaneous drainage or nephrectomy.

Emphysematous pyelonephritis (EPN) is a necrotizing infection characterized by the presence of gas in the renal parenchyma, collecting system, and surrounding structures [1,2]. It is a rare, life-threatening disease, which poses a diagnostic challenge due to its rarity and nonspe- cific presentation [3]. EPN can affect both native and allograft kidneys and is often treated surgically [4,5]. In this report, we describe a patient with EPN in a renal allograft who was treated conservatively with intra- venous (IV) antibiotics without percutaneous drainage or nephrectomy. A 61-year-old man came to the emergency department after experienc- ing 3 days of progressively worsening lethargy, shortness of breath, and nonproductive cough. His history was significant for living donor renal transplant, diabetes mellitus, and hypertension. At triage, his vital signs were as follows: blood pressure, 176/86 mm Hg; heart rate, 145 beats per minute; respiratory rate, 32 breaths per minute; and temperature, 40.7?C. On examination, he appeared ill, with tachycardia, tachypnea, and dry mu-

cous membranes. He had a soft, nontender abdomen.

Laboratory studies demonstrated the following values: blood glucose, 518 mg/dL; bicarbonate, 15 mEq/L; lactic acid, 7.2 mg/dL; creatinine, 6.2 mg/dL; white blood cell count, 14.4 x 10³/uL; anion gap, 22 mEq/L, and pyuria–findings consistent with acute kidney injury, diabetic ketoacidosis, and sepsis due to a urinary source. Noncontrast computed tomography scan of his abdomen revealed numerous foci of gas within the parenchyma of the upper and medial lower poles of the transplanted kidney, diffuse thickening of the bladder wall, and pericystic soft tissue stranding (Fig. 1A and B). EPN was diagnosed, and a transplant surgeon was consulted.

Treatment in the emergency department consisted of aggressive IV fluid resuscitation with initiation of an insulin drip. After urine and blood samples were obtained, the patient was started on vancomycin and piper- acillin/tazobactam. Despite this treatment, he became persistently hypoten- sive and required norepinephrine infusion. The patient was admitted to the intensive care unit, where the treatment team continued the antibiotics and elected not to remove the transplanted kidney. The findings of diabetic ketoacidosis also improved with medical management. At the time of discharge, the patient had adequate urine output, and his creatinine had improved to 3.2. He was discharged to a subacute rehabilitation facility 16 days after initial presentation.

EPN is a life-threatening process that can progress to sepsis, shock, and multiple organ failure, with a mortality rate of 40% to 50% [6]. It has a female-to-male ratio of 4 to 1 [2,3,7]. Multiple factors are thought to con- tribute to its pathogenesis, including elevated levels of glucose in renal tis- sues, immunosuppression, urinary tract obstruction, and impaired vascular supply [7]. Diabetes is almost universally present in patients with EPN [2,8]. EPN is typically caused by gas-producing bacteria such as Escherichia coli and Klebsiella pneumonia [9]. Diagnosis can be challenging because of the nonspecific symptomatology and laboratory findings. Physical ex- amination findings are nonspecific and unreliable; therefore, EPN is usually diagnosed by imaging [5]. Computed tomography is superior to ultrasonography in establishing the presence of gas-producing infec- tion in the kidneys. Renal ultrasonography as a stand-alone test can

miss the presence of gas in the urinary system [6,9].

Treatment of EPN in a renal allograft is controversial. The treating team must weigh the preservation of transplanted kidney against potentially in- creasing the risk of death by allowing the affected organ to remain [2]. Few treatment algorithms have been published [10]. In 2000, Huang and Tseng

[2] published a classification system based on the extension of gas into the patient’s renal parenchyma, as seen on CT imaging. They recommended es- calation of treatment including nephrectomy as the radiographic findings of EPN advanced. In 2010, Al-Geizawa et al [4] developed a similar classifica- tion system for patients with renal allografts affected by EPN based on the extent of renal gas formation on CT imaging and other clinical factors. As with Huang and Tseng, patients were stratified into groups based on dis- ease severity, with corresponding treatment recommendations ranging from antibiotics alone to radical nephrectomy [4].

In this report, we describe a patient with EPN in a renal allograft who was treated conservatively with IV antibiotics without percutaneous drainage or nephrectomy. Emergency physicians must have a low threshold for pursuing advanced imaging in transplant patients whose presentation suggests EPN because of their increased risk of infection

Fig. 1. CT scan of the patient’s abdomen.

0735-6757/(C) 2016

and unreliable physical examination findings [2,7]. CT can be used to confirm the diagnosis and to determine optimal management ap- proaches for native and transplanted kidneys [2,4]. After the diagnosis is made, the emergency physician should focus on patient stabilization, initiation of broad-spectrum antibiotics, consultation with appropriate subspecialties, and coordination of care between medical and surgical subspecialties for hospital admission.

Acknowledgments

The authors thank Linda J. Kesselring, MS, ELS, the technical editor/ writer in the Department of Emergency Medicine at the University of Maryland School of Medicine, for her copyediting of the manuscript.

Andrew J. Crouter, MD Michael K. Abraham, MD

R. GentryWilkerson, MD*

Department of Emergency Medicine, University of Maryland School of

Medicine, Baltimore, MD

?Corresponding author at: Department of Emergency Medicine University of Maryland School of Medicine, 110 S Paca St, 6th Floor, Suite 200, Baltimore, MD 21201. Tel.: +1 410 328 8025 E-mail address: [email protected]

http://dx.doi.org/10.1016/j.ajem.2016.09.043

References

1. Tienza A, Hevia M, Merino I, Velis JM, Algarra R, Pascual JI, et al. Case of emphysema- tous pyelonephritis in kidney allograft: conservative treatment. Can Urol Assoc J 2014;8:E256-9.
2. Huang JJ, Tseng CC. Emphysematous pyelonephritis; clinicoradiological classifica- tion, management, prognosis, and pathogenesis. Arch Intern Med 2000;160: 797-805.
3. Agreda Castaneda F, Lorente D, Trilla Herrera E, Gasanz Serrano C, Servian Vives P, Iztueta Saavedra I, et al. Extensive emphysematous pyelonephritis in a renal allograft: case report and review of literature. Transpl Infect Dis 2014;16:642-7.
4. Al-Geizawa SM, Farney AC, Rogers J, Assimos D, Requarth JA, Doares W, et al. Renal alloGraft failure due to emphysematous pyelonephritis: successful non-operative management and proposed new classification scheme based on literature review. Transpl Infect Dis 2010;12:543-50.
5. Schmidt S, Foert E, Zidek W, van der Giet M, Westhof TH. Emphysematous pyelone- phritis in a kidney allograft. Am J Kidney Dis 2009;53:895-7.
6. Tsu JH, Chan CK, Chu RW, Law IC, Kong CK, Liu PL, et al. Emphysematous pyelone- phritis: an 8-year retrospective review across four acute hospitals. Asian J Surg 2013;36:121-5.
7. Kangjam SM, Irom KS, Khumallambam IS, Sinam RS. Role of conservative manage- ment in emphysematous pyelonephritis–a retrospective study. J Clin Diagn Res 2015;9:PC09-11.
8. Arai S, Makino T, Okugi H, Hasumi M, Shibata Y, Hatori M, et al. A case of emphyse- matous pyelonephritis in a renal allograft. Transplantation 2006;81:296-7.
9. Uruc F, Yuksel OH, Sahin A, Urkmez A, Yildirim C, Verit A. Emphysematous py- elonephritis: our experience in managing these cases. Can Urol Assoc J 2015; 9:E480-3.
10. Bansal RK, Lambe S, Kapoor A. Emphysematous pyelonephritis in failed renal allo- graft: case report and review of literature. Urol Ann 2016;8:111-3.