背景:术中可以使用四组(TOF)模式的周围神经刺激来评估神经肌肉阻滞的深度并确认从神经肌肉阻断剂(NMBAs)中恢复。由于患者的大小,定量监测在婴儿和儿童中可能具有挑战性,设备技术,对监测点的访问有限。尽管内收肌是首选的监测部位,当手不可用时,脚是一种选择。然而,关于这两个部位的比较性诱发神经肌肉反应的信息很少。
方法:在知情同意后对接受需要NMBA给药的住院手术的儿科患者进行研究。同时对每个参与者进行肌电图(EMG)监测(尺神经,肌腱内收肌)和足(胫骨后神经,幻觉短屈肌)。
结果:研究了50名平均年龄为3.0±标准差(SD)2.9岁的患者。足部TOF的基线第一次抽搐幅度(T1)(12.46mV)比手部高4.47mV(P<0.0001)。NMBA给药前的基线TOF比率(TOFR)和sugammadex拮抗后的最大TOFR在2个部位没有差异。与手相比,脚部的T1下降到基线值(T1)的10%或5%的开始时间延迟了约90秒(均P=0.014)。脚部的TOFR恢复(TOFR≥0.9)比手部达到该阈值时晚191秒(P=.017)。在对抗之后,T1未返回其基线值,肌电图监测的典型发现,但是手部和足部的恢复分数(恢复时的最大T1除以基线T1)没有不同,分别为0.81和0.77(P=.68)。在回收时达到的最终TOFR约为100%,并且在2个位点之间没有差异。
结论:尽管这项针对幼儿的研究证明了TOF监测的可行性,神经肌肉阻滞深度的解释需要考虑与手部相比,足部TOFR的延迟发作和延迟恢复.监测脚时达到这些终点的延迟可能会影响气管插管的时机以及评估神经肌肉阻滞的充分恢复以允许气管拔管(即,TOFR≥0.9)。
BACKGROUND: Peripheral nerve stimulation with a train-of-four (TOF) pattern can be used intraoperatively to evaluate the depth of neuromuscular block and confirm recovery from neuromuscular blocking agents (NMBAs). Quantitative monitoring can be challenging in infants and children due to patient size, equipment technology, and limited access to monitoring sites. Although the adductor pollicis muscle is the preferred site of monitoring, the foot is an alternative when the hands are unavailable. However, there is little information on comparative evoked neuromuscular responses at those 2 sites.
METHODS: Pediatric patients undergoing inpatient surgery requiring NMBA administration were studied after informed consent. Electromyographic (EMG) monitoring was performed simultaneously in each participant at the hand (ulnar nerve, adductor pollicis muscle) and the foot (posterior tibial nerve, flexor hallucis brevis muscle).
RESULTS: Fifty patients with a mean age of 3.0 ± standard deviation (SD) 2.9 years were studied. The baseline first twitch amplitude (T1) of TOF at the foot (12.46 mV) was 4.47 mV higher than at the hand (P <.0001). The baseline TOF ratio (TOFR) before NMBA administration and the maximum TOFR after antagonism with sugammadex were not different at the 2 sites. The onset time until the T1 decreased to 10% or 5% of the baseline value (T1) was delayed by approximately 90 seconds (both P =.014) at the foot compared with the hand. The TOFR at the foot recovered (TOFR ≥0.9) 191 seconds later than when this threshold was achieved at the hand (P =.017). After antagonism, T1 did not return to its baseline value, a typical finding with EMG monitoring, but the fractional recovery (maximum T1 at recovery divided by the baseline T1) at the hand and foot was not different, 0.81 and 0.77, respectively (P =.68). The final TOFR achieved at recovery was approximately 100% and was not different between the 2 sites.
CONCLUSIONS: Although this study in young children demonstrated the feasibility of TOF monitoring, interpretation of the depth of neuromuscular block needs to consider the delayed onset and the delayed recovery of TOFR at the foot compared to the hand. The delay in achieving these end points when monitoring the foot may impact the timing of tracheal intubation and assessment of adequate recovery of neuromuscular block to allow tracheal extubation (ie, TOFR ≥0.9).