Dextrans are a type of colloids and are used for intravenous transfusion. The Dextran Injection is aavailable as Dextran 70 (mol. wt. 70,000 Daltons), Dextran 150 (mol. wt. 1,50,000 Daltons) and Dextran 40 (mol. wt. 40,000 Daltons). Dextrans are polysaccharides. These solutions can be stored for 10 years. Half life of dextrans is 2 to 8 hours.
The dextran injection is indicated in cases of severe intravascular volume depletion, where loading with crystalloids will not be sufficient. Their infusion increases the intravascular significantly particularly in cases of acute severe blood loss or in hypovilemic shock. The use of Dextrans is common in intensive care units.
Advantages of using Dextran
- Dextrans are non toxic, neutral and chemically inert . Hence, the incidence of allergies is less when Dextran Injection is given.
- Low molecular weight dextran (Dextran 40) improves microcirculation, so it is more useful in conditions where microcirculation is compromised.
Drawbacks of using Dextran
- Dextran Injection interferes with blood grouping and cross matching (because they can cause red cell aggregation).
- Interferes with platelet function and can result in coagulation abnormalities.
- Can cause severe anaphylaxis.
- Large molecular weight dextrans can block renal tubules.
- Can cause ARDS (rarely) because of direct toxic effect on pulmonary capillaries.