Mixture of bupivacaine 0.5% and hyperbaric mepivacaine 4% for spinal anaesthesia.

Recent research shows that using more than 12.5 mg bubivacaine for spinal block may possibly be harmful. A dose of 12.5 mg isobaric bupivacain does not always establish a spinal anaesthesia sufficient for hip or lower abdominal surgery. However short acting local anaesthetics of sufficient effectiveness usually do not last long enough for those operations. We evaluated a method using the subarachnoid injection of 2 to 3 (4) ml of an equal parts mixture of isobaric bupivacain 0.5% and hyperbaric mepivacaine 4%. We generally achieved good spinal anaesthesia with quick onset and long duration of action making longer operations such as total hip endoprothesis possible. The duration of action was longer (130 min) than that of plain mepivacaine (90 min) and shorter than that of plain bupivacain.