Spinal anaesthesia with glucose-free 0.5% bupivacaine: effects of different volumes

The effects of different volumes (1.5, 2, 3, and 4 ml) of glucose-free 0.5% bupivacaine used for spinal anaesthesia were compared in 40 patients scheduled for urological surgery. The blocks were performed with the patients in the sitting position. The time to maximum cephalad spread of analgesia varied between 13 and 18.5 min. A significant difference was found in cephalad spread between the 1.5-and 2-ml groups and the 3-and 4-ml groups. The duration of analgesia increased, the time to complete motor blockade of the lower limbs decreased and the frequency of complete motor blockade increased with increasing volume. Spinal anaesthesia with 3-4 ml of glucose-free 0.5% bupivacaine proved satisfactory for transurethral resection of the prostate.