Neostigmine combined with bupivacaine, clonidine, and sufentanil for spinal labor analgesia

We previously found that spinal clonidine prolongs labor analgesia when com bined with spinal bupivacaine and sufentanil. We sought to determine whethe r the addition of spinal neostigmine to these drugs would further enhance l abor analgesia. By use of a combined spinal/epidural technique, 36 patients were randomized to receive a hyperbaric spinal injection of bupivacaine 2. 5 mg plus clonidine 50 mug and sufentanil 10 mug with or without neostigmin e 10 mug. Pain, maternal hemodynamics, fetal heart rate, nausea, pruritus, sedation, motor block, sensory levels to pinprick, and maternal oxygen satu ration were assessed at regularly specified intervals after spinal injectio n until additional analgesia was requested. The duration of spinal analgesi a was similar between groups (215 +/- 60 min in the Control group versus 20 5 +/- 62 min in the Neostigmine group). Likewise, pain scores, the duration of labor, Apgar scores, and side effects were similar between groups excep t that patients administered neostigmine experienced significantly more nau sea and vomiting (53% vs 7%, P = 0.01). We conclude that spinal neostigmine 10 mug produces severe nausea and does not potentiate the duration of spin al analgesia in laboring women from spinal bupivacaine, clonidine, and sufe ntanil.