[Rheological and expander effect of hydroxyethyl-starch in intradural anesthesia]

We have evaluated the effect of the infusion of hydroxyethylstarch (HES) on blood viscosity and its usefulness to prevent hypotension associated with intradural anesthetic blockade. The sample consisted of 20 healthy patients scheduled for elective surgery with intradural anesthesia (0.5% hyperbaric bupivacaine), in whom 500 ml of HES were infused in 20 minutes. Blood samples were taken before lumbar puncture and 20 minutes after it and once HES infusion had been finished. Blood viscosity, the erythrocyte and leukocyte mass parameters and biochemical values (total protein, BUN, creatinine, glucose) were measured. Blood pressure (systolic, diastolic, mean) and heart rate were monitored every 5 minutes. During the study time, systolic blood pressure did not show significant changes. Mean and diastolic blood pressure in the minutes 15 and 20 were reduced in less than 10 mmHg (p less than 0.01). Packed red cell volume diminished in 5.7% and the blood viscosity in 0.5-2.3 mPas. It was concluded that HES is a good option for intradural anesthesia because of its plasma volume expanding effect and the hemodilution it induces.