Anemia: Difference between revisions
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==Diagnosis== | ==Diagnosis== | ||
''Assess for any signs of bleeding or trauma before considering other causes of bleeding'' | |||
[[File:Anemia.png|thumb|Algorithm for the Evaluation of Anemia]] | [[File:Anemia.png|thumb|Algorithm for the Evaluation of Anemia]] | ||
===Microcytic Anemia (<81 fL)=== | ===Microcytic Anemia (<81 fL)=== | ||
Revision as of 03:03, 16 August 2015
Background
- Affects 1/3 of the world's population
- Most common causes are uterine and GI bleeding
- Pathophysiology
- 4 mechanisms:
- Loss of RBCs by hemorrhage (e.g. GI bleed)
- Increased destruction (SCD, hemolytic anemia)
- Impaired production (iron/folate/B12 deficiency, aplastic/myelodysplastic anemia)
- Dilutional (rapid IVF infusion)
- 4 mechanisms:
Clinical Features
General Anemia Symptoms
- Most patients begin to be symptomatic at ~7gm/dL
- Weakness, fatigue, lethargy, dyspnea on exertion, palpitations
- Skin, nail bed, mucosal pallor
- Widened pulse pressure
- Jaundice, hepatosplenomegaly (hemolysis)
- Peripheral neuropathy (B12 deficiency)
Differential Diagnosis
Anemia
RBC Loss
RBC consumption (Destruction/hemolytic)
- Hereditary
- Acquired
- Microangiopathic Hemolytic Anemia (MAHA)
- Autoimmune hemolytic anemia
Impaired Production (Hypochromic/microcytic)
- Iron deficiency
- Anemia of chronic disease
- Thalassemia
- Sideroblastic anemia
Aplastic/myelodysplastic (normocytic)
Megaloblastic (macrocytic)
- Vitamin B12/folate deficiency
- Drugs (chemo)
- HIV
Diagnosis
Assess for any signs of bleeding or trauma before considering other causes of bleeding
Microcytic Anemia (<81 fL)
- RDW high
- Ferritin low: Iron deficiency anemia
- Ferritin normal: Anemia chronic disease or sideroblastic anemia (e.g. lead poisoning)
- RDW normal
- RBC count low: Anemia chronic disease, hypothyroidism, Vitamin C deficiency
- RBC count nl or high: Thalassemia
Normocytic Anemia (81-100 fL)
- Retic count normal
- RDW normal: Anemia chronic disease, anemia of renal insufficiency
- RDW high: Iron, Vit B12, or folate deficiency
- Retic count high
- Coombs Positive: Autoimmune cause
- Coombs negative: G6PD, SCD, spherocytosis, microangiopathic hemolysis
Macrocytic Anemia (MCV>100 fL)
- RDW high: Vit B12 or folate deficiency
- RDW normal: ETOH abuse, liver disease, hypothyroidism, drug induced, myelodysplasia
Treatment
- Transfusions
- Consider if pt is symptomatic, hemodynamically unstable, hypoxic, or acidotic
- Most pts w/ Hb <6 will benefit from transfusion; most pts w/ Hb >10 will not
- Always draw labs necessary for diagnosis prior to transfusing
- 1 unit PRBCs should raise the Hgb by 1gm/dL