Arendt-Nielsen L, Oberg B, Bjerring P
Department of Medical Informatics, Aalborg University, Denmark.
Reg Anesth. 1990 Jul-Aug;15(4):186-93.
The significance of ischemia-producing intravenous regional anesthesia (IVRA) was investigated using isotonic saline for injection. The possible analgesic effect of morphine was tested by injecting 40 ml morphine hydrochloride 0.01% for IVRA. Analgesia was evaluated subjectively by measuring the thresholds (warmth and pain) to laser stimulation and objectively by measuring the brain potentials (amplitude and latency) evoked by brief laser stimuli. Morphine and saline produced total pain alleviation after 30 minutes of IVRA. A control study was performed in which 40 ml lidocaine 0.5% and 40 ml prilocaine 0.5% were used for IVRA. This caused an inhibition of the laser-induced pain after 5-10 minutes. After the deflation of the cuff, the thresholds and the brain potentials recovered rapidly. No differences in the efficacy of lidocaine or prilocaine were observed. It is concluded that 30 minutes of tourniquet application is sufficient to cause analgesia and that morphine does not provide more adequate analgesia than saline when used for IVRA.
使用等渗盐水注射来研究产生缺血的静脉区域麻醉（IVRA）的意义。通过注射40毫升0.01%的盐酸吗啡用于IVRA来测试吗啡可能的镇痛效果。通过测量对激光刺激的阈值（热觉和痛觉）主观评估镇痛效果，并通过测量短暂激光刺激诱发的脑电位（振幅和潜伏期）客观评估镇痛效果。吗啡和盐水在IVRA 30分钟后均产生了完全的疼痛缓解。进行了一项对照研究，其中使用40毫升0.5%的利多卡因和40毫升0.5%的丙胺卡因进行IVRA。这在5 - 10分钟后导致了对激光诱导疼痛的抑制。松开袖带后，阈值和脑电位迅速恢复。未观察到利多卡因或丙胺卡因在疗效上的差异。得出的结论是，应用止血带30分钟足以产生镇痛效果，并且当用于IVRA时，吗啡并不比盐水提供更充分的镇痛效果。
