Plain or Hyperbaric Bupivacaine for Spinal Anesthesia

Three ml of bupivacaine 0.5%, either plain or in 8% glucose, was injected intrathecally in three groups of twenty patients. Group 1 received bupivacaine 0.5% plain; group 2 received bupivacaine 0.5% in 8% glucose. Patients in groups 1 and 2 were kept sitting for 3 min after injection. Patients in group 3 received bupivacaine 0.5% in 8% glucose and were placed in the supine horizontal position immediately after injection. Observations of patients in group 3 were observer blind and in groups 1 and 2 double blind. The differences between segmental levels of sensory and temperature loss between groups 1 and 2 and between groups 2 and 3 were statistically not significant. Motor blockade of the lower extremities was more intense in the patients who were kept sitting for 3 min (groups 1 and 2). It is concluded that both solutions are equally suitable for spinal anesthesia, provided patients receiving the plain solution are kept sitting for at least 2 min. When using hyperbaric bupivacaine, posture seems to have no influence on cephalad spread.