Arvidsson I, Eriksson E, Knutsson E, Arnér S
Orthopedics. 1986 Oct;9(10):1415-9. doi: 10.3928/0147-7447-19861001-13.
The influence of postoperative pain on muscle function, and the possible effect of local anesthetics on the normal muscle function are discussed. The integrated EMG (IEMG) during maximum voluntary contraction of the quadriceps muscle was registered in ten patients the day after undergoing reconstruction of the anterior cruciate ligament. Recordings were taken before, 5, 12, and 20 min to 25 min after epidural injection of 20 ml of 0.25% lidocaine with adrenaline (2.5 micrograms/ml). As pain gradually subsided, IEMG increased a mean of 2,728% 20 min to 25 min after injection (range 425% to 10,068%), compared to initial recordings before anesthesia. This indicates that pain relief plays a significant role in the ability to normally activate the quadriceps muscle after open knee surgery. Neither the Hoffman (H-)reflex, nor maximum voluntary isokinetic muscle torque was appreciably affected by epidural injection of dilute local anesthetics, as tested on two healthy volunteers. Infiltrations of local anesthetics into the distal part of the quadriceps muscle did not affect maximum voluntary isokinetic knee extension torque. From the experiments performed we conclude that it is possible to selectively block pain by injections of local anesthetics into the epidural space, without interfering with normal muscle function. It might thus be possible to prevent some of the postoperative muscle atrophy by using a continuous epidural analgesia for two to three days following surgery, and starting an early active physical therapy program.
本文讨论了术后疼痛对肌肉功能的影响，以及局部麻醉药对正常肌肉功能的可能作用。在10例接受前交叉韧带重建手术的患者术后第一天，记录了股四头肌最大自主收缩时的积分肌电图（IEMG）。在硬膜外注射20ml含肾上腺素（2.5μg/ml）的0.25%利多卡因前、注射后5分钟、12分钟以及20至25分钟进行记录。与麻醉前的初始记录相比，随着疼痛逐渐减轻，注射后20至25分钟IEMG平均增加了2728%（范围为425%至10068%）。这表明疼痛缓解在膝关节开放手术后正常激活股四头肌的能力中起着重要作用。在两名健康志愿者身上进行测试，硬膜外注射稀释的局部麻醉药对霍夫曼（H-）反射和最大自主等速肌肉扭矩均无明显影响。将局部麻醉药注入股四头肌远端对最大自主等速膝关节伸展扭矩没有影响。从所进行的实验中我们得出结论，通过向硬膜外腔注射局部麻醉药有可能选择性地阻断疼痛，而不干扰正常肌肉功能。因此，在手术后使用持续硬膜外镇痛两到三天，并启动早期积极的物理治疗计划，有可能预防一些术后肌肉萎缩。
