Comparison of hydroxyethyl starch with plasma and dextrans in severe haemodilution

Abstract

A long-term comparison of hydroxyethyl starch with the commonly used blood substitutes, dextran 75, dextran 40, and buffered, homologous plasma was performed, using a haemodilution technique which clinically simulates the correction of haemorrhage. All animals receiving dextran 75, and three of four animals receiving either dextran 40 or hydroxyethyl starch survived for at least eight days. Only one animal that received buffered plasma survived more than 24 hours. Possible causes of death were discussed. The mechanisms of adaptation to the acute reduction of arterial oxygen content were similar in all groups. Whereas the mean cardiac index and coefficient of oxygen extraction rose, mean arterial blood pressure, oxygen consumption, and venous oxygen saturation declined moderately. Since no evidence of anaerobic metabolism was observed, apparently oxygen delivery to tissues was well maintained. One week following haemodilution most parameters had returned to normal values, although haemoglobin content remained less than 50 per cent of control. Hydroxyethyl starch was as adequate a colloidal substitute as dextran 40 and dextran 75 in its ability to sustain circulatory and metabolic parameters. © 1968 Canadian Anesthesiologists.