Pharmacodynamics and tolerability of acetyl starch as a new plasma volume expander in patients undergoing elective surgery

Objective: Acetyl starch (ACS) is a new synthetic colloid solution for plas ma volume expansion and is now undergoing phase II clinical trials. We comp ared the pharmacodynamics and tolerability of ACS with those of hydroxyethy l starch (HES) in 32 patients (American Society of Anesthesiologists physic al status I and II) undergoing elective surgery. Subjects, material and met hods: In this prospective, randomized, double-blind trial patients received either 15 ml/kg ACS 6% (average molecular weight (Mw) 200,000/molar substi tution (MS) 0.5) or HES 6% (Mw 200,000/ MS 0.5) i.v. up to a maximum dose o f 1000 ml. Plemodynamic parameters, theologic parameters, volume effect, ac id-base status as well as effects on hemostasis were studied. Results: Afte r infusion of ACS and HES there was a similar increase in central venous pr essure and mean arterial pressure in both groups. Acid-base status was not significantly altered after the end of the colloid infusions. After ACS inf usion, plasma acetate concentration increased from 0.13 +/- 0.16 mg/dl to 2 .87 +/- 1.13 mg/dl, however, after 24 h there was no significant difference in plasma acetate concentration compared to HES. The volume effect ranged from 104 - 116% (ACS) and from 88 - 118% (HES) of the colloid dose administ ered. These differences were not statistically significant. Partial thrombo plastin time (aPTT) was only slightly increased after ACS infusion (from 38 .6 +/- 5.7 sec to 41.4 +/- 5.1 sec), but was significantly increased after HES infusion (from 38.7 +/- 5.7 sec to 46.1 +/- 7.0 sec). Conclusion: ACS a nd HES are equally effective plasma volume expanders; ACS might be a new, a lternative colloid solution with fewer coagulation side-effects than HES.