Safety of hypertonic hyperoncotic solutions--a survey from Austria

Hypertonic hyperoncotic solutions (HHS), composed of 7.2 to 7.5% sodium chloride and 6 to 10% dextran or hydroxyethyl starch, are able to restore the disturbed macro- and microcirculation in hypovolemic states within a short period of time. Even small amounts of HHS induce a relevant fluid shift from the extravasal into the intravasal space, and the use of HHS has thus been recommended in acute hypovolemia and hypovolemic shock (principle of "small-volume resuscitation"). Recently, attention has also focused on the treatment of elevated intracranial pressure using HHS. Austria is the only European country where market authorization of HHS was already obtained several years ago and where HHS have been widely used in clinical routine for a comparatively long time. This offers the unique possibility of evaluating, for the first time, the safety profile of HHS solutions. In this study, we analyzed the reported adverse drug reactions of HHS in a large number of applications.

Marketing and pharmacovigilance data as well as other relevant information obtained in Austria during the years 1991 to 2000, were used for analysis of safety aspects of HHS applications in routine clinical practice.

From 1991 to 2000, four adverse drug reactions related to HHS were reported, none of which was fatal. Out of these, 3 have to be regarded as anaphylactoid/anaphylactic reactions to hydroxyethyl starch. In one case an extreme overdose was infused resulting in a hyperosmolar syndrome. In the same time period approximately 56,000 HHS units were used in Austria in about 18,500 to 37,000 patients. With these numbers, the frequency of adverse drug reactions related to the prescribed application of HHS can be calculated: approximately 5 adverse drug reactions per 100,000 HHS units used; approximately 8-16 adverse drug reactions per 100,000 HHS-treated patients.

Austrian experience with the use of a large number of HHS in clinical routine during nearly a decade indicates that the prescribed application of a combination of hydroxyethyl starch and hypertonic sodium chloride has a low potential for complications.