Abdulatif M, el-Sanabary M
Department of Anaesthesia, Faculty of Medicine, Cairo University, Egypt.
Br J Anaesth. 1997 Jul;79(1):24-8. doi: 10.1093/bja/79.1.24.
We have studied the pattern of blood flow and pharmacodynamic profile of mivacurium-induced block at the adductor pollicis and orbicularis oculi muscles. We studied 30 adult patients anaesthetized with fentanyl, thiopentone, nitrous oxide-isoflurane, and mivacurium 0.2 mg kg-1. Neuromuscular transmission was monitored with accelerometry (TOF Guard, Biometer, Denmark). Blood flow was measured at the two muscles with the use of a laser Doppler flowmeter (Laserflo BPM2, Vasamedics, USA). All patients developed 100% neuromuscular block at the adductor pollicis muscle. Mean maximum neuromuscular block at the orbicularis oculi was 96.4 (SD 3.5)% (ns). Onset time, time required for 25% and 75% recovery of the first twitch in the train-of-four (T1), and a train-of-four ratio (T4/T1) of 90% at the orbicularis oculi were respectively, mean 130.4 (SD 28.5) s, 9.1 (3.2) min, 16.2 (3.9) min and 20.2 (4.3) min and were significantly shorter than the corresponding values at the adductor pollicis: 202.7 (37.2) s, 12.9 (3.9) min, 21.1 (5.1) min and 30.8 (7.4) min. For a given T1, there was significantly less train-of-four fade (T4/T1) at the orbicularis oculi than at the adductor pollicis muscle during recovery. Blood flow was comparable at the two muscles before induction of anaesthesia. Thiopentone significantly increased thenar muscle blood flow from 2.9 (1.5) to 12.3 (6.8) ml 100 g-1 min-1, with a further increase to 22.7 (8.0) ml 100 g-1 min-1 after isoflurane (P < 0.001). Blood flow at the orbicularis oculi was not altered by thiopentone or isoflurane and was consistently lower than that at the adductor pollicis muscle. We conclude that the different pharmacodynamic profiles of mivacurium-induced block at the orbicularis oculi and adductor pollicis muscles were not related primarily to a difference in blood flows.
我们研究了米库氯铵诱导的拇收肌和眼轮匝肌阻滞的血流模式和药效学特征。我们对30例成年患者进行了研究，这些患者接受芬太尼、硫喷妥钠、氧化亚氮-异氟烷麻醉，并给予0.2 mg/kg的米库氯铵。采用加速度计（丹麦Biometer公司的TOF Guard）监测神经肌肉传递。使用激光多普勒血流仪（美国Vasamedics公司的Laserflo BPM2）测量两块肌肉的血流。所有患者拇收肌均出现100%的神经肌肉阻滞。眼轮匝肌的平均最大神经肌肉阻滞为96.4（标准差3.5）%（无显著性差异）。眼轮匝肌的起效时间、四个成串刺激（T1）中第一个颤搐恢复25%和75%所需的时间以及四个成串刺激比值（T4/T1）达到90%时的时间分别为平均130.4（标准差28.5）秒、9.1（3.2）分钟、16.2（3.9）分钟和20.2（4.3）分钟，均显著短于拇收肌的相应值：202.7（37.2）秒、12.9（3.9）分钟、21.1（5.1）分钟和30.8（7.4）分钟。在恢复过程中，对于给定的T1，眼轮匝肌的四个成串刺激衰减（T4/T1）明显小于拇收肌。麻醉诱导前两块肌肉的血流相当。硫喷妥钠使大鱼际肌血流从2.9（1.5）显著增加至12.3（6.8）ml/100g-1·min-1，异氟烷后进一步增加至22.7（8.0）ml/100g-1·min-1（P<0.001）。硫喷妥钠或异氟烷未改变眼轮匝肌的血流，且眼轮匝肌的血流始终低于拇收肌。我们得出结论，米库氯铵诱导的眼轮匝肌和拇收肌阻滞的不同药效学特征主要与血流差异无关。
