Difference between revisions of "Hemolytic uremic syndrome"

(Management)
(Text replacement - "Nifedipine " to "Nifedipine")
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*Insulin therapy if hyperglycemic and ketones (pancreatic insufficiency complication)
 
*Insulin therapy if hyperglycemic and ketones (pancreatic insufficiency complication)
 
*Anti-hypertensives
 
*Anti-hypertensives
**Nifedipine ER (0.25-0.5 mg/kg/day oral)
+
**[[Nifedipine]]ER (0.25-0.5 mg/kg/day oral)
 
**Labetolol 1-3 mg/kg/day, divided into twice daily dosing (12 mg/kg/day up to 1200 mg/day)
 
**Labetolol 1-3 mg/kg/day, divided into twice daily dosing (12 mg/kg/day up to 1200 mg/day)
 
**Nitroprusside 0.3-0.5 ug/kg/min IV (max 10 ug/kg/min)
 
**Nitroprusside 0.3-0.5 ug/kg/min IV (max 10 ug/kg/min)

Revision as of 16:34, 14 August 2018

Background

  • Abbreviation: HUS
  • Similar to TTP (which is more common in adults), but associated with less central nervous system and more renal involvement.
  • Most cases occur in children <10yr (⅔ of cases in < 5yr)
  • 80-90% cases due to E. coli O157:H7 infection
  • Shiga toxin may induce autoantibody to CD36 (found on endothelial cells and platelets)
  • May also be caused by shigella, yersinia, campylobacter, salmonella

Types

  1. Typical
    • Occurs 2-14d after development of infectious diarrhea (bloody, no fever)
  2. Atypical
    • Occurs in older children and adults
    • Extrarenal involvement is common (difficult to distinguish from TTP)
    • May be caused by atypical pathogens (EBV, S. pneumo) or immunosuppression

Clinical Features

Triad

  1. Acute renal failure
  2. Thrombocytopenia
  3. Microangiopathic Hemolytic Anemia (MAHA)

Other Associated Conditions

  • Enteritis
  • Nausea/vomiting, diarrhea (usually bloody), +/- fever
  • Hyperglycemia
  • Pancreatic beta-cell death due to microthrombi within pancreas

Differential Diagnosis

Causes of Glomerulonephritis

Microangiopathic Hemolytic Anemia (MAHA)

Thrombocytopenia

Decreased production

Increased platelet destruction or use

Drug Induced

Comparison by Etiology

ITP TTP HUS HIT DIC
↓ PLT Yes Yes Yes Yes Yes
↑PT/INR No No No +/- Yes
MAHA No Yes Yes No Yes
↓ Fibrinogen No No No No Yes
Ok to give PLT Yes No No No Yes

Evaluation

  • CBC
    • Anemia
    • Thrombocytopenia
    • Peripheral smear checking for schistocytes, burr cells, helmet cells, spherocytes and segmented red blood cells
  • LDH (elevated)
  • Haptoglobin (decreased)
  • Reticulocyte count (appropriate)
  • PT/PTT/INR (normal; differentiates from DIC)
  • Stool tests
    • Shiga toxin, E. coli O157:H7 test
  • Urinalysis
    • Hematuria, casts
  • LFT
    • Increased bilirubin
  • Chemistry
    • Creatinine, hyperkalemia (renal failure)

Management

  • Fluid resuscitation
  • Insulin therapy if hyperglycemic and ketones (pancreatic insufficiency complication)
  • Anti-hypertensives
    • NifedipineER (0.25-0.5 mg/kg/day oral)
    • Labetolol 1-3 mg/kg/day, divided into twice daily dosing (12 mg/kg/day up to 1200 mg/day)
    • Nitroprusside 0.3-0.5 ug/kg/min IV (max 10 ug/kg/min)
  • Plasma exchange (plasmapheresis)
    • Usually performed if anuria or neurologic sequela
  • Eculizumab
    • Monoclonal anti-C5 antibody that interrupts complement cascade
  • Transfusion of RBCs(only severe bleeding)
    • Generally only indicated if plasma exchange cannot be performed immediately
  • Platelet Transfusion is AVOIDED
    • Only used for life-threatening bleeding or intracranial hemorrhage under guidance from hematologist
    • Platelet infusion may lead to acutely worsened thrombosis, renal failure, and death
  • Hemodialysis/Hemoperfusion
    • Often needed for renal failure and hyperkalemia treatment
  • AVOID Antibiotics
    • May lead to worsening lysis of bacteria and further shiga toxin release
  • AVOID Antimotility agents
    • Leads to prolonged gut exposure to toxins
    • Risk of toxic megacolon

Disposition

  • Admit

See Also

References

  • Corrigan J. Boineau FG. Hemolytic-uremic syndrome. Pediatr Rev. Nov 2001;22(11):365-9
  • George J. Clinical practice. Thrombotic thrombocytopenic purpura. N Engl J Med 2006; 354:1927