Rhee Won Ji, Lee Seung Yoon, Lee Ji Hyeon, Choi So Ron, Lee Seung-Cheol, Lee Jong Hwan, Lee Soo-Il
Department of Anesthesiology and Pain Medicine, Dong-eui Medical Center, Busan, Korea.
Department of Anesthesiology and Pain Medicine, Dong-A University College of Medicine, Busan, Korea.
Korean J Anesthesiol. 2015 Feb;68(1):50-61. doi: 10.4097/kjae.2015.68.1.50. Epub 2015 Jan 28.
Magnesium, ropivacaine, gentamicin, and rocuronium block neuromuscular (NM) transmission by different mechanisms. Therefore, concurrent administration of these agents may induce prolonged muscle paralysis via synergistic interaction. This study investigated the efficacy and safety of NM block caused by the administration of high concentrations of magnesium in combination with ropivacaine, gentamicin, and rocuronium.
Eighty-three left phrenic nerve-hemidiaphragms from male SD rats (150-250 g) were hung in Krebs solution. Three consecutive single twitch tension (ST, 0.1 Hz) and one tetanic tension (TT, 50 Hz for 1.9 s) were obtained before drug application and at each new drug concentration. The concentration of MgCl2 and MgSO4 in Krebs solution was increased until an 80 to 90% reduction in ST was reached. To test the effects of combinations of NM agents, a Krebs solution was premixed with MgCl2 alone, MgCl2 and ropivacaine, or MgCl2, ropivacaine, and gentamicin. The concentration of ropivacaine, gentamicin, or rocuronium was then progressively increased until an 80 to 90% reduction in ST was reached. The effective concentrations were estimated with a probit model.
The potency of MgCl2 was greater than that of MgSO4, and pretreatment with MgCl2 increased the potency of gentamicin and rocuronium. Unexpectedly, MgCl2 did not potentiate ropivacaine, and the potency of gentamicin and rocuronium failed to show an increase when premixed with 0.5 µM ropivacaine.
The concomitant administration of high concentrations of magnesium and ropivacaine together with clinically relevant concentrations of gentamicin or rocuronium potentiated NM blockade but not with clinically relevant concentrations of ropivacaine.
镁、罗哌卡因、庆大霉素和罗库溴铵通过不同机制阻断神经肌肉（NM）传递。因此，同时给予这些药物可能通过协同相互作用导致肌肉麻痹时间延长。本研究调查了高浓度镁与罗哌卡因、庆大霉素和罗库溴铵联合给药引起的NM阻滞的有效性和安全性。
将83个来自雄性SD大鼠（150 - 250 g）的左膈神经 - 半膈肌悬挂在 Krebs 溶液中。在给药前以及每个新的药物浓度下，获取连续三次单颤搐张力（ST，0.1 Hz）和一次强直张力（TT，50 Hz 持续1.9 s）。增加 Krebs 溶液中 MgCl₂ 和 MgSO₄ 的浓度，直至 ST 降低80%至90%。为测试NM药物组合的效果，将 Krebs 溶液单独与 MgCl₂、MgCl₂ 和罗哌卡因或 MgCl₂、罗哌卡因和庆大霉素预混合。然后逐渐增加罗哌卡因、庆大霉素或罗库溴铵的浓度，直至 ST 降低80%至90%。用概率模型估计有效浓度。
MgCl₂ 的效力大于 MgSO₄，用 MgCl₂ 预处理可增加庆大霉素和罗库溴铵的效力。出乎意料的是，MgCl₂ 并未增强罗哌卡因的效力，并且当与0.5 μM 罗哌卡因预混合时，庆大霉素和罗库溴铵的效力未显示增加。
高浓度镁与罗哌卡因以及临床相关浓度的庆大霉素或罗库溴铵联合给药可增强NM阻滞，但与临床相关浓度的罗哌卡因联合给药则不然。
