Гидроксиэтилкрахмал

Описание

Hydroxyethyl starch (HES) is a synthetic colloid that consists of hydroxyethylated polymers of glucose, derived from amylopectin. It is one of the most frequently used plasma substitutes. HES products are approved for the treatment of hypovolemia (low blood volume).

Химические свойства

White to light yellow powdery solid, non-toxic and odorless. It is easily soluble in water and insoluble in organic solvents. It has properties such as emulsification, dispersion, suspension, and adhesion, and can be used as an aid in filtration and retention of pulp materials. It can also reduce the chemical oxygen demand and biochemical oxygen demand of wastewater.

Использование

Hydroxyethyl starch, commonly known as Hespen, is a synthetic colloid volume expander, mainly used for first aid in patients with hemorrhagic shock, traumatic shock, and burn shock. Its characteristic is that it is not restricted by blood type. An intravenous solution of hydroxyethyl starch is used to prevent shock following severe blood loss caused by trauma, surgery, or other problems.

Подготовка

Hydroxyethyl starch is produced by the hydroxyethylation reaction of hydrolyzed starch with ethylene oxide and sodium hydroxide.

Общее описание

Hydroxyethyl starches (HES) are nonionic starch derivatives and were one of the most frequently used intravascular volume expanders.

Клиническое использование

Hydroxyethyl starch is often used as a plasma substitute for therapy of hypovolemia after trauma, burns, infections or during surgery.It is also widely used for hemodilution treatment of cerebral ischemia and of retinal, otogenic or peripheral perfusion disturbances.In treatment of cerebral ischemia, a hypervolemic therapy protocol has been shown to be more effective than an isovolemic infusion. Another indication is the hyperdynamic treatment of vasospasm in subarachnoid hemorrhage.Some of these indications require relatively high dosages to ensure efficacy of therapy.However, during continuous treatment with large volumes of HES, disturbances of coagulation and hemor- rhagic complications are not uncommon. Trumble et al. reported bleeding complications during hetastarch therapy of vasospasm in subarachnoid hemorrhage patients and recommended the use of plasma protein fraction instead.Van den Brink observed coagulopathy under therapy with highly sub- stituted medium molecular weight HES.These disturbances of the coagulation sys-tem were found to be due to an acquired von Willebrand syndrome.

Метаболизм

Ten volunteers were given 500 ml 6% HES solution by intravenous infusion, and serial blood and urine samples were collected for nonglucose total carbohydrate determination. On average, 46 and 64 percent of the dose was excreted in the urine within two and eight days. The plasma concentration declined rapidly during the first week after infusion. The average terminal half-life was 17 days during the first 42 days, which accounted for the elimination of about 90 percent of the dose. The remainder was eliminated with a terminal half-life of 48 days determined between days 42 and 83 of the study. The infusion of HES resulted in plasma volume expansion over a 48-hour when nonglucose carbohydrates were above 3.5 mg/ml. HES is metabolized by alpha-amylase in the body. During the first 48 hours after infusion of HES, plasma alpha-amylase activity was significantly increased over control. Concomitantly, alpha-amylase activity in urine was also elevated but not significantly so[1].