Emphysematous Pyelonephritis (EPN) Treatment & Management

Updated: Nov 13, 2017
  • Author: Sugandh Shetty, MD, FRCS; Chief Editor: Edward David Kim, MD, FACS  more...
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Treatment

Approach Considerations

Patients with emphysematous pyelonephritis (EPN)  are extremely ill and need resuscitative measures in the intensive care unit, including oxygen, intravenous (IV) fluids, and correction of acid-base imbalances, along with glycemic control. Systolic blood pressure should be maintained above 100 mm Hg, with fluid or inotropic support if required. [6] Surgical intervention should be performed only after stabilization of the cardiorespiratory status

Prompt initiation of empiric IV antibiotic therapy is critical. The regimen chosen should be broad spectrum, primarily target gram-negative bacteria, and take into account individual patient characteristics and local patterns of antibiotic resistance. [10]

Although emergency nephrectomy has historically been the preferred treatment for EPN, a nephron-sparing approach is increasingly favored. [21, 22, 23, 24, 25, 26, 27, 28] Conservative treatment using percutaneous drainage with antibiotics is indicated as follows:

  • Patients with compromised renal function

  • Early cases associated with gas in the collecting system alone and patient is in otherwise in stable condition

  • Class 1 and class 2 EPN

  • Class 3 and class 4 EPN - In the presence of fewer than 2 risk factors (eg, thrombocytopenia, elevated serum creatinine levels, altered sensorium, shock)

Huang and Tseng reported a 66% success rate with percutaneous drainage and antibiotics in patients with EPN, while Aswathaman et al found an 80% success rate. [21] Huang and Tseng also reported a 90% success rate in patients who underwent nephrectomy. The use of nephrectomy is indicated as follows:

  • Treatment of choice for most patients

  • No access to percutaneous drainage or internal stenting (after patient is stabilized)

  • Gas in the renal parenchyma or "dry-type" EPN

  • Possibly bilateral nephrectomy in patients with bilateral EPN

  • Class 3 and class 4 EPN - In the presence of two or more risk factors (eg, thrombocytopenia, elevated serum creatinine, altered sensorium, shock)

A case report and literature review by Nana et al suggests that ureteric involvement may also be an indication for nephrectomy. [29]

The diagram below outlines the management of EPN.

Algorithm for the management of emphysematous pyel Algorithm for the management of emphysematous pyelonephritis.
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Antibiotic Therapy

Optimal antibiotic therapy for emphysematous pyelonephritis (EPN) has not been fully delineated, but empiric regimens should be broad spectrum, primarily target gram-negative bacteria, and take into account individual patient characteristics and local patterns of antibiotic resistance. [10] Recommendations in the literature vary: for example, Ubee et al suggest aminogycosides, β-lactamase inhibitors, cephalosporins, and fluoroquinolones, with the selection guided by local hospital policy. [6]

A study from Taiwan by Lu et al reported high rates of resistance to ampicillin and fluoroquinolones and moderate resistance to gentamicin. These authors recommend a third-generation or fourth-generation cephalosporin (eg, ceftazidime) for initial single-agent empirical therapy in most cases, but prefer carbapenem in patients with a history of prior hospitalization and antibiotic use, need for emergency hemodialysis, or presence of disseminated intravascular coagulation, which are risk factors for resistance to third-generation cephalosporins [10] .

Overall, Lu et al recommend tailoring initial therapy according to the classification system of Huang and Tseng (see Workup/Radiologic Classification) and risk factors for resistance, as follows [10] :

  • Class 1 – A third-generation cephalosporin, with or without amikacin, plus percutaneous catheter drainage in patients with obstructive uropathy
  • Class 2, 3, and 4 without risk factors –  A third-generation cephalosporin, with or without amikacin, plus percutaneous catheter drainage
  • Class 2, 3, and 4 with risk factors – Carbapenem with or without vancomycin plus percutaneous catheter drainage
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Percutaneous Drainage and Other Conservative Management

In an analysis of 48 cases, Huang and Tseng concluded that class 1 and class 2 EPN could be managed with percutaneous drainage and antibiotics. [4] This approach could also be used in patients with class 3 or 4 EPN who have fewer than two risk factors (eg, thrombocytopenia, elevated serum creatinine levels, altered sensorium, shock). However, in the presence of two or more risk factors, nephrectomy (discussed below) yielded better results. Sharma et al also experienced success with conservative management, but early diagnosis was important. [22]

Any obstruction found on imaging studies should be relieved with either percutaneous drainage or stent placement. Definitive treatment for stones should be deferred until later. The decision regarding the use of percutaneous drainage versus a double-J stent probably depends on the patient's condition. [23] Placement of a stent requires mild sedation or general anesthesia, whereas a percutaneous procedure can be performed with only a local anesthetic.

In cases of bilateral EPN or in cases of EPN in a solitary kidney, percutaneous drainage has been useful. EPN with gas in the collecting system alone or gas and fluid in the perinephric space may respond well to percutaneous drainage.

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Nephrectomy

Nephrectomy is the treatment of choice in most patients with emphysematous pyelonephritis (EPN). However, patients with EPN are extremely ill and need resuscitative measures in the intensive care unit. Surgical intervention should be performed only after stabilization of the cardiorespiratory status. A retroperitoneal flank incision is the preferred approach to avoid peritoneal contamination.

Gas in the renal parenchyma or dry-type EPN should be treated immediately with nephrectomy. Bilateral nephrectomy may be necessary in patients with bilateral EPN. Mortality rates were 15-20% in 2 series in which nephrectomy was the treatment of choice in EPN, while in a study by Huang and Tseng, nephrectomy had a 10% mortality rate. [4, 24, 30]

Nephrectomy complications include injury to the colon, duodenum, and great vessels. Postoperative wound infection is common, because wound healing in these patients is compromised.

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