In a double-blind study of spinal anaesthesia with 0.5% bupivacaine 3 ml with no glucose, 5% glucose or 8% glucose all three solutions gave consistently good nerve blocks. The hyperbaric solutions (5% and 8% glucose) produced a greater cephalad spread and were suitable for lower abdominal surgery, whereas the plain solution (no glucose) seldom affected the thoracic nerves. Cardiovascular changes were more marked with the hyperbaric solutions but only necessitated treatment on two occasions. The duration of block was not affected by baricity and was in the range 140-160 min.

In a randomized study, the incidence of visceral pain was evaluated in 46 patients undergoing elective caesarean section under spinal or epidural anaesthesia with 0.5% bupivacaine. If the patient experienced pain during the operation, a standard visual analogue scale ranging from 0 to 10 was used to assess the degree of pain. Visceral pain occurred in 12/23 patients in the spinal group and in 13/23 patients in the epidural group. In neither group was a correlation found between the cephalad level of analgesia or the intensity of cutaneous analgesia in the sacral region, and the presence of visceral pain.

No abstract

The effects of subarachnoid administration of 0.5% bupivacaine 4 ml in 8%, 5% or 0% glucose were investigated in a double-blind study in 30 women undergoing laparotomy through a lower abdominal incision. The onset time for maximum segmental spread of analgesia was 10-15 min for all solutions. Cephalad segmental spread of analgesia was three to four segments higher with the hyperbaric solutions (T4-5 v. T7-8). Time of onset of complete motor blockade of the lower limbs was 5-10 min for all solutions. The glucose-free solution did not produce sufficient surgical anaesthesia because of too low cephalad spread. Duration of motor blockade generally decreased with increasing glucose concentration, only the hyperbaric solutions providing useful for abdominal surgery, with a duration of 1-1.5 h. Anaesthesia (halothane) was required in seven of 10 patients in the glucose-free group and in five of 20 in the hyperbaric groups. No occurrence of "post-spinal headache" was recorded in the study.

Different volumes (1.5, 2, 3 and 4 ml) of hyperbaric 0.5% bupivacaine (8% glucose) were compared in spinal anaesthesia for urological surgery in 40 patients. The blockade was given with the patient in the sitting position. Two minutes after the injection the patient was placed in the lithotomy position. The time required for maximum cephalad spread of analgesia was about 20 min for all volumes. The maximum cephalad spread was directly related to log volume of the local anaesthetic solution. The onset time for motor blockade of the lower limbs decreased and the frequency increased with increasing volume. Four ml produced complete blockade in all patients. The duration of analgesia increased with increasing volume: 3-4 ml produced analgesia at T8 for 1.5-2.5 h and at L1 for 2-3 h. With this volume, complete motor blockade was obtained for 1.5-2.5 h. Satisfactory surgical anaesthesia for transurethral resection was obtained with 3-4 ml of the local anaesthetic solution.