UMEM Educational Pearls

Category: Visual Diagnosis

Title: What's the Diagnosis? Case by Dr. Siamak Moayedi

Posted: 5/5/2013 by Haney Mallemat, MD (Emailed: 5/6/2013) (Updated: 5/6/2013)
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38 year-old male with a past medical history of diabetes presents with back pain and hypotension. CT scan is shown below. What's the diagnosis?



Emphysematous Pyelonephritis (EPN)

EPN is a necrotizing infection of the renal and peri-nephric tissues with accumulation of gas within the tissues and collecting system of the kidney; it is rapidly fatal if not recognized and aggressively treated early.

Risk factors include an immunocompromised host; Diabetics are at particularly increased risk.

The most common etiologic organisms are Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa. Infection with anaerobic species is relatively uncommon.

In addition to the classic signs / symptoms of pyelonephritis, (e.g., flank pain, fever, pyuria, etc.), patients presenting with EPN may experience the passage of air in the urine (pneumaturia) or crepitus over their flank.

Abdominal CT scan is the diagnostic test of choice when clinical presentation and laboratory tests are suggestive (see below)

Treatment should include:

  • Aggressive resuscitation with fluids and vasopressors, as necessary
  • Broad-spectrum antibiotics
  • Percutaneous ureteral drain or stent placement, if obstruction is present


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