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赵树恩 武广义 郭晓俊

保定市河北大学附属医院麻醉科，保定071000

Effect of Acute Hypervolemic Hemodilution on Cerebral O2 Supply/consumption and Energy Metabolism during General Anesthesia

Shu-en Zhao, Guang-yi Wu, Xiao-jun Guo

Department of Anesthesiology, Affiliated Hospital, <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Hebei University,Baoding 071000,China

ABSTRACT

Objective: To investigate the effect of acute hypervolemic hemodilution(AHH)on cerebral O2 supply/consumption and energy metabolism in patients undergoing elective surgery under general anesthesia.

Methods: Sixteen ASAⅠorⅡ patients (9 male,7 female) aged 45-63 yrs weighing 62-73kg undergoing elective surgery under general anesthesia were enrolled in this study. After induction of general anesthesia was confirmed radial artery was cannulated for BP monitoring and blood sampling. Right internal jugular vein was retrogradely cannulated and advanced cephalad until jugular bulb for blood sampling. AHH was conducted by infusing 6% HES 15ml/kg at 50ml/min after induction of general anesthesia. Blood samples were taken from artery and jugular venous bulb simultaneously for blood gas analysis, determination of Hb and Hct, glucose and lactate concentrations before AHH (T0), at 15 min(T1) and 90 min(T2) after AHH was accomplished. Arterial-jugular bulb venous lactate difference(VADL), arterial-jugular bulb venous O2 content difference(Da-vO2) ,cerebral O2 extraction rate(CER02), and glucose extraction rate(CMRglu) were calculated.

Results: At the end of AHH Hb and Hct decreased as compared to the baseline values before AHH. SvO2 was significantly higher, Da-vO2 smaller and CERO2 lower at T1 than at T0.There were no significant differences in BP, HR, CMRglu and VADL at all time points.

Conclusion: AHH can increase cerebral O2 supply and has no significant effect on cerebral glucose metabolism during operation performed under general anesthesia.

Key words: Hemodilution; Oxygen consumpation; Glucose; General anesthesia  

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急性高容量血液稀释（AHH），是术中节约用血的一种重要方式，且有助于改善围手术期的细胞免疫功能^（1，2）。有研究表明AHH可降低血液粘滞性，增加脑血流，改善脑微循环^（3，4）。本研究拟探讨全身麻醉下6％羟乙基淀粉高容量中等程度血液稀释后病人脑代谢状态的变化，为临床提供参考。

资料与方法

1. 一般资料  选择ASAⅠ或Ⅱ级择期手术病人16例，其中男9例，女7例，胃癌根治术11例，中下段食管癌根治术5例，年龄45～63岁，体重62～73kg。术前心、肺功能正常，无贫血及凝血功能异常，无中枢神经疾病。

2. 麻醉与血液稀释方法  麻醉前30min 肌肉注射苯巴比妥钠2mg／kg和阿托品0.01 mg／kg。入室后，监测收缩压（SP）、舒张压（DP）、平均动脉压（MAP）、心率（HR）、脉搏血氧饱和度（SpO2）和心电图，静脉输注乳酸林格氏液8ml～10ml／kg补充术前丢失液体。麻醉诱导时静脉注射芬太尼2～4μg／kg、咪达唑仑0.04mg／kg、丙泊酚1.5mg／kg和维库溴铵0.1mg／kg，行气管插管。吸入异氟醚、间断静脉注射芬太尼、维库溴铵维持麻醉，调整异氟醚呼气末浓度在1％～1.5％。气管插管后，行桡动脉穿刺置管监测血压，右侧颈内静脉逆向穿刺，将16G 静脉导管置入到静内静脉球部。

诱导后进行高容量血液稀释，快速输注6％乙基淀粉（HES，批号：06120121,北京费森尤斯卡比医药有限公司）15ml／kg，输液速率为50 ml／min。术中尿液及创面蒸发量以乳酸林格氏液补充，失血量以等量6％羟乙基淀粉补充。

3. 样本采集  术中应用S／5麻醉监护仪（Datex-Ohmeda division,Instrumentarium Corp，芬兰）连续监测SP、DP、HR、SpO₂、心电图和呼气末二氧化碳分压（PETCO₂ ）；分别于稀释前即刻（T₀）、稀释后15min（T₁）、90min（T₂）、采取桡动脉和颈内静脉球血，应用i-STAT血气分析仪（Abbott公司，美国）进行血气分析、动脉血乳酸浓度（LACa）、颈内静脉血乳酸浓度（LACv）、颈静脉血pH值（pHv）、颈静脉血CO₂分压（PvCO₂）、颈内静脉血氧饱和度（SvO₂）、颈内静脉血氧分压（PvO₂）、Hct、Hb、动静脉血糖及电解质，记录总出血量。并计算以下参数：动脉-颈内静脉血糖差[D（a-v）BG]；动脉-颈内静脉血乳酸浓度差（VADL）；动脉-颈内静脉血氧含量差[D(a-v)O₂]；脑氧摄取率（CERO₂）；脑葡萄糖摄取率（CMRGlu）。

4. 统计学处理  应用SPSS10.0统计软件进行分析，计量资料以均数±标准差（±s）表示，比较采用双因素方差分析，p＜0.05为差异有统计学意义。