Haemopoietics are substances that help the bone marrow produce healthy blood cells. These include essential nutrients like iron, vitamin B12, and folic acid, as well as naturally occurring growth factors. Plasma expanders, on the other hand, are fluids used to increase blood volume in emergencies such as shock or severe blood loss. Understanding both groups is important because they support blood formation and circulation.
What Are Haemopoietics?
Haemopoietics support the production of red blood cells (RBCs), white blood cells (WBCs), and platelets. The bone marrow requires:
- Essential nutrients — Iron, vitamin B12, folic acid
- Growth factors — Erythropoietin, G-CSF, GM-CSF, IL-11
- Accessory factors — Trace elements like copper, cobalt, manganese
Deficiency of any essential component can lead to anaemia or poor blood cell formation.
Iron
Iron is crucial for forming haemoglobin, the oxygen-carrying protein in RBCs. Good sources include meat, fish, liver, spinach, dry fruits, and jaggery. An adult male typically has about 4 grams of iron stored in the body.
How Iron Is Absorbed
- Dietary iron is first converted to the ferrous form in the stomach.
- Most absorption occurs in the duodenum and upper jejunum.
- Absorption increases in iron deficiency.
- Vitamin C enhances iron absorption.
- Milk, antacids, and foods high in phytates reduce absorption.
Oral Iron Preparations
Commonly used oral iron salts include:
- Ferrous sulphate – inexpensive and effective
- Ferrous fumarate – higher elemental iron content
- Ferrous gluconate
- Other forms: iron choline citrate, ferric ammonium citrate, carbonyl iron
Side effects include nausea, vomiting, stomach pain, constipation or diarrhoea, and dark stools.
Parenteral Iron Preparations
Used when oral iron is not tolerated or absorbed:
- Iron dextran
- Iron sorbitol–citric acid complex
- Ferric carboxymaltose
- Ferrous sucrose
- Iron isomaltoside
- Ferumoxytol
Given either intravenously or intramuscularly. Risks include allergic reactions, skin staining, pain, headache, fever, and rarely circulatory collapse.
Uses of Iron
- Treatment of iron-deficiency anaemia
- During pregnancy to prevent anaemia
- Infants and children with nutritional deficiency
- Patients with chronic kidney disease taking erythropoietin
Iron Poisoning
Seen mostly in children who accidentally swallow excess tablets. Symptoms include vomiting, abdominal pain, bloody diarrhoea, metabolic acidosis, coma, and shock.
Antidote: Desferrioxamine is used to bind iron and promote its excretion.
Vitamin B12
Vitamin B12 is essential for DNA synthesis and normal maturation of red blood cells. Its deficiency causes megaloblastic anaemia and neurological problems.
Sources & Absorption
- Found in meat, eggs, fish, and dairy products.
- Absorbed in the ileum with intrinsic factor.
- Deficiency is common in strict vegetarians and older adults.
Uses
- Treatment of pernicious anaemia
- Megaloblastic anaemia due to B12 deficiency
- Neuropathy caused by deficiency
Folic Acid
Folic acid is needed for DNA synthesis and RBC production. Deficiency leads to megaloblastic anaemia, especially in pregnancy, alcoholism, and malnutrition.
Uses
- Treatment of folate-deficiency anaemia
- Prevention of neural tube defects during pregnancy
Plasma Expanders
Plasma expanders are fluids that increase blood volume when a patient loses a significant amount of blood or plasma. They help maintain circulation and stabilize blood pressure.
When Plasma Expanders Are Used
- Burns causing plasma loss
- Severe bleeding or shock
- Major trauma
- Surgery with heavy fluid loss
Common Plasma Expanders
- Dextran – increases blood volume but may cause allergic reactions
- Gelatin-based fluids – moderate effect, lower allergy risk
- Hydroxyethyl starch (HES) – effective but used cautiously
- Human albumin – highly effective but expensive
Precautions
Plasma expanders should be used carefully in patients with:
- Heart failure
- Kidney problems
- Bleeding disorders
Detailed Notes:
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