[Comparison of hydroxyethyl starch solutions derived from potato and corn starch]

The study was designed to investigate the effects of hydroxyethyl starch (HES) solutions derived from potato (p) compared to HES derived from corn (c) starch on the colloidosmotic pressure, plasma viscosity, and to measure the plasma and urine concentration.

After approval by the Ethics Committee, and having obtained informed consent, we recruited 20 patients undergoing lumbar disc surgery who received either 1000 ml of p-HES or c-HES (MW 200,000 DS 0.5) in a randomized, single-blind way. Colloidosmotic pressure, plasma viscosity and the plasma concentration were measured before and 30, 90, 240 min and one day after the infusion. Statistical analysis was performed using chi-square and Mann-Whitney test. There were no differences between the two groups in regard to demographics and anesthesia.

Plasma viscosity and colloidosmotic pressure did not change significantly during that time. There were no differences in plasma concentration and excretion of both solutions. The peak plasma concentration was reached after 30 min in both groups (8.57 +/- 3.92 g/l c-group and 7.67 +/- 4.68 g/l p-group) and declined thereafter. Within 6 h 38% (c-group 23.0 +/- 3.2 g HES) and 28% (p-group 16.8 +/- 1.6 g HES) of the infused HES were found in the urine. 12 h later about 50% was excreted.

The present study demonstrated that there was no clinically apparent effect on hematorheology and pharmacokinetics between these two solutions.