Hemolytic uremic syndrome

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Hemolytic uremic syndrome, abbreviated HUS, is the triad of:[1]

Definition

  • Microangiopathic hemolytic anemia.
    • Microangiopathic = disease affecting small blood vessels.[2]
  • Thrombocytopenia = low platelet count.
  • Acute renal failure.

Memory device

HUS is the RAT in TTP:

  • Renal failure.
  • Anemia.
  • Thrombocytopenia.

RAT is a subset of the CRAFTY mnemonic for TTP:[3]

  • CNS symptoms.
  • Renal failure.
  • Anemia - microangiopathic hemolytic anemia.
  • Fever.
  • Thrombocytopenia.
  • Y - no one knows "Y" it occurs.

Etiology

  • Rare (uncooked) hamburger.
  • E. coli serotype O157:H7.
    • Verotoxins from E. coli O157:H7 --> endothelial injury.[4]

Pathology

General

  • In children, partial omentectomies are done during the placement of peritoneal catheters, to avoid subsequent (catheter) blockage.[5]

Microscopic

Features:

  • Mesothelial-lined fibroadipose tissue.

Relation to thrombotic thrombocytopenic purpura (TTP)

  • TTP is the main (clinical) DDx of HUS.
    • It is classically characterized by: microangiopathic hemolytic anemia, thrombocytopenia, fever, mild renal failure, and prominent neurologic symptoms.
  • Both are classified as thrombotic microangiopathies.[6]

See also

References

  1. URL: http://emedicine.medscape.com/article/779218-overview. Accessed on: 8 September 2010.
  2. URL: http://www.mercksource.com/pp/us/cns/cns_hl_dorlands_split.jsp?pg=/ppdocs/us/common/dorlands/dorland/one/000005089.htm. Accessed on: 9 September 2010.
  3. URL: http://www.valuemd.com/mnemonics2.php. Accessed on: 8 November 2010.
  4. Petruzziello TN, Mawji IA, Khan M, Marsden PA (February 2009). "Verotoxin biology: molecular events in vascular endothelial injury". Kidney Int. Suppl. (112): S17–9. doi:10.1038/ki.2008.612. PMID 19180125.
  5. Pumford N, Cassey J, Uttley WS (1994). "Omentectomy with peritoneal catheter placement in acute renal failure". Nephron 68 (3): 327–8. PMID 7838254.
  6. URL: http://emedicine.medscape.com/article/779218-overview. Accessed on: 8 September 2010.