Anaemia is defined as a state in which the blood hemoglobin level or red cell count is below the normal range for the patients age sex and altitude of reference.
Haemoglobin levels vary with age, sex amd altitude.
Age & Sex -Normal refrence ranges are given below.
Hb level below the lower limit of refrence range is considerd as anemia.
Newborns: 17-22 gm/dl
One week of age: 15-20 gm/dl
One month of age: 11-15gm/dl
Children: 11-13 gm/dl
Adult male- 13 to 16 g/dl.
Adult female- 11.5 to 15 g/dl.
Altitude-People living at high altitudes have more haemoglobin because at high altitudes oxygen tension is less therefore to compensate for less oxygen their body responds by stimulation of more haemoglobin production via increased erythopoietin production.
CAUSES OF ANEMIA
(A) Blood loss:-which may be acute or chronic.
Acute blood loss- Loss of large quantity of blood within short span of time viz. trauma, Postpartum haemorrhage etc
Chronic blood loss:- Lpss of small volume of blood over prolonged period of time viz. Hookworm infection, menorrhagia , polymenorrhoea, bleeding peptic ulcer, hemorrhoids.
(B) Due to inadequate production of red cells or Haemoglobin.
a. Deficiency:- iron, vitamin B12, Folic acid.
b. Toxic factors like chronic inflammatory and infective diseases, hepatic failure, renal failure, drugs leading to aplastic anaemia.
c.Endocrine causes: hypothyroidism or hyperthyroidism, reduced EPO due to renal failure.
d.Marrow invasion:-leukaemia, fibrosis, secondary carcinomas etc
(C} Due to Excess destruction of red blood cells
- Genetic causes
a. Red cell membrane defects like spherocytosis, eleptocytosis etc
b. Haemoglobin defects like SCA and thalessemias.
c. Enzyme abnormalities like G-6 PD deficiency
- Aquared causes
Mechanical and infectious causes, immune, toxic.
- Easy fatigability, Lassitude & Dizzimess.
- Headache, syncope.
- Tinnitus, Vertigo.
- Irritability, sleep disturbance. Lack of concentration.
- Paraesthesia of fingers and toes.
- Polymenorrhea or oligoamenorrhoea.
- Symptoms of cardiac failure.
- Pallor of Skin, palette, nail beds, mucous membrane, palpebral conjunctiva.
- Tachycardia, wide pulse pressure,
- Cervical venous Hum, hyperdynamic precordium, ejection systolic murmur.
SIGNS SUGGESTING SPECIFIC ETIOLOGIES.
Fe deficiency--Angular stomatitis, glossitis, brittle finger nails, pica.
Jaundice-hemolytic anaemia chronic hepatitis, megaloblastic anaemia.
Splenomegaly, skeltal abnormalities- hemolytic anaemia.
Neurological changes- vitamin B12 deficiency.
Blood transfusion:- it is usually not indicated in all the patients with anemia.It is required in symptomatic and severely anemic patients.
Care has to be taken tl avoid circulatory overload especially in elderly and patients with cardiac compromise.
Hyperbaric oxygen:- May be required in severly anemic patients where blood cannot be immediately transfused due to religious or medical reasons like incomatability.
Deworming:- It is required in children to prevent nutritional deficiency anemia.
Supplementation:- Iron and folic acid and vit B12 supplements. Iron and folic acid tablets are especially given to pregnant females as they are at more risk of development of anemia because of haemodilution and increased demand during pregnancy.
Route of iron administration may vary from oral to intramuscular to intravenous depending on various factors.
[ K George Methews preap manual of medicine ]