Sage D J, Feldman H S, Arthur G R, Datta S, Ferretti A M, Norway S B, Covino B G
Anesth Analg. 1984 Jan;63(1):1-7.
In an isolated guinea pig atrial preparation, the bathing solution pH, PO2, and PCO2 were manipulated to mimic normal, acidotic, and hypoxic conditions. The effect of lidocaine and bupivacaine on spontaneous heart rate (HR) and contractile force (CF) was determined for 60 min under conditions of normal pH, PO2, and PCO2. Lidocaine (50 micrograms/ml) reduced HR by a maximum of 34.2 +/- 1.5% and CF by 38.9 +/- 8.1% (mean +/- SEM). Bupivacaine (5 micrograms/ml) reduced HR by a maximum of 30.1 +/- 1.9% and CF by 48.0 +/- 6.5%. Bupivacaine (10 micrograms/ml) caused a maximum HR reduction of 61.7 +/- 9.5% and CF reduction of 66.0 +/- 8.6%. Hypoxia or metabolic or respiratory acidosis did not further enhance the local anesthetic induced atrial depression. However, conditions of combined acidosis/hypoxia, while not significantly altering the HR and CF depression caused by lidocaine, did enhance bupivacaine-induced depression of HR and CF (93.6 +/- 6.3% and 95.2 +/- 4.8%, respectively). The effect of a protein-free bathing solution on the relative toxicities of lidocaine and bupivacaine is discussed.
在一个离体豚鼠心房标本中，对浴液的pH值、氧分压（PO₂）和二氧化碳分压（PCO₂）进行调控，以模拟正常、酸中毒和低氧状态。在正常pH值、PO₂和PCO₂条件下，测定利多卡因和布比卡因对自发心率（HR）和收缩力（CF）的影响，持续60分钟。利多卡因（50微克/毫升）使HR最大降低34.2±1.5%，CF降低38.9±8.1%（平均值±标准误）。布比卡因（5微克/毫升）使HR最大降低30.1±1.9%，CF降低48.0±6.5%。布比卡因（10微克/毫升）使HR最大降低61.7±9.5%，CF降低66.0±8.6%。低氧或代谢性或呼吸性酸中毒并未进一步增强局部麻醉药引起的心房抑制。然而，酸中毒/低氧联合状态虽然未显著改变利多卡因引起的HR和CF降低，但确实增强了布比卡因引起的HR和CF降低（分别为93.6±6.3%和95.2±4.8%）。文中讨论了无蛋白浴液对利多卡因和布比卡因相对毒性的影响。
