Cooper R A, Mirakhur R K, Elliott P, McCarthy G J
Department of Anaesthetics, Queen's University, Belfast, Northern Ireland.
Can J Anaesth. 1992 Feb;39(2):139-42. doi: 10.1007/BF03008644.
The potency of ORG 9426, a new nondepolarising muscle relaxant, has been estimated using two different modes of nerve stimulation in patients anaesthetised with thiopentone, nitrous oxide-oxygen and intravenous fentanyl. The force of contraction of adductor pollicis was measured following a single twitch (ST) at 0.1 Hz or a train-of-four (TOF) mode of stimulation at 2 Hz every ten seconds. Dose-response curves were constructed using a single-dose method. The ED50, ED90 and ED95 were 147,272 and 305 micrograms.kg-1 respectively using the ST mode and 125,230 and 257 micrograms.kg-1 using the TOF mode of stimulation. The ED50S were not significantly different but the differences between ED90S and ED95S were significant (P less than 0.05) indicating greater sensitivity of the neuromuscular junction using TOF stimulation. The results of this study suggest that the information obtained by single-twitch stimulation is not the same as that obtained from the first response of the TOF stimulation, suggesting apparently increased sensitivity (and apparently greater potency) with the TOF mode of stimulation. Org 9426 appears to be a drug with relatively low potency.
新型非去极化肌肉松弛剂ORG 9426的效能，已在使用硫喷妥钠、氧化亚氮 - 氧气和静脉注射芬太尼麻醉的患者中，通过两种不同的神经刺激模式进行了评估。在以0.1Hz频率进行单次颤搐（ST）刺激或以每十秒2Hz频率进行四个成串刺激（TOF）模式刺激后，测量拇内收肌的收缩力。采用单剂量法构建剂量 - 反应曲线。使用ST模式时，ED50、ED90和ED95分别为147、272和305微克·千克-1；使用TOF刺激模式时，分别为125、230和257微克·千克-1。ED50没有显著差异，但ED90和ED95之间的差异显著（P小于0.05），表明使用TOF刺激时神经肌肉接头的敏感性更高。本研究结果表明，单次颤搐刺激获得的信息与TOF刺激的首次反应获得的信息不同，这表明TOF刺激模式下明显提高了敏感性（且效能明显更高）。ORG 9426似乎是一种效能相对较低的药物。
