INCREASED HEMODILUTION IN HYPOTENSION INDUCED BY EPIDURAL-ANESTHESIA

This study examined whether the increased haemodilution from fluid loading in patients who develop hypotension at the onset of epidural anaesthesia (EDA) can be explained by high-level blockade or by stress-induced elevation of the blood glucose concentration. In 20 men aged between 53 and 87, crystalloid volume loading was carried out with 10 ml . kg-1 b.w. and EDA was induced with mepivacaine 2% and adrenaline 1:200 000. Irrespective of the blood pressure reaction to the blockade, there was no change in blood glucose level. A strong linear correlation between haemodilution and arterial pressure was found, in spite of unchanged blood glucose levels, in 10 patients in whom EDA was induced with bupivacaine 0.5%, and in 10 patients who received spinal anaesthesia with tetracaine 1%. There was no correlation between the haemodilution and the extent of sensory analgesia. These results support the view that low arterial pressure alone triggers the increased haemodilution observed during EDA-induced hypotension.