Hetastarch

2.1.3 Hetastarch
Hetastarch is a semisynthetic material that essentially comprises of more than 90% amylopectin, which has been treated with pyridine and ethylene chlorohydrin, so as to give rise to 7 to 8 hydroxyethyl substituents present for every 10 D-glucopyranose units of the starch polymer. The molecular weight is approximately 450, 000 daltons.
Amylose Derivative

Where R or R′ = H or CH2-CH2-OH
Amylopectine Derivative It specifically differs from the amylose derivative in that the sequenceis frequently interrupted by a unit in which R is the residue of an additional o-hydroxyethylated α-D-glucopyranosyl moiety that essentially constitutes the first unit in a branch or sub-branch of the polymer.
Uses
1. It serves as a ‘Plasma Volume Expander’. A 6% solution is osmotically equivalent to a 5% albumin solution. But in the blood, it draws up certain quantum of water either from the intestinal or intracellular fluids, thus expanding the blood volume slightly in excess of the volume infused.This acquired expansion lasts for 24 to 36 hours.
2. It is employed in the management and treatment of hypovolemic shock*.
3. It is also used as a suspension medium for leukapheresis**.
4. It is employed as a cryoprotective*** agent for erythrocytes.
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* Shock caused due to diminished blood volume.
** The separation of leukocytes from blood, which are then transfused back into the patient.
*** A chemical that protects cells from the effect of cold.

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