Neostigmine Ng Use Of Local Anesthetic Delivery Analgesia

Objective Observing the analgesic effect of neostigmine combined with long acting local anesthetic such as bupivacaine and ropivacaine during the first stage of labor in epidural space, to discuss whether it can be used in clinical or not. It provides theoretical and experimental bases for using suitable epidural analgesic drugs during labor.Method There are three phrases in all. Phrase I, to determine the minimum local analgesic concentration (MLAC) or median effective concentration (EC50) of bupivacaine and ropivacaine, and to compare their relative potencies during the first stage of labor. Phrase II, to determine the concentration of neostigmine for pain relief .Phrase III, primipara enters different groups according to the results from phrases I and II, observing and recording VAPS at different time required, monitoring fetus heart rate and uterine contraction continuously. Bloodsamples from mother's elbow venous were obtained at the following intervals: (1) before analgesia, (2) 30 minutes after analgesia, (3) Disengagement of the fetus.Beta- endorphin and cortisol in plasma are measured. At the same time, Blood gas analysis and blood sugar also were determined from mother's elbow venous and umbilical cord's venous.Results (1) The MLAC of Ropivacaine is 0.1305%w/v；that of bupivacaine is 0.1058%w/v(P<0.01).(2) Neostigmine 0.5 mg and 1mg in epidural space produce better analgesia effect than 1.5mg, besides the incidence of side effect was lower. (3) Group NB produced the same analgesic effect and longer analgesic time without increasing the rate of nursing labor, neither urinary retention nor itch of skin occurred.Conclusion (1) The MLAC of Ropivacaine is 0.1305(95%Cl 0.1198—0.1421)%w/v；that of bupivacaine is 0.1058(95%Cl0.0979—0.1143)%w/v. The relative potencies of Ropivacaine to bupivacaine is about 77%(95%Cl0.63—0.85). (2) Epidural neostigmine can provide analgesia in some degree.(3)Using neostigmine combined bupivacaine for labor analgesia can reduce dose of local analgesia without influencing the analgesia effect, decrease moter-nerve block ,avoid urinary retention and itch of skin and respiratory inhibition caused by opium.