老年患者术中6%羟乙基淀粉急性高容量血液稀释的可行性

Feasibility of acute hypervolemic hemodllution with hyuroxyethyl starch in the elderly patients during major surgery

目的 探讨急性高容量血液稀释(AHH)在老年患者术中应用的可行性。方法 选择肝脏择期手术的成年病人24例,ASA I-Ⅱ级,无心肺疾患。根据年龄分成A组(n=12,年龄≥65岁)和B组(n=12,年龄≤55岁)。两组患者均在硬膜外复合全麻下实施AHH,常规全麻诱导后,经中心静脉输注预温的6％羟乙基淀粉(6％HES,200/0.5)15 ml/kg。用HemoSonicTM100血液动力学监测仪连续监测CO、SV、HR、SVR和血流加速度(ACC);并监测MAP、CVP、ECG、SpO2、乳酸、COP、Hct、T和动脉血气的变化。分别在麻醉平稳后5 min,AHH后即刻及术毕记录上述数据,同时记录术中输液量、失血量及输血量,术后第一天复查血常规。结果 AHH后,两组患者的MAP、HR、和ACC与血液稀释前相比无显著性改变,而CO、SV及CVP明显升高,SVR明显下降(P<0.05)。A和B组CO、SV、CVP变化幅度差异无显著性(P>0.05)。动脉血pH值、乳酸及COP在AHH前后无明显改变,其组间比较P>0.05。两组患者术中输液量及失血量差异亦无显著性。结论 年龄并不是影响AHH实施的主要因素;一般情况良好、无心肺疾患的老年患者,在硬膜外复合全麻下,用6％HES按15ml/kg行快速扩容实施AHH是安全可行的。

Objective To evaluate the feasibility of acute hypervolemic hemodilution (AHH) with 6% hydroxyethyl starch in the elderly patients during major surgery performed under combined general-epidural anesthesia. Methods Twenty-four ASA I - II patients without cardiac and pulmonary disease undergoing elective liver operation were divided into 2 groups according to their ages: group A included patients aged over 65 yr ( n = 12) and group B aged less than 55 yr ( n = 12) . The patients were premedicated with intramuscular sodium phenobarbital 0.1 g and atropine 0.3 mg. Epidural catheter was placed at T8-9 and 2 % lidocaine 3-4 ml was given before induction of general anesthesia. Anesthesia was induced with fentanyl 4μg·kg-1 , thiopentone 4 - 5 mg·kg-1 and succinylcholine 1.5 mg·kg-1 . After tracheal intubation the patients were mechanically ventilated. PETCO2 was maintained at 35 - 40 mm Hg. Anesthesia was maintained with isoflurane inhalation (0.6-0.8 MAC) and intermittent iv boluses of vecuronium. After induction of anesthesia, 0.375% bupivacaine 8 - 10 ml was given epidurally. AHH was performed with pre-warmed 6% hydroxyethyl starch (200/0.5) 15 ml·kg-1 infused at a rate of 50 ml·min-1 before skin incision. Radial artery was cannulated for direct BP monitoring and internal jugular vein was cannulated for CVP monitoring. Cardiac output ( CO), stroke volume ( SV), ACC (max acceleration during systol), HR and SVR were continuously monitored using transesophageal Doppler (HemoSonic?100) . Arterial blood samples were taken for blood gas analysis and determination of lactic acid (Lac) , colloid osmotic pressure (COP) and Hct, Hb before and after AHH and at the end of operation. Routine blood test was checked 1 day after operation. The volume of solution infused, blood loss and blood transfusion were recorded during the operation.Results Hct was reduced from 39.2%±2.6% before AHH to 30.5%±2.1% after AHH in the elderly patient group (A) and from 40.2% ?± 1.7% to 32.8%±2.0% in group B. There was no significant change in MAP, HR and ACC after AHH (P > 0.05) but CO, SV and CVP increased and SVR decreased significantly after AHH in both groups as compared with those before AHH. pH, Lac and COP did not change significantly after AHH. There was no significant difference in the volume of solution infused, blood loss, CO, SV, CVP and SVR between the two groups. Conclusion Age is not a primary factor negating the use of AHH. Under combined general-epidural anesthesia AHH with 6% hydroxyethyl starch (15 ml·kg-1 ) can be well tolerated by the elderly patients without cardiac and pulmonary disease.