Curatolo M, Petersen-Felix S, Arendt-Nielsen L, Lauber R, Högström H, Scaramozzino P, Luginbühl M, Sieber T J, Zbinden A M
Department of Anesthesiology and Intensive Care, University of Bern, Inselspital, Switzerland.
Anesth Analg. 1998 Feb;86(2):341-7. doi: 10.1097/00000539-199802000-00024.
It is controversial whether adding CO2 or sodium bicarbonate to local anesthetics enhances the depth of epidural blockade. Repeated electrical stimulation is a reliable test for assessing epidural analgesia and evokes temporal summation. We used this test to investigate the analgesic effect of lidocaine, with or without CO2 or bicarbonate. Twenty-four patients undergoing epidural blockade with 20 mL lidocaine 2% at L2-3 were randomly divided into three groups: lidocaine hydrochloride, lidocaine CO2, and lidocaine plus 2 mL sodium bicarbonate 8.4%. Pain threshold after repeated electrical stimulation (five impulses at 2 Hz), pinprick, and cold test were performed at S1 and L4. Motor block was assessed. The addition of bicarbonate resulted in higher pain thresholds (P < 0.0001), faster onset of action (P = 0.009), and higher degree of motor block (P = 0.004) compared with lidocaine hydrochloride. We found no significant differences between lidocaine CO2 and hydrochloride. Most of these results were not confirmed by pinprick and cold tests. We conclude that the addition of sodium bicarbonate to lidocaine enhances the depth of epidural blockade, increases inhibition of temporal summation, and hastens the onset of block. Pinprick and cold are inadequate tests for comparing drugs for epidural anesthesia.
We measured pain perception during epidural anesthesia by delivering electrical stimuli to the knee and foot. We found that the addition of sodium bicarbonate to the local anesthetic lidocaine enhances analgesia. We observed no effect of adding carbon dioxide to lidocaine.
在局部麻醉剂中添加二氧化碳或碳酸氢钠是否能增强硬膜外阻滞的深度存在争议。重复电刺激是评估硬膜外镇痛效果并引发时间总和的可靠测试。我们使用该测试来研究利多卡因（添加或不添加二氧化碳或碳酸氢钠）的镇痛效果。24例在L2-3节段接受20 mL 2%利多卡因硬膜外阻滞的患者被随机分为三组：盐酸利多卡因组、利多卡因二氧化碳组和利多卡因加2 mL 8.4%碳酸氢钠组。在S1和L4节段进行重复电刺激（2 Hz下5次脉冲）、针刺和冷试验后的疼痛阈值测试，并评估运动阻滞情况。与盐酸利多卡因相比，添加碳酸氢钠导致更高的疼痛阈值（P < 0.0001）、更快的起效时间（P = 0.009）和更高程度的运动阻滞（P = 0.004）。我们发现利多卡因二氧化碳组和盐酸利多卡因组之间无显著差异。这些结果大多未被针刺和冷试验所证实。我们得出结论，在利多卡因中添加碳酸氢钠可增强硬膜外阻滞的深度，增加对时间总和的抑制，并加速阻滞的起效。针刺和冷试验不足以比较用于硬膜外麻醉的药物。
我们通过向膝盖和足部施加电刺激来测量硬膜外麻醉期间的疼痛感知。我们发现向局部麻醉剂利多卡因中添加碳酸氢钠可增强镇痛效果。我们观察到向利多卡因中添加二氧化碳没有效果。
