Topic: Anemia Faculty: Medicine Course: BSc ATOT - 2nd year - Anemia: definition, classification - Iron deficiency anemia - Megaloblastic anemia

1. Anemia
Dr. Salman Ahmad Ansari
Kanachur Institute of Medical Sciences

2. Anemia
Definition: reduction in the number of circulating RBCs

3. Classification
Based on
Underlying process
Morphology of RBC

4. Based on underlying cause:
- Decreased RBC production:
- Iron, vit. B12 or folate deficiency
- Aplastic anemia
- Bone marrow suppression
- Increased RBC destruction:
- Hemolytic anemias like sickle cell disease, hereditary
spherocytosis
- Blood loss:
- Acute or chronic blood loss

5. Based on morphology of RBC:
- Microcytic anemia(MCV<80 fL)
- Macrocytic anemia(MCV>100 fL)
- Normocytic anemia(MCV between 80-100 fL)

7. - Microcytic anemia:
- Iron deficiency anemia
- Anemia of chronic disease
- Thalassemia
- Macrocytic anemia:
- Vit. B12 and folate deficiency
- Acute leukemia
- Alcohol abuse
- Normocytic anemia:
- Acute blood loss

8. Iron deficiency anemia
- It is the commonest cause of microcytic anemia

9. Causes of iron deficiency
Decreased iron intake or absorption
• Inadequate diet
• Malabsorption (celiac sprue, postgastrectomy)
Increased demand for iron
• Rapid growth in infancy or adolescence
• Pregnancy
Increased iron loss
• Acute blood loss (blood donation, trauma)
• Chronic blood loss (peptic ulcer, GI malignancy, hookworm infestation, menses)

10. Clinical features
Symptoms
● Fatigue
● Exertional dyspnea
● Palpitations
● Headache
● Amenorrhea or menorrhagia, excess hair loss
● Pica: eating nonfood items
● Pagophagia: eating ice

11. Signs:
● Glossitis and angular stomatitis
● Bald tongue: smooth and pale
● Flat nails: platynychia
● Concave nails: koilonychia

12. Angular stomatitis

13. Bald tongue

16. Investigations
Complete blood count(CBC):
- RBC count
- Hemoglobin
- Hematocrit
- MCV, MHC, MCHC
Peripheral smear: shows microcytic hypochromic RBCs
Serum iron: decreased
Total iron binding capacity(TIBC): increased
Transferrin saturation, serum ferritin: decreased
Other tests: stool for occult blood, upper GI scopy
ALL DECREASED

18. Treatment
● Replacement of iron and correction of iron deficiency
● Iron can be given either orally or parenterally
● Treatment of cause of iron deficiency: e.g: hookworm
infestation

19. Oral iron therapy
- Safer and cheaper than parenteral
- Single dose of iron at bedtime
- Ferrous fumarate, ferrous sulfate, ferrous gluconate
- Avoid taking with milk, antibiotics, tea, coffee
- 6-8 weeks of iron therapy for Hb levels to normalise
- But treatment is continued for a total of 6 months to replenish iron
stores
- Adverse effects can be reduced by gradually increasing the dose
and giving it after meals

20. Parenteral iron therapy
- For those who cannot tolerate oral therapy and in pregnant women
who present late
- Iron dextran, ferric gluconate and iron sucrose: i.m or i.v
- Given after test dose
- i.m given by Z track technique to prevent staining of skin
- Side effects:
- Pain, muscle necrosis, phlebitis
- Anaphylactic reactions
- Fever, urticaria, join pain

21. Megaloblastic anemia

22. Megaloblastic anemia
RBCs with MCV more than 100 fL (femtoliters) are called
macrocytes (megaloblasts).
Causes of macrocytic anemia:
● Vit B12 deficiency
● Folic acid deficiency
● Drugs: 6-mercaptopurine, azathioprine, acyclovir, zidovudine

24. Causes of vit. B12 deficiency:
- Decreased intake: strict vegetarians
- Intrinsic Factor deficiency: pernicious anemia, gastrectomy
- Decreased absorption: malabsorption syndromes, fish
tapeworm infestation
- Agents that block absorption: metformin, PPIs(omeprazole)

25. Clinical features
● Easy fatiguability, dyspnea, effort intolerance
● Palpitations, headache
● Atrophic glossitis
● Peripheral neuropathy: paresthesia, ataxia, loss of vibration
and position sense
● Severe deficiency: subacute combined degeneration of
spinal cord(SCD)
● Memory loss, dementia

26. Investigations
Complete blood count:
- Hb: low
- MCV: >100 fL
- MCH, MCHC: normal
Peripheral blood smear: macrocytes, hypersegmented neutrophils
Bone marrow: hypercellular, iron stores are normal, megaloblasts
seen

28. Vit. B12 and folic acid levels: decreased
Other tests:
- Schilling test: to diagnose the cause of Vit. B12 deficiency
- Upper GI scopy

29. Treatment
Severe anemia(<7 g/dl): packed RBC transfusion
Vit. B12 replacement:
- Parenteral route
- 1000 microgram i.m weekly for 4 weeks followed by 1000
microgram monthly lifelong
- Oral therapy is usually not effective if malabsorption is the
cause
- Treat the underlying cause of vit. B12 deficiency. E.g:
deworming for tapeworm infestation

30. References:
● Manipal Prep Manual of Medicine
Questions:
salman.s.ansari92@gmail.com
For PPT, scan: