[Bupivacaine 0.5% CO2 in spinal anesthesia]

The clinical usage of 0.5% bupivacaine-CO2 for spinal anaesthesia was tested in 45 patients. The use of bupivacaine CO2 is safe, segmental dificits were not observed. Compared to bupivacaine-HCl the latency period is shorter (7.7 min), whereas the duration of maximal analgesic spread (105 +/- 31 min) is identical. 93% of the patients had a complete motor blockade. The solubility of bupivacaine-CO2 in CSF (1.75 mg ml-1) is more than double the solubility of bupivacaine-HCl (0.8 mg ml-1), thus lowering the risk of precipitation.