eMedicine Specialties > Urology > Infections and Related Inflammatory Conditions

Emphysematous Pyelonephritis: Workup

Author: Sugandh Shetty, MD, Consulting Staff, Department of Urology, William Beaumont Hospital
Contributor Information and Disclosures

Updated: May 1, 2008

Workup

Laboratory Studies

  • A high index of suspicion is important when attempting to diagnose emphysematous pyelonephritis (EPN) promptly.
  • Laboratory data reveal leukocytosis with a left shift, pyuria, infected urine, thrombocytopenia, an elevated creatinine level, and positive blood culture results.
  • Patients with urosepsis and shock should undergo cardiac and pulmonary function assessment as needed.

Imaging Studies

  • Patients should be stabilized with intravenous fluids and intravenous antibiotics prior to radiologic intervention.
  • Kidneys, ureter, and bladder imaging often reveals gas distribution over the region of the kidneys (see Images 1-2). In patients with emphysematous pyelitis, the collecting system may be filled with gas. An ileus pattern may be seen, suggesting retroperitoneal inflammation.
  • Renal sonograms often reveal high echogenic areas with dirty shadowing. Hydronephrosis and perinephric fluid may also be seen (see Image 3).
  • CT scanning is the definitive test. Several patterns have been described, including streaky, streaky and mottled, and streaky and bubbly. Gas can be rimlike or crescent-shaped in the perinephric area. Gas can also be seen in the renal vein or inferior vena cava (see Images 4-6). Gas can be seen along the psoas muscle. Perinephric abscess may also lead to significant gas accumulation in the perinephric space. A stone may be seen in the collecting system.
  • Radiological classification
    • In 1970, Langston and Pfister described 3 main radiographic patterns, as follows:13
      • Diffuse mottling of the renal parenchyma
      • Bubbly renal parenchyma surrounded by crescent-shaped gas in the perinephric space
      • Extension of gas through the Gerota fascia
    • In 1984, Michaeli et al suggested 3 stages of EPN, as follows:14
      • Stage I - Gas within the renal parenchyma or the perinephric tissue
      • Stage II - Presence of gas in the kidney and its surroundings
      • Stage III - Extension of gas through Gerota fascia or bilateral EPN
    • In 1996, Wan et al described 2 distinct types of EPN, as follows:15
      • Type I - Characterized by parenchymal destruction with streaky or mottled parenchymal gas with an absence of fluid collection, which has a fulminant course and high risk of mortality
      • Type II - Characterized by renal or perirenal fluid collection with bubbly gas collection in the perinephric space or in the collecting system and a mortality rate of 18% (According to Wan et al, the compromised immune state of the host leads to fulminant and dry-type EPN, which is fatal.)
    • In 2000, Huang et al modified the staging proposed by Michaeli et al, as follows:1
      • Class 1 - Gas confined to the collecting system
      • Class 2 - Gas confined to the renal parenchyma alone
      • Class 3A - Perinephric extension of gas or abscess
      • Class 3B - Extension of gas beyond the Gerota fascia
      • Class 4 - Bilateral EPN or EPN in solitary kidney
    • Note that the classifications are not comparable.

Staging

See Imaging Studies.

More on Emphysematous Pyelonephritis

Overview: Emphysematous Pyelonephritis
Workup: Emphysematous Pyelonephritis
Treatment: Emphysematous Pyelonephritis
Follow-up: Emphysematous Pyelonephritis
Multimedia: Emphysematous Pyelonephritis
References
Further Reading
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References

  1. Huang JJ, Tseng CC. Emphysematous pyelonephritis: clinicoradiological classification, management, prognosis, and pathogenesis. Arch Intern Med. Mar 27 2000;160(6):797-805. [Medline].

  2. Tang HJ, Li CM, Yen MY, Chen YS, Wann SR, Lin HH, et al. Clinical characteristics of emphysematous pyelonephritis. J Microbiol Immunol Infect. Jun 2001;34(2):125-30. [Medline].

  3. Wan YL, Lo SK, Bullard MJ, Chang PL, Lee TY. Predictors of outcome in emphysematous pyelonephritis. J Urol. Feb 1998;159(2):369-73. [Medline].

  4. Shokeir AA, El-Azab M, Mohsen T, El-Diasty T. Emphysematous pyelonephritis: a 15-year experience with 20 cases. Urology. Mar 1997;49(3):343-6. [Medline].

  5. Pontin AR, Barnes RD, Joffe J, Kahn D. Emphysematous pyelonephritis in diabetic patients. Br J Urol. Jan 1995;75(1):71-4. [Medline].

  6. Kelly HA, MacCullum WG. Pneumaturia. JAMA. 1898;31:375-81.

  7. Cheng YT, Wang HP, Hsieh HH. Emphysematous pyelonephritis in a renal allograft: successful treatment with percutaneous drainage and nephrostomy. Clin Transplant. Oct 2001;15(5):364-7. [Medline].

  8. Schainuck LI, Fouty R, Cutler RE. Emphysematous pyelonephritis. A new case and review of previous observations. Am J Med. Jan 1968;44(1):134-9. [Medline].

  9. Huang JJ, Chen KW, Ruaan MK. Mixed acid fermentation of glucose as a mechanism of emphysematous urinary tract infection. J Urol. Jul 1991;146(1):148-51. [Medline].

  10. Yang WH, Shen NC. Gas-forming infection of the urinary tract: an investigation of fermentation as a mechanism. J Urol. May 1990;143(5):960-4. [Medline].

  11. Wang YC, Wang JM, Chow YC, Chiu AW, Yang S. Pneumomediastinum and subcutaneous emphysema as the manifestation of emphysematous pyelonephritis. Int J Urol. Oct 2004;11(10):909-11. [Medline].

  12. Gaither K, Ardite A, Mason TC. Pregnancy complicated by emphysematous pyonephrosis. J Natl Med Assoc. Oct 2005;97(10):1411-3. [Medline].

  13. Langston CS, Pfister RC. Renal emphysema. A case report and review of the literature. Am J Roentgenol Radium Ther Nucl Med. Dec 1970;110(4):778-86. [Medline].

  14. Michaeli J, Mogle P, Perlberg S, Heiman S, Caine M. Emphysematous pyelonephritis. J Urol. Feb 1984;131(2):203-8. [Medline].

  15. Wan YL, Lee TY, Bullard MJ, Tsai CC. Acute gas-producing bacterial renal infection: correlation between imaging findings and clinical outcome. Radiology. Feb 1996;198(2):433-8. [Medline].

  16. Chen MT, Huang CN, Chou YH, Huang CH, Chiang CP, Liu GC. Percutaneous drainage in the treatment of emphysematous pyelonephritis: 10-year experience. J Urol. May 1997;157(5):1569-73. [Medline].

  17. Aswathaman K, Gopalakrishnan G, Gnanaraj L, Chacko NK, Kekre NS, Devasia A. Emphysematous Pyelonephritis: Outcome of Conservative Management. Urology. Mar 25 2008;[Medline].

  18. Ahlering TE, Boyd SD, Hamilton CL, Bragin SD, Chandrasoma PT, Lieskovsky G, et al. Emphysematous pyelonephritis: a 5-year experience with 13 patients. J Urol. Dec 1985;134(6):1086-8. [Medline].

  19. Ahmad M. Emphysematous pyelonephritis due to Aspergillus fumigatus: a case report. J Nephrol. May-Jun 2004;17(3):446-8. [Medline].

  20. George J, Chakravarthy S, John GT, Jacob CK. Bilateral emphysematous pyelonephritis responding to nonsurgical management. Am J Nephrol. 1995;15(2):172-4. [Medline].

  21. Guvel S, Kilinc F, Kayaselcuk F, Tuncer I, Ozkardes H. Emphysematous pyelonephritis and renal amoebiasis in a patient with diabetes mellitus. Int J Urol. Jul 2003;10(7):404-6. [Medline].

  22. Roy C, Pfleger DD, Tuchmann CM, Lang HH, Saussine CC, Jacqmin D. Emphysematous pyelitis: findings in five patients. Radiology. Mar 2001;218(3):647-50. [Medline].

  23. Wheeler LD. Cystitis emphysematosa: case report. J Urol. Jan 1954;71(1):43-8. [Medline].

  24. Wu VC, Fang CC, Li WY, Hsueh PR, Chu TS. Candida tropicalis-associated bilateral renal papillary necrosis and emphysematous pyelonephritis. Clin Nephrol. Dec 2004;62(6):473-5. [Medline].

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Further Reading

For additional information, visit Medscape’s Diabetic Microvascular Complications Resource Center and Stone Disease Resource Center.

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Keywords

emphysematous pyelonephritis, emphysematous pyelitis, gas-forming infection of the urinary tract, EPN, renal parenchyma infection, urinary tract infection, UTI, pneumaturia, renal emphysema, pneumo-nephritis, pneumonephritis, diabetes, xanthogranulomatous pyelonephritis

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Contributor Information and Disclosures

Author

Sugandh Shetty, MD, Consulting Staff, Department of Urology, William Beaumont Hospital
Sugandh Shetty, MD is a member of the following medical societies: American Urological Association
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Ajay K Singh, MB, MRCP, MBA, Associate Professor of Medicine, Director of Dialysis, Department of Medicine, Harvard Medical School; Clinical Chief of Renal Division, Brigham and Women's Hospital
Disclosure: Nothing to disclose.

CME Editor

J Stuart Wolf, Jr, MD, FACS, David A Bloom Professor of Urology, Director, Division of Minimally Invasive Urology, Department of Urology, University of Michigan Medical Center
J Stuart Wolf, Jr, MD, FACS is a member of the following medical societies: American College of Surgeons, American Medical Association, American Urological Association, Catholic Medical Association, Endourological Society, Society for Urology and Engineering, Society of Laparoendoscopic Surgeons, and Society of University Urologists
Disclosure: Terumo Corporation Consulting fee Consulting; Omeros Corporation Consulting fee Consulting

Chief Editor

Edward David Kim, MD, FACS, Professor of Surgery, Division of Urology, University of Tennessee Graduate School of Medicine; Consulting Staff, University of Tennessee Medical Center
Edward David Kim, MD, FACS is a member of the following medical societies: American College of Surgeons, American Society for Reproductive Medicine, American Society of Andrology, American Urological Association, and Tennessee Medical Association
Disclosure: Lilly Consulting fee Consulting

 
 
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