Arendt-Nielsen L, Bjerring P, Dahl J B
Department of Medical Informatics, Aalborg University, Denmark.
Acta Anaesthesiol Scand. 1991 Jan;35(1):24-9. doi: 10.1111/j.1399-6576.1991.tb03236.x.
In two double-blind, placebo-controlled investigations, morphine and lidocaine were administered perineurally to the ulnar nerve. Thresholds (warmth and pain) and pain-evoked brain potentials (amplitude and latency) to argon laser stimulation were measured up to 120 min after the injection. Hypalgesia to laser pain was detected 15 min after the injection of morphine and 5 min after the injection of lidocaine. The duration of hypalgesia and analgesia was less than 15 min for morphine and 85 min for the lidocaine injection. Both morphine and lidocaine increased the latency of the brain potentials, which indicates that the same blocking mechanisms could be involved. Pin-prick analgesia was obtained 5 min after the injection of lidocaine, but 15-30 min elapsed before the laser pain was inhibited maximally. Laser pulses can activate larger skin areas than needle pricks, indicating that a central summation of the activity from many cutaneous nociceptors is important in order to obtain a reliable indicator of adequate analgesia.
在两项双盲、安慰剂对照研究中，将吗啡和利多卡因经神经周围注射至尺神经。在注射后长达120分钟内，测量对氩激光刺激的阈值（温热和疼痛）以及疼痛诱发的脑电位（振幅和潜伏期）。注射吗啡后15分钟和注射利多卡因后5分钟检测到对激光疼痛的痛觉减退。吗啡注射后痛觉减退和镇痛的持续时间小于15分钟，利多卡因注射后为85分钟。吗啡和利多卡因均增加了脑电位的潜伏期，这表明可能涉及相同的阻断机制。注射利多卡因后5分钟获得针刺镇痛，但在激光疼痛最大程度受到抑制之前经过了15 - 30分钟。激光脉冲比针刺能激活更大的皮肤区域，这表明来自许多皮肤伤害感受器的活动进行中枢总和对于获得充分镇痛的可靠指标很重要。
