Anemia, overview

Notes
  • It is defined as a decrease in the total amount of red blood cells (RBCs) or hemoglobin in the blood
  • Statistics: Normal values of HB in men -13 to 14 g/dL; Normal values of HB in women - 12 to 13 g/dL; 25% of global population is anemic; anemia is the most common disorder of the blood; the global mortality due to iron deficiency anemia in 2013 was 183,000

##The three main categories of causes of anemia are:

  • Blood loss e.g. trauma, menorrhagia, fibroids, helminthiasis, over-sampling in anemia of prematurity and GIT bleeding
  • Inadequate production of RBC e.g. iron deficiency, a lack of vitamin B12, thalassemia, and a number of neoplasms of the bone marrow.
  • Excessive destruction of RBC e.g. sickle cell anemia, malaria and other infections, and some autoimmune diseases.

##Anemia is also classified based on the size of RBC and amount of hemoglobin in each cell as:

  • Microcytic anemia (small size RBC) - due to hemoglobin synthesis insufficiency e.g. Iron deficiency anemia, Anemia of chronic disease, sideroblastic anemia, and alpha or beta-thalassemia
  • Macrocytic anemia (large size RBC) - due to a deficiency of either vitamin B12, folic acid, or both
  • Normocytic anemia (normal size RBC) – it occurs when the overall hemoglobin levels are decreased, but the red blood cell size remains normal e.g. acute blood loss, aplastic anemia, and hemolytic anemia
Symptoms
  • It may be asymptomatic
  • Fatigue
  • Irritability
  • Paleness of the skin, tongue, lips, conjunctiva and nail beds
  • Jaundice (yellowing of the skin and eyes)
  • Koilonychia (in iron deficiency) - spoon nails
  • Apnea
  • Dizziness
  • Poor ability to exercise
  • Pica (tendency to eat stone chips, ice, paper, wax, grass etc.)
  • Changed stool color
  • Confusion
  • Loss of consciousness
  • Intermittent claudication of the legs
  • Thirst
  • Hypotension
  • Palpitations
  • Tachycardia
  • Splenomegaly
  • In severe anemia, there can be fainting, shock, chest pain, angina and heart attack
  • A short, soft, apical, “haemic” systolic murmur
Diagnosis
  • Complete Blood Count including RBC count, hemoglobin concentration, MCV and RDW that facilitate calculations of hematocrit, MCH, and MCHC
  • Thin blood film examination for cell morphology and blood parasites
  • Urinalysis
  • Stool for ova of helminths and occult blood
  • Bone marrow
  • Sickling test/HB Electrophoresis
  • Flow cytometry (to measure the size of RBCs)
Differential
  • Low LDL Cholesterol (Hypobetalipoproteinemia)
Prevention
  • Prophylactic administration of iron and folic acid (such as in pregnancy)
Management

##Treatment of underlying causes

  • Malaria treatment (refer to “Malaria” in this book or package for details) followed by prophylactic dose if spleen is palpable
  • For mild to moderate anemia, give the following for at least 3 months after the normal HB has been attained: Tabs Ferrous Sulphate 200mg TID and Tabs Folic acid 5mg OD
  • For patients who cannot be transfused with blood (e.g. those with chronic renal failure or when the blood is not available) administer parenteral iron.
  • Treat hookworm infestation.
  • For sickle cell anemia, give antimalarials and folic acid for prophylaxis

## Blood transfusion – criteria:

  • If HB ≤ 6 g/dL or when the patient displays early features of hemodynamic instability OR
  • If HB ≤ 8 g/dL but the patient has lost ≥ 20% of the blood or there is hypotension or cold extremity or active bleeding with shock or slow capillary refill.

##Others

  • Erythropoiesis-stimulating agent
  • Hyperbaric oxygen (for those who cannot be transfused)
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