Question

What are anticoagulants? What are the practical applications of anticoagulants, such as heparin, in Medicine?

Answer 1

Anticoagulants are the chemical which prevent clotting of blood when mixed with blood in proper proportion.
There are different types of anticoagilants are:-

Ethylenediamine tetra-acetic acid (EDTA)
EDTA remove calcium from blood which is essential for the coagulation called as chelating agent. It also inhibits fibrinogen to fibrin. It is used in a concentration of 1 - 2 mg of the unhydrous salt per ml of blood. It preserves cellular elements more than 3 hours, therefore it is widly used for determination of haemoglobin concentration, WBCs count, RBCs count, PCV, ESR and platelets count.

Double oxalate
It is a mixture of 3 parts of ammonium oxalate and 2 parts of potassium oxalate. It is used in concentration of 2 mg for the 1 ml of blood. Oxalates acts by removing calcium ions from the plasma as in the insoluble oxalate. It is used for determination of Haemoglobin %, ESR estimation, RBCs count and leucocytes count.

Trisodium citrate
It converts the ionised calcium into non-ionised form. It is used in a concentration of 2 - 3 mg for 1 ml of blood, it is used to perform coagulation test, blood transfusion and ESR estimation.

Heparine
This anticoagilants is used when plasma is required urgently for certain emergency estimation of blood gases and electrolytes. It inhibit present thrombin . It is used in concentration of 1 - 2 mg per ml of blood.

Acid citrate dextrose (ACD)
Sodium citrate - 1.32 gm.
Citric acid - 0.48 gm.
Dextrose - 1.40 gm.
Distilled water- 100 ml.
Above mixture is used the 4 ml blood for 1 ml ACD mixture. It precipitate the calcium ions. It is used in the Blood Bank for collecting blood for transfussion. It is also used for enzyme study, red cells preservation and for hemolytic process. It is not suitable for Haemoglobin % and blood cells count because it is used as liquid that dilute the cellular elements.

Sodium fluride
Sodium fluride is an inhibitor. It is used for determination of blood sugar. It preserve blood for 24 hours at room temprature and 4 to 6 day in refrigerator.