Anaemia


Anaemia is defined as a haemoglobin (Hb) level below reference values, which vary depending on sex, age and pregnancy status (see Table 2).

Anaemia may be caused by:
− Decreased production of red blood cells: iron deficiency, nutritional deficiencies (folic acid, vitamin B12, vitamin A), depressed bone marrow function, certain infections (HIV, visceral leishmaniasis), renal failure;
− Loss of red blood cells: acute or chronic haemorrhage (ancylostomiasis, schistosomiasis, etc.);
− Increased destruction of red blood cells (haemolysis): parasitic (malaria), bacterial and viral (HIV) infections; haemoglobinopathies (sickle cell disease, thalassaemia); intolerance to certain drugs (primaquine, dapsone, co-trimoxazole, etc.) in patients with G6PD deficiency.

In tropical settings, the causes of anaemia are often interlinked.

Clinical features

– Common signs: pallor of the conjunctivae, mucous membranes, palms of hands and soles of feet; fatigue, dizziness, dyspnoea, tachycardia, heart murmur.
– Signs that anaemia may be immediately life threatening: sweating, thirst, cold extremities, oedema in the lower limbs, respiratory distress, angina, shock.
– Significant signs: chellosis and glossitis (nutritional deficiency), jaundice, hepatosplenomegaly, dark coloured urine (haemolysis), bleeding (maelena, haematuria, etc.), signs of malaria.

Laboratory

– Hb levels
– Rapid test or systematic thick and thin blood films in areas where malaria is endemic.
– Urinary dipstick: check for haemoglobinuria or haematuria.
– Emmel test if sickle cell disease is suspected.
– Blood cell count if available to guide diagnosis.

Table 1 - Possible diagnoses with blood cell count

Characteristics

Possible diagnoses

Macrocytic 

Deficiency (folic acid, vitamin B12), chronic alcoholism

Microcytic

Iron deficiency (malnutrition, chronic haemorrhage), chronic inflammation (HIV infection, cancer), thalassaemia

Normocytic 

Acute haemorrhage, renal failure, haemolysis

Reduced number of reticulocytes

Deficiency (iron, folic acid, vitamin B12), spinal tumour, renal failure

Increased or normal number of reticulocytes

Haemolysis, sickle cell disease, thalassaemia

Eosinophilia

Ancylostomiasis, trichuriasis, schistosomiasis, HIV infection, malignant haemopathies

Aetiological treatment

Anaemia in itself is not an indication for transfusion. Most anaemias are well tolerated and can be corrected with simple aetiological treatment.
Aetiological treatment may be given alone or together with transfusion.

– Iron deficiency
elemental iron PO for 3 months. Doses are expressed in elemental iron1 :
Neonate: 1 to 2 mg/kg 2 times daily
Child 1 month to < 6 years: 1.5 to 3 mg/kg 2 times daily
Child 6 to < 12 years: 65 mg 2 times daily
Child ≥ 12 years and adult: 65 mg 2 to 3 times daily


Age


Weight

Treatment
45 mg/5 ml syrup 65 mg tablet
< 1 month < 4 kg 0.5 ml x 2
1 month to < 1 year 4 to < 10 kg 1.5 ml x 2
1 to < 6 years 10 to < 20 kg 2.5 ml x 2
6 to < 12 years 20 to < 40 kg 1 tab x 2
≥ 12 years and adult ≥ 40 kg 1 tab x 2 or 3

or preferably,
elemental iron + folic acid  PO based on elemental iron dosages.

– Helminthic infections: see Schistosomiasis and Nematode infections (Chapter 6).

– Folic acid deficiency (rarely isolated)
folic acid PO for 4 months
Children < 1 year: 0.5 mg/kg once daily
Children ≥ 1 year and adults: 5 mg once daily

– Malaria: see Malaria (Chapter 6). In the event of associated iron deficiency, wait 4 weeks after malaria treatment before prescribing iron supplements.

– Suspected haemolytic anaemia: stop any drug that causes haemolysis in patients with (or that may possibly have) G6PD deficiency.

Blood transfusion

Indications

To decide whether to transfuse, several parameters should be taken into account:
– Clinical tolerance of anaemia
– Underlying conditions (cardiovascular disease, infection, etc.)
– Rate at which anaemia develops.
– Hb levels
If transfusion is indicated, it should be carried out without delay2 . For transfusion thresholds, see Table 2.

Volume to be transfused

In the absence of hypovolaemia or shock:
Children < 20 kg: 15 ml/kg of red cell concentrate in 3 hours or 20 ml/kg of whole blood in 4 hours
Children ≥ 20 kg and adults: start with an adult unit of whole blood or red cell concentrate; do not exceed a transfusion rate of 5 ml/kg/hour
Repeat if necessary, depending on clinical condition.

Monitoring

Monitor the patient’s condition and vital signs (heart rate, blood pressure, respiratory rate, temperature):
– During the transfusion: 5 minutes after the start of transfusion, then every 15 minutes during the first hour, then every 30 minutes until the end of the transfusion.
– After the transfusion: 4 to 6 hours after the end of the transfusion.

If signs of circulatory overload appear:
– Stop temporarily the transfusion.
– Sit the patient in an upright position.
– Administer oxygen.
– Administer furosemide by slow IV:
Children: 0.5 to 1 mg/kg
Adults: 20 to 40 mg
Repeat the injection (same dose) after 2 hours if necessary.
Once the patient has been stabilised, start the transfusion again after 30 minutes.

Prevention

– Iron (and folic acid) deficiency:
• Drug supplements
elemental iron PO as long as the risk of deficiency persists (e.g. pregnancy, malnutrition) 
Neonate: 4.5 mg once daily
Child 1 month to < 12 years: 1 to 2 mg/kg once daily (max. 65 mg daily)
Child ≥ 12 years and adult: 65 mg once daily


Age


Weight

Prevention
45 mg/5 ml syrup 65 mg tablet
< 1 month < 4 kg 0.5 ml
1 month to < 1 year 4 to < 10 kg 1 ml
1 to < 6 years 10 to < 20 kg 2.5 ml
6 to < 12 years 20 to < 40 kg 5 ml
≥ 12 years and adult ≥ 40 kg 1 tab

or preferably,
elemental iron + folic acid PO based on elemental iron dosages.

• Nutritional supplements (if the basic diet is insufficient)

– In the event of sickle cell anaemia: see Sickle cell disease (Chapter 12).

– Early treatment of malaria, helminthic infections, etc.



Table 2
 - Definition of anaemia and transfusion thresholds

Patient

Hb levels defining anaemia

Transfusion threshold

Children 2-6 months

< 9.5 g/dl

Hb < 4 g/dl, even if there are no signs of decompensation

Hb ≥ 4 g/dl and < 6 g/dl if there are signs of decompensation or sickle cell disease or severe malaria or serious bacterial infection or pre-existing heart disease

Children 6 months-5 years

< 11 g/dl

Children 6-11 years

< 11.5 g/dl

Children 12-14 years

< 12 g/dl

Men

< 12 g/dl

Hb < 7 g/dl if there are signs of decompensation or sickle cell disease or severe malaria or serious bacterial infection or pre-existing heart disease

Women

< 13 g/dl

Pregnant women

< 11 g/dl
(1st and 3rd trimester)

< 10.5 g/dl
(2nd trimester)

< 36 weeks

Hb ≤ 5 g/dl, even if there are no signs of decompensation

Hb > 5 g/dl and < 7 g/dl if there are signs of decompensation or sickle cell disease or severe malaria or serious bacterial infection or pre-existing heart disease

≥ 36 weeks

Hb ≤ 6 g/dl, even if there are no signs of decompensation

Hb > 6 g/dl and < 8 g/dl if there are signs of decompensation or sickle cell disease or severe malaria or serious bacterial infection or pre-existing heart disease


Footnotes
Ref Notes
1 Available in 140 mg/5 ml syrup of ferrous fumarate containing approximately 45 mg/5 ml of elemental iron and 200 mg ferrous sulfate tablets or ferrous sulfate + folic acid tablets containing 65 mg of elemental iron. Tablets of 185 or 200 mg ferrous fumurate or sulfate + folic acid (60 or 65 mg of elemental iron) contain 400 micrograms folic acid.
2 Before transfusing: determine the recipient’s and potential donors’ blood groups/rhesus and carry out screening tests on the donor’s blood for HIV-1 and 2, syphilis and, in endemic areas, malaria and Chagas disease.