Wiklund L, Tucker G T, Engberg G
Acta Anaesthesiol Scand. 1977;21(4):275-81. doi: 10.1111/j.1399-6576.1977.tb01220.x.
The effects of a 20 mg i.v. bolus of ephedrine sulphate on haemodynamics and plasma lidocaine concentrations were evaluated in eight volunteer subjects receiving a constant i.v. infusion of lidocaine HC1 (2 or 4 mg-min-1). Injection of ephedrine caused a significant increase in mean arterial blood pressure, which preceded an elevation of heart rate by about 2 min. Cardiac output and hepatic blood flow, measured at 10 and 20 min after injection, were also increased significantly, while there was a decrease in total peripheral resistance and no change in splanchnic vascular resistance. There were no significant circulatory alterations over the same period in a control group of four subjects on receiving the lidocaine infusion. After ephedrine, the mean splanchnic extraction ratio of lidocaine fell from 0.76 to 0.66 at 10 min, then rose again to 0.71 at 20 min, and these changes were accompanied by a 9% increase in its splanchnic clearance. Extraction and clearance remained unchanged in the control group. The implications of these findings are considered in relation to the use of ephedrine to prevent or treat hypotension after peridural block with local anaesthetic agents.
在8名接受盐酸利多卡因持续静脉输注（2或4mg·min⁻¹）的志愿者中，评估了静脉注射20mg硫酸麻黄碱对血流动力学和血浆利多卡因浓度的影响。注射麻黄碱后，平均动脉血压显著升高，心率升高约2分钟。注射后10分钟和20分钟测得的心输出量和肝血流量也显著增加，而总外周阻力降低，内脏血管阻力无变化。在接受利多卡因输注的4名对照组受试者中，同期未出现明显的循环改变。注射麻黄碱后，利多卡因的平均内脏提取率在10分钟时从0.76降至0.66，然后在20分钟时再次升至0.71，这些变化伴随着其内脏清除率增加9%。对照组的提取率和清除率保持不变。结合使用麻黄碱预防或治疗局部麻醉药硬膜外阻滞术后低血压的情况，对这些发现的意义进行了探讨。
