Department of Anaesthesiology, Nihon University School of Medicine, Tokyo, Japan.
Acta Anaesthesiol Scand. 2012 Feb;56(2):236-9. doi: 10.1111/j.1399-6576.2011.02605.x.
Increasing age is associated with a longer duration of action of neuromuscular block. The aim of this study was to determine the influence of ageing on the recovery of the post-tetanic count (PTC) from rocuronium-induced neuromuscular block.
Twenty-two younger (20-60 years) and 22 older (> 70 years) patients were enrolled in this study. After induction of anaesthesia with fentanyl and propofol, all patients initially received 1 mg/kg rocuronium and neuromuscular block were evaluated by contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation using an acceleromyograph. Subsequently, intense rocuronium-induced block was determined every 6 min using the PTC during 1.0-1.5% sevoflurane and remifentanil anaesthesia. When the first response to the PTC stimulus was detected, 0.2 mg/kg rocuronium was additionally administered, and again, spontaneous recovery of neuromuscular function was monitored until the first response to the PTC reappeared.
Median values (range) of the times from the administration of 1 mg/kg and 0.2 mg/kg rocuronium until recovery of the first detectable PTC were significantly longer in the older [51.0 (27-100) min, P < 0.0001 and 30.0 (12-66) min, P = 0.0036, respectively] than the younger patients [31.5 (21-45) min and 18.0 (12-36) min, respectively].
The times from rocuronium injection to reappearance of the first response to PTC stimulation are approximately twofold longer and more variable in older than younger patients. Hence, the dosing interval of rocuronium should be adjusted using neuromuscular monitoring when maintaining intense neuromuscular block, especially in older patients.
年龄增长与神经肌肉阻滞作用时间延长有关。本研究旨在确定年龄对罗库溴铵诱导的神经肌肉阻滞后强直刺激计数（PTC）恢复的影响。
本研究纳入 22 例年轻（20-60 岁）和 22 例老年（>70 岁）患者。麻醉诱导采用芬太尼和丙泊酚，所有患者初始给予 1mg/kg 罗库溴铵，采用加速度肌描记器评估拇内收肌对尺神经强直刺激串的收缩。随后，在 1.0-1.5%七氟醚和瑞芬太尼麻醉下，每隔 6 分钟使用 PTC 确定强烈的罗库溴铵诱导阻滞。当检测到对 PTC 刺激的首次反应时，给予 0.2mg/kg 罗库溴铵，再次监测神经肌肉功能的自发恢复，直到首次对 PTC 反应再次出现。
给予 1mg/kg 和 0.2mg/kg 罗库溴铵后至首次可检测到 PTC 恢复的时间中位数（范围）在老年患者中明显长于年轻患者[51.0（27-100）min，P<0.0001 和 30.0（12-66）min，P=0.0036]。
与年轻患者相比，老年患者从罗库溴铵注射到 PTC 刺激首次反应恢复的时间大约延长了两倍，且变异性更大。因此，在维持强烈的神经肌肉阻滞时，尤其是在老年患者中，应使用神经肌肉监测来调整罗库溴铵的给药间隔。
