Hydroxyethyl starch--can the safety problems be ignored?

Hydroxyethyl starch (HES) has come into widespread use for fluid management of acutely ill patients. Certain characteristic complications of HES, notably renal impairment, hemorrhage and pruritus, have been well documented with all types of HES solutions. The use of HES solutions with lower molecular weight and substitution has been claimed to minimize these safety risks. In particular, solutions of 200 kDa molecular weight and 0.5 substitution (HES 200/0.5) and of 130 kDa molecular weight and 0.4 substitution (HES 130/0.4) have been advocated for their superior safety profile. A critical appraisal of the available evidence does not provide reassurance that these or other HES solutions are risk free. Most evidence indicates the equivalence of HES 200/0.5 and HES 130/0.4 with respect to effectiveness for volume expansion. Since HES 130/0.4 is newer, its safety profile is less well characterized; however, it appears to share the same complication risks as those of HES 200/0.5. In randomized clinical trials employing sensitive markers, both HES 200/0.5 and HES 130/0.4 have been shown to impair renal function. Both coagulopathy and clinical bleeding have been documented after administration of either HES 200/0.5 or HES 130/0.4, and the magnitude of negative effects on hemostasis has been similar for these two HES solutions. Pruritus is a common side effect of all HES solutions, including HES 200/0.5 and HES 130/0.4, and can occur in diverse clinical settings in some cases after only small HES doses. Typically presenting as pruritic crises of delayed onset, this complication is often severe, protracted and refractory to treatment. An additional risk of HES infusion is the occurrence of potentially life-threatening anaphylactoid reactions, which are 4.5 times as frequent after HES as albumin exposure. Limiting the dose and duration of HES therapy may be helpful in lessening the risk of undesired side effects; at present however, reliance on particular HES solutions does not appear sufficient to ensure safety.