Spinal anaesthesia for caesarean section. The use of 0.5% bupivacaine.

Subarachnoid anaesthesia was induced with 0.5% bupivacaine 2-3.5 ml in 33 women scheduled for elective Caesarean section. Three patients failed to develop adequate analgesia with bupivacaine but were managed satisfactorily with heavy cinchocaine. All the other patients developed adequate analgesia eventually. Since the spread of analgesia was uniquely dependent on posture a new hypothesis is presented to explain the distribution of intrathecal anaesthetic drugs in late pregnancy.