Effects of a hydroxyethylstarch solution on plasma colloid osmotic pressure in acutely ill patients

Hydroxyethyl starch (HES) solutions can represent an alternative to human albumin solutions in intensive care unit (ICU) patients, but their effects on the plasma colloid osmotic pressure (COP) have not been well defined. We studied the changes in COP in 61 critically ill patients; 39 patients received 500 ml HES 6% (Elo-Haes Fresenius solution) and 22 received 400 ml of a human albumin solution (4% albumin Belgian Red Cross) over 60 to 90 min. COP was determined with an oncometer, using a semi-permeable membrane at 30 Kd, before the infusion, at the end of the infusion, and one hour and four hours after the end of the infusion. COP increased in the HES group from 20.7 +/- 3.1 to 22.5 +/- 3.1 mmHg (p < 0.05), and this increase in COP was sustained throughout the 4 hours of the study. COP did not increase in the human albumin group (from 19.5 +/- 2.4 to 19.9 +/- 2.0 mmHg, NS). Hence, this standard HES solution has greater effects on COP than natural colloids. In view of their lower costs, HES solutions can represent a valuable alternative to human albumin. However, it is necessary to consider the secondary effects of HES and the physiologic functions of albumin.