ANEMIA: CAUSES, SYMPTOMS AND TREATMENT

WHAT IS ANEMIA?

Anaemia refers to a low red blood cell count and hematocrit level or haemoglobin level of less than 11.5gdl in women and 13.5gdl in men. This implies a reduction in the oxygen carrying capacity of the blood. This occurs as a result of fewer circulating erythrocytes than is normal or a decrease in the concentration of haemoglobin in circulating erythrocytes.  Physiologically, anaemia implies insufficient amounts of haemoglobin to deliver oxygen to the tissues.

INCIDENCE

The incidence of anaemia is extremely high. This is particularly evidenced in the under developed countries where nutrition is poor and the tropical regions where hookworm and malaria are endemic. Women of reproductive age especially, pregnant women and children are the most vulnerable. Anaemia is also prevalent in older people and it is the most common haematological condition that affects the elderly people.

AETIOLOGY 

The causes of anaemia in both children and adults can be put in the following main groups. It could be due to:

1. Excessive blood loss (haemorrhage)
2. Inadequate production of haemoglobin or red blood cells by the bone marrow (hypoplasia or aplasia)
3. Morphological abnormalities (shape, size and structure) of red blood cells
4. Excessive destruction of erythrocytes (haemolysis)
5. Disease condition e.g. Malaria, cancer, hypersplenism, hookworm infestation etc.
6. Deficiency of nutrients required for synthesis of red cells including iron, folic acid and protein.
7. Chemicals or drugs (cytotoxic drugs) with the potential to suppress bone marrow activity.

PATHOPHYSIOLOGY OF ANAEMIA 

The pathophysiology varies depending on the type and cause.  Despite the numerous causes and types of anaemia, it can be classified broadly into three aetiological categories which are: several blood vessels due to trauma, spontaneous rupture of an aneurysm, excessive or prolonged menstruation, bleeding in peptic ulcers, intestinal polyps, gastrointestinal bleeding etc; all the above lead to loss of large numbers of erythrocytes.  The sizes of the red blood cells are normal but few in numbers.  This means that the haemoglobin which is a constituent of the red blood volume is also reduced.  The blood volume is also reduced compared to pre-haemorrhagic blood volume.  Resulting from the reduction in haemoglobin, the oxygen carrying capacity of the blood will be low resulting in tissues hypoxia and its associate signs and symptoms.  If the iron stores are normal, the erythrocytes that were lost will be replaced by erythropoiesis but if iron stores are less or lacking, complications can be developed by the patient.  The severity of the type of anaemia depends on the rate of bleeding, the site of bleeding, the vessel involved and the volume of blood lost.In haemolytic anaemia, the red blood cells have defective haemoglobin due to hereditary or acquired disorders.  The disorders make the erythrocyte vulnerable to early destruction instead of the normal 120 days.  An imbalance between the red cell count and destruction occurs, hence, leading to a reduction in the number of the red blood cells in the circulatory blood.  Fewer red blood cells results in decrease oxygen deliver to the tissues causing fatigue, secondary to hypoxia.  The erythropoietin in turn stimulates the bone marrow to produce more erythrocytes to compensate for those destroyed.  As a result of haste production of the erythrocytes, most of them are released prematurely causing recticulocytosis which worsens the condition.  Further breakdown of the haemoglobin into heme and globin results in about 70-80% of the heme bring converted to bilirubin giving signs like bilirubineamia, bilirubinuria, jaundice, pruritis, visual disturbance etc.The hypoproliferative anaemia, there is decreased erythropoesis which may result from deficiency of factors essential for normal red blood cell production or by depressed bone marrow activity.  It may also occur into secondary disorders like renal diseases.  The essential factors which include, iron, vitamin B’12, folic acid, protein and vitamin B lacking or inadequate or any of them is absent can lead to reduction or abnormal formation of red blood cells.  If any of the above occurs, there will be fewer red blood cells in circulation leading to less oxygen for cellular and tissue metabolism.  Irrespective of the aetiological category of anaemia, the heart in an attempt to compensate beats faster than normal to supply oxygen and nutrients to the cells and tissues.  This brings about tachycardia, tachypnoea, palpitation etc; which redispose to heart failure.

TYPES OF ANAEMIA 

The different types of anaemia can be classified according to either aetiology or morphology of the red blood cells.  Aetiological  classification is related to clinical conditions causing anaemia such as decreased erythrocytes production, blood loss in haemorrhage, nutritional deficiencies e.g. vitamin B ’12, iron etc. or increased erythrocyte destruction.  Morphological classification is based on descriptive and objective laboratory information about erythrocyte size, shape and colour.  The types of anaemia based on aetiological classification include:

1. HAEMOLYTIC ANAEMIA 

This occurs when red cells are excessively destroyed while in circulation as may be seen in malaria. Thus, in this type of anaemia excessive haemolysis (disintegration of red cells) exceeds the erythropoietic ability of the red blood cells in the bone marrow. This type of anaemia is characterized by bilirubineamia and hemoglobinuria. The following are sub types of haemolytic anaemia;

• Sickle Cell Anaemia: This is a congenital haemolytic condition which occurs as a result of a defective haemoglobin molecule that causes red blood cells to roughen and become sickle shaped. It’s characterized by hyperbilirubinemia, hepatosplenomegaly and hyperplasia of the red bone marrow.

• Auto-immune Anaemia: It is an acquired disorder characterized by premature erythrocyte destruction from abnormalities in the individual own immune system.  The body produces antibodies which attack the red blood cells.  This more common in new born babies with A, O, B and rhesus incompatibilities.
• Thalassaemia Anaemia: This type occurs in two forms, major and minor. Both forms have the common feature of genetically determined defect in the cellular synthesis of the globin fraction of the haemoglobin.
• Glucose -6- Phosphate Dehydrogenase Deficiency (G6pd): This an inherited disease that causes haemolysis red blood cells when under stressed and in certain situations and as fever or the presence of certain drugs e.g. antimalarial drugs, sulfonamides, chloramphenicol, nitrofuration, the thiazide diuretics, common coal tar analgesics (aspirin), para-aminosalicylic acid (PAS), vitamin K etc. 

    2.  NUTRITIONAL ANAEMIA 

•  Iron Deficiency Anaemia: This is a type of anaemia in which iron level are lowered and therefore, does not meet the requirement or demand for formation of red blood cells. This is the most prevalent of the anaemia’s and mostly affects women of age 15-46 years who form the child bearing age and in young children. Iron deficiency results from:
•  Inadequate dietary intake of iron e.g. eggs, meat, green vegetables etc.
• Iron malabsorption due to chronic diarrhoea or partial or total gastrectomy.
• Blood loss due to heavy menses, haemorrhage from trauma or chronic loss of blood in hookworm infestation.

    3. APLASTIC ANAEMIA 

This is a type that comes about as result of depressed bone marrow activity. It involves failure to produce adequate red bone blood cells, white blood cells and platelets (pancytopenia) and hypo cellular bone marrow. A plastic anaemia could be congenital or acquired through radiation therapy, non-steroidal anti-inflammatory drugs (NSAIDs) e.g. Aspirin.

 4. HAEMORRHAGIC ANEMIA 

This is due to excessive blood loss which could be: 

1. Acute (large volume over a short period of time) due to injury. This type of bleeding can lead to shock.
2. Chronic (small volume long period of time) such as gastrointestinal bleeding.
3. Nature (as in menstruation in women) 

GENERAL CLINICAL FEATURES OF ANAEMIA 

Clinical manifestations associated with anaemia as stated in medical literature related to the body systems includes:

1. Skin: Pallor, brittle nails, koilonychia (spoon shaped fingernails), cheilosis (lesions at corners of the mouth) and pale mucous membrane.
2. Gastrointestinal system: Sore tongue (glossitis), anorexia, nausea, vomiting, indigestion and epigastric discomfort, pica.
3. Respiratory system: Dyspnoea on exertion increased respiratory rate.
4. Cardiovascular system: increased pulse rate, palpitations, cardiac enlargement, angina pectoris in severe anaemia, congestive heart failure.
5. Musculoskeletal Skeletal System: easily fatigues, muscle weakness, joint pain.
6. Nervous system: headaches, dizziness, tinnitus, tingling sensation and numbness (paraesthesia).
7. Reproductive system: impotence in men, amenorrhoea in women.

MEDICAL TREATMENT OF ANAEMIA 

The treatment of anaemia is directed towards treating the underlying cause of anaemia and restoring haemoglobin level to normal, replenishing iron stores after correction of anaemia in iron deficiency and restoring haemoglobin level to a stead state level in sickle cell patients.With the above treatment objectives, the following are given:

• Blood transfusion if the anaemia is severe.
• Iron preparations like ferrous sulphate orally:

Adults – 200mg three times daily.

Children – syrup (BPC), 600mg/5.0m

Up to 1 year – 5mls three times daily.

1-4 years – 10mls three times daily.

5-7 years – 15mls three times daily.

8-10 years – tab 200mg daily.

More than 10 years – tab 200mg twice daily

I.V saccharated iron oxide (fenivenin) 20-40 mg or I.M. iron sorbotol compound (jectofer) 100m

 

• Give anti-malarial drugs if anaemia is caused by malaria.
• In the case of sickle cell anaemia, hydroxyurea which is effective in haemoglobin level can be given. 
• Iron tablets are also given if there is evidence of iron deficiency. However, folic acid is given. The dosage of folic acid depends on the condition but it can also be administered prophylactically. Folic acid dosage is as follows:

Adults – 5mg daily x 30 days 

Children – 2.5-5mg daily x 30 days.

• Albendazole if anaemia is due to hookworm infestation. 400mg bid 3days for adults and children above 2 years, 200mg daily 3 days for children above 2 years.
• Injection of vitamin B’12Tab vitamin C
• Immunosuppressive therapy can be given which prevents lymphocytes from destroying the stem cells.
• Analgesics can be given to relief pain in the chest.
• Bed rest and high protein diet including green vegetables are necessary in the treatment of anaemia.

COMPLICATIONS OF ANEMIA

Anaemia result into the following complications: 

1. Infection 
2. Heart failure
3. Paraesthesia
4. confusion
5. Angina pectoris
6. Heart murmurs 
7. Brain death
8. Myocardial infarction 
9. shock