Hemolytic anemia

Background

  • Wide variety of clinical presentation given the large differential diagnosis
  • Clinical presentation and lab findings differ depending on intravascular vs. extravascular hemolysis, acute vs. chronic
  • Common findings
    • low hemoglobin and hematocrit
    • reticulocytosis
    • elevated indirect bilirubin
  • Most important lab to elucidate diagnosis is blood smear
  • Most common emergent presentations are due to acute intravascular hemolytic anemias

Etiologies

Divided by etiology: acquired vs. hereditary

Clinical Features

History

PMH

Physical Exam

Differential Diagnosis

Acquired Hemolytic Anemia

Microangiopathic Hemolytic Anemia

Autoimmune

Infection

Other

Hereditary/Congenital Hemolytic Anemia

Evaluation

Workup

  • CBC
    • Low hemaglobin/hematocrit
    • Low platelet count → microangiopathic hemolytic anemia
  • Blood smear
  • Reticulocyte count
  • CMP
    • Most important: indirect bilirubin and creatinine
  • UA (for hemoglobin, hemosiderin), uHCG
  • PT/INR
  • Hemolysis labs
    • LDH
    • Haptoglobin
    • Fibrinogen
  • Direct Anti-Globulin Test or Coombs test
  • If concern for Malaria:
    • Thick and thin prep
    • Parasitemia
  • HIV
  • Blood cultures, urine cultures
  • Consider LP if neuro symptoms

Lab Interpretation

Microangiopathic Hemolytic Anemia H/H Platelets Indirect Bili Creatinine Blood Smear PT/INR LDH Haptoglobin Fibrinogen DAT/Coombs Test Thick/Thin Prep
HUS low low elevated highly elevated schistocytes wnl elevated low wnl negative negative
TTP low low elevated elevated schistocytes wnl elevated low wnl negative negative
DIC low low elevated elevated schistocytes elevated elevated low low negative negative
Malignant Hypertension low low elevated variable schistocytes elevated low negative negative
Autoimmune H/H Platelets Indirect Bili Creatinine Blood Smear PT/INR LDH Haptoglobin Fibrinogen DAT/Coombs Test Thick/Thin Prep
Warm Antibody AHA low wnl elevated spherocytes elevated low wnl positive negative
Infection H/H Platelets Indirect Bili Creatinine Blood Smear PT/INR LDH Haptoglobin Fibrinogen DAT/Coombs Test Thick/Thin Prep
Malaria low wnl elevated see thick/thin prep variable elevated low wnl negative paracytes
Babesia see thick/thin prep negative paracytes
Other H/H Platelets Indirect Bili Creatinine Blood Smear PT/INR LDH Haptoglobin Fibrinogen DAT/Coombs Test Thick/Thin Prep
Brown recluse low wnl elevated elevated positive negative

Management

  • ABC’s and resuscitation if necessary, 2 large bore IVs
  • Emergent hematology consultation if patient is very ill appearing

Acquired Hemolytic Anemia

Microangiopathic Hemolytic Anemia

  • HUS
    • Supportive Care
      • Hydration
      • Pain control
    • Hemodialysis if acute renal failure
    • Do NOT give antibiotics: results in increased expression of Shiga Toxin from E. Coli O157:H7
  • TTP
    • Avoid platelet transfusion, except in life-threatening bleeding or intracranial hemorrhage
    • Plasma exchange
    • If Plasma exchange cannot be performed immediately, give FFP and plasmapharese later.
    • Factor VIII concentrate
  • DIC
    • Platelet transfusion if count is <50,000 and/or significant bleeding
    • pRBC if active bleeding or hemodynamically unstable
    • FFP if active bleeding
    • Cryoprecipitate if fibrinogen <150 and bleeding
    • TXA is only indicated for active or massive bleeding
  • Malignant hypertension
    • Reduce blood pressure as clinically indicated

Autoimmune

  • Warm antibody autoimmune hemolytic anemia
    • High-dose corticosteroids PO (1-2mg/kg per day for 3-4 weeks)
    • Monoclonal antibodies and immunosuppressive agents
    • Plasma exchange for severe hemolysis
    • Allogeneic RBC transfusion for life-threatening anemia

Infection

Other

  • Brown recluse spider bite
    • Supportive care
      • Hemodynamic support with fluids and pressers if necessary
      • Blood product transfusion if necessary

Hereditary/Congenital Hemolytic Anemia

Disposition

  • Depends on severity, complications, etc.

See Also

External Links

References

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