The effect of a lidocaine test dose on analgesia and mobility after an epidural combination of neostigmine and sufentanil in early labor.

We previously demonstrated the effectiveness of epidural sufentanil and the cholinesterase inhibitor, neostigmine, to initiate selective labor analgesia. Because the traditional lidocaine plus epinephrine test dose (TD) may alter the effect of subsequent epidural drugs, we undertook this investigation to evaluate the impact of a lidocaine TD on analgesia from a combination of epidural neostigmine plus sufentanil administered in early labor. Eighty healthy parturients were randomly allocated to two groups to receive a 3 mL-TD, either lidocaine 2%-epinephrine (1:200,000) or saline-epinephrine (1:200,000), followed 3 min later by epidural neostigmine 500 microg plus sufentanil 10 microg. Pain scores were recorded for 30 min after injection, as was the time elapsed from initial bolus until request for supplemental analgesia. Thirty minutes after injection, adequacy of motor function was evaluated by the parturient's ability to sit, stand up, bend her knees, and walk. Lidocaine TD hastened the onset (5 min vs 15 min) and increased duration (122 +/- 53 min vs 98 +/- 54 min; P = 0.02) of analgesia from epidural neostigmine plus sufentanil bolus. In contrast, the TD did not significantly impair the ability to sit, stand up, or bend the knees. The ability to ambulate, however, was reduced (57% vs 82%; P = 0.04). In conclusion, a traditional lidocaine TD significantly enhances the analgesic effect from the epidural neostigmine plus sufentanil combination, but affects ambulation in early labor