Anemia

Anemia
3 major classes include:
i) marrow production defects (hypoproliferation)
- typically seen with a low reticulocyte production index together with little or no change in red cell morphology (a normocytic, normochromic anaemia)
- includes early iron deficiency (before hypochromic microcytic red cells develop), acute and chronic inflammation (including many malignancies), renal disease, hypometabolic states such as protein malnutrition and endocrine deficiencies, and anemias from marrow damage.
- most common anemias and anemia associated with acute and chronic inflammation is the most common

ii) Red cell maturation defects (ineffective erythropoiesis)
- typically have a slight to moderately elevated reticulocyte production index that is accompanied by either macrocytic (e.g. Megaloblastic anaemia) or microcytic (haemoglobinopathies) red cell indices.
- Megaloblastic anemias are disorders caused by impaired DNA synthesis. Cells primarily affected are those having relatively rapid turnover, especially hematopoietic precursors and gastrointestinal epithelial cells. Cell division is sluggish, but cytoplasmic development progresses normally, so megaloblastic cells tend to be large, with an increased ratio of RNA to DNA. Megaloblastic erythroid progenitors tend to be destroyed in the marrow. Thus, marrow cellularity is often increased but production of red blood cells (RBC) is decreased.
- Hemoglobinopathies are disorders affecting the structure, function, or production of hemoglobin. These disorders are usually inherited and range in severity from asymptomatic laboratory abnormalities to death in utero. Different forms may present as hemolytic anemia, erythrocytosis, cyanosis, or vasoocclusive stigmata.
iii) Decreased red cell survival (blood loss / hemolysis)
- Increased red blood cell destruction secondary to hemolysis results in an increase in the reticulocyte production index to at least three times normal, provided sufficient iron is available for hemoglobin synthesis. Hemorrhagic anemia does not typically result in production indices of more than 2.5 times normal because of the limitations placed on expansion of the erythroid marrow by iron availability.
- The loss of red cells either through hemorrhage or, less commonly, through premature destruction of the red cells (hemolysis) may cause anemia. Hemolysis or blood loss normally leads to an increase in red cell production, which is clinically manifested by an increase in reticulocytes.
Clinical Features:
Symptoms:
- fatigue, lasitude
- throbbing headache & earache, dizziness &
tinnitus
- faintness
- breathlessness, palpitations
- angina, parasthesia
- intermitent claudication
- dimness of vision, insomnia
Signs:
- Pallor, Tachycardia
- Cardiac failure, systolic flow murmurs
- Edema
- Mass (malignancies)
- Bone tenderness
- Papilloedema and retinal haemorrhage after an
acute bleed (usually accompanies with blindness)
Specific signs of different types of anaemias:
- koilonychia – spoon-shaped nails seen in iron
deficiency anaemia
- jaundice – found in haemolytic anaemia
- bone deformities – found in Thalassaemia major
- leg ulcers – occur in association with sickle cell
Disease
Investigations
Full blood count
a. Hb level
b. MCV
Haematinics Assay
Peripheral Smear
Bone Marrow

DEFINITION : a state in which the blood hemoglobin level is below the normal range for the patient's age, sex, altitude and residence.

Normal hemoglobin levels :
Males : 13 - 18 g/dl
Females : 12 - 16.0 g/dl
Pregnant female : more than 11 g/dl


CLASSIFICATION :
1)BASED ON AETIOLOGY

a)Due to blood loss
- ACUTE BLOOD LOSS: trauma, postpartum haemorrhage
-CHRONIC BLOOD LOSS : bleeding peptic ulcer, hook worm infestation, haemorroids, menorrhagia

b)Decreased RBC production
-Nutritional deficiency : iron, folate, vitamin B12
-Toxic factors : chronic inflammatory and infections (tuberculosis), liver failure
-Endocrine deficiency : hypothyroidism, hypopituitarism, hypoadrenalism, hypogonadism, reduced erythropoietin in renal failure
-Marrow invasion: leukaemia, fibrosis, secondary carcinoma
-Marrow failure : hypoplastic, anaplastic anaemia

c)Increased destruction
- Genetic disorders : Cell membrane disorders of RBC eg. hereditary spherocytosis, Enzyme defects eg G6PD deficiency, structural abnormality of haemoglobin thalassemia
- Acquired disorders : Immune disorder eg SLE, Drugs, infections

2)BASED ON RBC MORPHOLOGY

a)Normocytic anaemia : haemolytic anemia
b)Microcytic anaemia : iron deficiency anaemia, thalassemia, hereditary spherocytosis
c)Macrocytic anaemia : vitamin B12 and folate deficiency anaemia

CLINICAL FEATURES :

Symptoms : fatigue, liassitude, dyspnoea, palpitation, dizziness, headache, syncope, irritability, anorexia, nausea, symptoms of cardiac failure, amenorrhea or polymenorrhea

Signs : pallor of skin, palms, oral mucosa, nail beds, palpebral conjunctiva. tachycardia, oedema, cervical venous hum, hyperdynamic praecordium, ejection systolic murmur,

GENERAL MANAGEMENT :

-Investigations of cause of anaemia from detailed history
-Complete blood picture, peripheral smear, serum iron, folate
-occult blood in stool
-haemoglobin electrophoresis

Treatment :
-Blood transfusion in symptomatic and severely anaemic patients. PAcked cells preferred, with precautions to avoid circulatory overload
-Treatment of infections, cardiac failure and underlying cause of anaemia

For anemia, when you do not have enough red blood cells. This hampers the blood to carry oxygen, causing unusual tiredness and other symptoms.

Number of red blood cells can drop if there is:

* A reduction in the number of red blood cells produced

* Increased loss of red blood cells.