Xue F S, Liao X, Liu J H, Zhang Y M, An G, Luo L K
Department of Anaesthesia, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
Acta Anaesthesiol Scand. 2000 Feb;44(2):163-9. doi: 10.1034/j.1399-6576.2000.440206.x.
Acute normovolaemic haemodilution is a common method to save and avoid homologous blood transfusion during surgery. The aim of this study was to evaluate the influence of acute isovolaemic haemodilution on the dose-response and time-course of action of atracurium.
We studied 25 patients undergoing acute isovolaemic haemodilution during surgery and 25 patients not receiving haemodilution as a control group. All patients were ASA grade I and aged 18-54 yr. The haemodilution patients underwent major elective plastic surgery with an anticipated surgical blood loss of more than 600 ml, and the control patients underwent elective superficial plastic surgery with an anticipated surgical blood loss of less than 200 ml. Anaesthesia was induced with thiopental 4-6 mg/kg and fentanyl 2-4 microg/kg i.v., and maintained with 60% nitrous oxide in oxygen. After stabilization of anaesthesia, acute isovolaemic haemodilution in the haemodilution group was achieved by drainage of venous blood and an i.v. infusion of lactated Ringer's solution, and 6% dextran, during which haematocrit and haemoglobin decreased from 45.1% to 25.8% and from 147.2 g/l to 91.2 g/l, respectively. When anaesthesia was stable in the control group and haemodilution was completed in the haemodilution group, neuromuscular function was assessed by measuring with accelerography the response of the adductor pollicis muscle to supramaximal train-of-four (TOF) stimuli every 12 s to the ulnar nerve at the wrist via surface electrodes. The dose-response relationships of atracurium in the two groups were determined by the cumulative dose-response technique.
The results showed that during haemodilution, the dose-response curve of atracurium was shifted to the left in a parallel fashion and the potency of atracurium was increased. In patients undergoing haemodilution, ED50, ED90 and ED95 of atracurium were decreased by 25-33%, and duration of action was increased by 21-48% following administration of the same dose (mg/kg), as compared with patients not undergoing haemodilution.
We concluded that the patients undergoing acute isovolaemic haemodilution were about 30% more sensitive to neuromuscular blockade of atracurium and had a longer duration after administration of the same dose (microg/kg) than the control patients. Care must be taken with this problem when atracurium is used as a muscle relaxant during acute haemodilution.
急性等容性血液稀释是手术中保存和避免同种异体输血的常用方法。本研究旨在评估急性等容性血液稀释对阿曲库铵剂量反应及作用时效的影响。
我们研究了25例手术中接受急性等容性血液稀释的患者和25例未接受血液稀释的患者作为对照组。所有患者均为ASA I级，年龄在18至54岁之间。血液稀释组患者接受预计失血量超过600 ml的大型择期整形手术，对照组患者接受预计失血量少于200 ml的择期浅表整形手术。静脉注射硫喷妥钠4 - 6 mg/kg和芬太尼2 - 4 μg/kg诱导麻醉，并用60%氧化亚氮-氧气维持麻醉。麻醉稳定后，血液稀释组通过引流静脉血并静脉输注乳酸林格氏液和6%右旋糖酐实现急性等容性血液稀释，在此期间血细胞比容和血红蛋白分别从45.1%降至25.8%，从147.2 g/l降至91.2 g/l。当对照组麻醉稳定且血液稀释组完成血液稀释后，通过加速度描记法每12秒测量一次拇内收肌对经腕部表面电极给予尺神经的超强四个成串刺激（TOF）的反应，评估神经肌肉功能。采用累积剂量反应技术确定两组中阿曲库铵的剂量反应关系。
结果显示，在血液稀释期间，阿曲库铵的剂量反应曲线平行左移，阿曲库铵的效能增加。与未进行血液稀释的患者相比，进行血液稀释的患者给予相同剂量（mg/kg）的阿曲库铵后，其ED50、ED90和ED95降低了25% - 33%，作用持续时间延长了21% - 48%。
我们得出结论，与对照组患者相比，接受急性等容性血液稀释的患者对阿曲库铵神经肌肉阻滞的敏感性高约30%，给予相同剂量（μg/kg）后作用持续时间更长。在急性血液稀释期间使用阿曲库铵作为肌肉松弛剂时，必须注意这个问题。
