[Changes in physicochemical parameters and coagulation factors in hemodilution with dextran of molecular weight 60,000].

In 18 subjects undergoing aorto-bifemoral by-pass, pre-operative isovalaemic hemodilution was carried out (using a dextran of molecular weight 60,000) at the same time as venous section of a mean value of 1087 ml reducing the hematocrit to 0.30. The following were studied before, immediately after and 24 hours after hemodilution: blood viscosity (at variable shearing rates), oncotic pressure, sedimentation rate, clotting factors, plasma electrolytes. These results showed that at the end of hemodilution, oncotic pressure was maintained and even increased despite the fall in blood protein levels, with also a decrease in blood viscosity, a tendency to dynamic hypocoagulability (thrombocytopenia, fall in fibrinogen and increase in cephalin kaolin time and Quinck time) without any increase in lytic activity. 24 hours later, these parameters tended to return to normal. Discussion on the basis of a study carried out in vitro, seeks to demonstrate which of these changes were related to the dextran molecule and which were related to the hemodilution.