Anaemia

Content

• Anaemia

• Classification of anaemia

• Etiology of iron deficiency anaemia

• Pathogenesis of IDA

• Clinical features

Objective

At the end of this PDF Notes, students able to

• Explain different types of haematological diseases

• Explain the etiology of iron deficiency anaemia

• Elaborate the pathogenesis of iron deficiency anaemia and its treatment

Haematological diseases

BLOOD

• Components of Blood

Anemia

• Condition in which the oxygen-carrying capacity of blood is reduced

• Characterized by reduced numbers of RBCs or a decreased amount of hemoglobin in the blood

General manifestations of anemia

Reduced oxygen delivery can result in the following:

• Ischemia

• Fatigability

• Breathlessness upon exertion

• Exercise intolerance

• Pallor

• Increased susceptibility to infection

Classification of Anemia

1) Based on Size changes

2) Color changes (due to altered hemoglobin content)

• Normochromic — Normal hemoglobin concentration

• Hypochromic — Reduced hemoglobin concentration

Example: Iron deficiency anemia may be classified as a microcytic, hypochromic anemia as both red blood cell size and hemoglobin content are reduced

3) Blood loss anemia: Anemia that results from acute blood loss.

4) Iron-deficiency anemia: It can occur as a result of iron-deficient diets

5) Cobalamin-deficiency or folate-deficiency anemia

6) Inherited anemia- Sickle cell anaemia

Iron Deficiency Anemia

• The commonest nutritional deficiency disorder present throughout the world is iron deficiency

Absorption

• Haem iron is better in absorption than non haem iron

• Non-haem iron is released as ferrous or ferric form

• Transport across the membrane by divalent metal transporter 1 (DMT 1)

TRANSPORT:

• Iron is transported in plasma bound to a β-globulin, transferrin, synthesised in the liver

• Transferrin bound iron utilise for haemoglobin synthesis.

• Transferrin is reutilised after iron is released from it.

EXCRETION:

The body is unable to regulate its iron content by excretion alone. The amount of iron lost per day is 0.5-1 mg.

DISTRIBUTION. In an adult, iron is distributed in the body as under:

• 1. Haemoglobin—(65%).

• 2. Myoglobin—(3.5%).

• 3. Haem and non-haem enzymes—(0.5%).

• 4. Transferrin-bound iron—(0.5%)

• 5. Ferritin and haemosiderin—a (30%).

Iron absorption

Absorption of Iron

Pathogenesis of Iron deficiency anaemia

• Iron deficiency anaemia develops when the supply of iron is inadequate for the requirement of haemoglobin synthesis.

• The development of iron deficiency depends upon one or more of the following factors:

Etiology of Iron deficiency anaemia

I. INCREASED BLOOD LOSS

1. Uterine e.g. excessive menstruation in reproductive years, repeated miscarriages, at onset of menarche, post-menopausal

uterine bleeding

2. Gastrointestinal e.g. peptic ulcer, haemorrhoids, hookworm infestation, cancer of stomach and large bowel, oesophageal varices, hiatus hernia, chronic aspirin ingestion, ulcerative colitis, diverticulosis

3. Renal tract e.g. haematuria, haemoglobinuria

4. Nose e.g. repeated epistaxis

5. Lungs e.g. haemoptysis

II. INCREASED REQUIREMENTS

1. Spurts of growth in infancy, childhood and adolescence

2. Prematurity

3. Pregnancy and lactation

III. INADEQUATE DIETARY INTAKE

1. Poor economic status

2. Anorexia e.g. in pregnancy

3. Elderly individuals due to poor dentition, apathy and financial constraints

IV. DECREASED ABSORPTION

1. Partial or total gastrectomy

2. Achlorhydria

3. Intestinal malabsorption such as in coeliac disease

Clinical Features of Iron deficiency anaemia

• Iron deficiency anaemia is much more common in women between the age of 20 and 45 years than in men

• More frequent in premature infants.

Clinical consequences of iron deficiency:

1)anemia

2)epithelial tissue changes

Treatment of Iron deficiency anaemia

The management of iron deficiency anaemia consists of 2 essential principles:

1) Correction of disorder causing the anaemia: checkup and investigations.

2) 2)Correction of iron deficiency: i) Oral therapy

ii) Parenteral therapy

Summary

• Anaemia is the condition in which the oxygen-carrying capacity of blood is reduced