Itoh H, Shibata K, Nitta S, Kobayashi T
Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Kanazawa University, Japan.
Can J Anaesth. 2000 Oct;47(10):950-5. doi: 10.1007/BF03024864.
To clarify the relationship between neuromuscular block and train-of-four fade and to investigate the causes of these drug-dependent differences, we compared the neuromuscular block and TOF fade after pancuronium, vecuronium and rocuronium.
In 24 anesthetized rats, the sciatic nerve was stimulated, and the twitch of left tibialis anterior muscle was recorded. After T1 (first twitch response) was kept constant at 95% block by administration of pancuronium, vecuronium, or rocuronium (n=8, in each), the TOF fade was measured when T1 block was decreased to 40% and 20%. In addition, using 24 phrenic nerve-diaphragm preparations, the fade was measured when the T1 block increased to 20% and 40% by titrating of either one of the three drugs (n=8, in each).
In in vivo experiments, the fade produced by pancuronium was greater than that by vecuronium or rocuronium when T1 block was at 40% (81 +/- 9 vs 63 +/- 15 and 63 +/- 6%, respectively) and at 20% (66 +/- 13 vs 34 +/- 17 and 40 +/- 6%, respectively). In contrast, in in vitro experiments, the differences did not reach significant levels among the three drugs either at 20% (32 +/- 19 vs 33 +/- 10 and 32 +/- 17%) or 40% of block (62 +/- 29 vs 65 +/- 14 and 55 +/- 14%).
For vecuronium and rocuronium, the results were similar in vivo and in vitro. For pancuronium, fade was greater in vivo. These results suggest that different neuromuscular blocking agent have different relationships between the fade and the block. In vitro results might not be the same as in vivo, possibly due to pharmacokinetic differences.
为阐明神经肌肉阻滞与四个成串刺激衰减之间的关系，并探究这些药物依赖性差异的原因，我们比较了泮库溴铵、维库溴铵和罗库溴铵后的神经肌肉阻滞及四个成串刺激衰减情况。
在24只麻醉大鼠中，刺激坐骨神经，记录左胫前肌的抽搐反应。在分别给予泮库溴铵、维库溴铵或罗库溴铵使T1（首次抽搐反应）保持在95%阻滞水平（每组n = 8）后，当T1阻滞降至40%和20%时测量四个成串刺激衰减情况。此外，使用24个膈神经 - 膈肌标本，通过滴定三种药物中的任一种使T1阻滞增加至20%和40%时测量衰减情况（每组n = 8）。
在体内实验中，当T1阻滞为40%时（分别为81±9%对63±15%和63±6%）以及20%时（分别为66±13%对34±17%和40±6%），泮库溴铵产生的衰减大于维库溴铵或罗库溴铵。相比之下，在体外实验中，在20%阻滞水平（32±19%对33±10%和32±17%）或40%阻滞水平（62±29%对65±14%和55±14%）时，三种药物之间的差异未达到显著水平。
对于维库溴铵和罗库溴铵，体内和体外结果相似。对于泮库溴铵，体内衰减更大。这些结果表明，不同的神经肌肉阻滞剂在衰减和阻滞之间具有不同的关系。体外结果可能与体内不同，这可能是由于药代动力学差异所致。
