Modern rapidly degradable hydroxyethyl starches: current concepts.

Hydroxyethyl starch (HES) is a widely used plasma substitute for correcting perioperative hypovolemia. HES preparations are defined by concentration, molar substitution (MS), mean molecular weight (M(w)), the C(2)/C(6) ratio of substitution, the solvent, and the origin. The possible unwanted side effects of HES are anaphylactic reactions, alterations of hemostasis resulting in increased bleeding, kidney dysfunction, accumulation, and pruritus. In view of the potential side effects, it is crucial to distinguish among the different HES preparations; all HES preparations are not the same. The first generation of HES preparation showing a high M(w) (>450 kD) and a high MS (>0.7) was associated with negative effects with regard to coagulation, organ function, and accumulation. This review is focused on whether modern (third generation), more rapidly degradable HES preparations with a lower M(w) (130 kD) and a lower MS (<0.5) are safer and have fewer side effects. Several studies demonstrated that such modern HES preparations appear to be safe with regard to hemostasis, kidney function, itching, and accumulation. Modern HES preparations are dissolved in balanced, plasma-adapted solutions that no longer contain unphysiological amounts of sodium and chloride and are thus suitable for correcting hypovolemia.