Anaemia is defined as a low haemoglobin level (adult males <13 g/dl; adult females <12 g/dl; pregnant women, <11 g/dl). The common causes of anaemia in India are:
Reduced production due to deficiency of iron, folic acid, or vitamin B12; or an ineffective erythropoiesis secondary to many causes (anaemia of chronic disease, secondary to infections and inflammation, endocrinal disorders, primary bone marrow disorders like infiltration or hypoplasia). Blood loss (which also leads to iron deficiency).
Increased destruction of RBCs (haemolysis due to many causes of which, a thalassaemia is the commonest).
Tiredness, weakness and lack of desire to work, light headedness and headache. Nails and tongue look pale. Severe anaemia produces general pallor. Many aetiologies may be determined on the basis of MCV performed in an accurate cell counter :
– Low MCV—iron deficiency or haemoglobinopathy like thalassaemia.
– High MCV—folic acid or B12 deficiency. Less commonly alcohol intake, liver disease, haemolysis and hypothyroidism.
– Normal MCV—anaemia of chronic disease, primary bone marrow disorders, renal failure, haemolysis.
In case of associated leucocyte and platelet abnormalities or if anaemia does not respond to therapy in 4 weeks despite correcting the apparent cause, a bone marrow examination by aspiration/biopsy should be performed.
Consider admission if possible in malignancy or infiltrative disorder; Hb <6 g/dl (including iron deficiency); hemolysis. Transfusion where possible should be deferred until a definitive diagnosis is made.
Iron deficiency anaemia
1. Treat the underlying cause: Menorrhagia in women, gastrointestinal blood loss in all age groups including hookworm infestation, dietary deficiency, rarely malabsorption.
2. Tab. Ferrous sulfate 200 mg 3 times a day. Reduce the dose as haemoglobin rises to over 10 g/dl. Once haemoglobin is normal, continue with 1 tablet daily for at least three months. Other preparations of iron are not superior, but they can be tried if patient does not find ferrous sulfate suitable. These include ferrous fumarate and ferrous gluconate.
The rate of rise of haemoglobin should be 1 g/dl per week. If this does not occur, consider ongoing blood loss, noncompliance, and associated haemoglobinopathy like thalassaemia carrier status, malabsorption, or an incorrect diagnosis. Parenteral iron does not lead to a faster rise in haemoglobin. It is indicated in the following situations:
(i) Intolerance of oral iron, (ii) In late pregnancy to ensure that foetal stores of iron are replenished rapidly, (iii) If ongoing blood loss exceeds the capacity to absorb oral iron (like in inoperable malignancy), (iv) In noncompliant patient, (v) Malabsorption of iron. (Caution: There is danger of anaphylactoid reactions; hence facilities to manage these should be readily available).
Folic acid deficiency
1. Treat the cause: Dietary deficiency, increased requirement as in pregnancy and children, haemolytic anaemia.
2. Tab. Folic acid 5 mg daily. This dose is adequate even in malabsorption syndrome.
Vitamin B12 deficiency
1. Treat the cause: Dietary deficiency in vegetarians and pernicious anaemia. Although uncommon, it is also under diagnosed due to lack of facilities.
2. Tab. Vitamin B12 500 mcg thrice in a day until recovery, then 500-1000 mcg once in a day as in haematinic tablets.
Inj. Vitamin B12 1000 mcg IM, one injection on alternate days for total 5 injections, then once a week for 5 weeks, then once in 3 to 6 months will be adequate for most patients.
Note: Oral vitamin B12 is indicated only in dietary deficiency states, and not in pernicious anaemia. Patient education
Educate the patient about preventive measures for worm infestation. Inform about importance of taking adequate food with green leafy vegetables to meet the nutritional requirement and cooking food in iron utensils may increase iron content in the diet.
Iron tablets sometimes produce stomach upset, therefore, take iron tablets after meals; reduce the dose of iron, if it produces stomach ache, diarrhoea or constipation.
Iron should not be taken with milk or milk products; should be either taken one hour before or two hours after milk or milk products. Stools would turn black during oral iron therapy.
Explain that the response to iron therapy is gradual and it takes weeks or months for haemoglobin to become normal. Continue iron tablets for 6 months. Keep iron tablets out of the reach of children. They may swallow the tablets as candies causing adverse reactions including death.