Dextran

Dextrans are macromolecules composed of glucose subunits. They are given intravenously (IV) and have a number of beneficial effects in health care. They were originally designed as volume expanders to treat hypovolemia or shock because they are both osmotically active, and too large to pass through the uninjured vessel wall.

Dextran has numerous pharmacologic effects when infused intravenously

• Anti-platelet activity

• Anti-fibrin activity

• Plasma volume expansion in hypovolemia

• Improves microcirculation by decreasing blood viscosity and impeding erythrocyte aggregation

Dextran 40 is usually given at a dose of 25 cc per hour for approximately 5 days post-operatively after microvascular transplantation.    In children, dextran 40 is usually run at 8-10 cc/kg/24hrs. 

Microsurgeons use dextran because they bind to platelets, red blood cells, and the lining of the vessel wall decreasing their ability to stick together and ultimately form clots. When the endothelium or inside lining of a blood vessel is injured, elements normally covered become exposed. This activates circulating platelets which adhere to the vessel wall and each other starting a cascade which results in occlusion or clotting of the vessel lumen. Endothelium will heal and return to a "non-stick" state after about 5 days. Dextran is used to protect vessel patency for this period of time.

Complications are rare with dextran use.