【作者】 孙传江；

【导师】 苏跃；

【作者基本信息】 北京市结核病胸部肿瘤研究所 ， 麻醉学， 2004， 硕士

【摘要】 目的 用反向Fick法研究开胸手术围术期氧供需是否平衡以及氧供氧耗关系的变化特点，开胸手术对机体血流动力学的影响。 方法 30例择期行开胸手术的患者常规插管麻醉后采用50％笑气复合静脉异丙酚、异氟醚维持麻醉，采用Hemosonic^TM 100经食道超声多谱勒连续监测心输出量（CO），桡动脉穿刺行有创血压连续监测和动脉血气分析，经颈内静脉放置CVP测压管，同时抽取混合静脉血做血气分析。分别于入室后平卧自主呼吸（T₁）、插管后侧卧位双肺通气15分钟（T₂）、侧卧位单肺通气15分钟（T₃）、侧卧位单肺通气30分钟（T₄）、侧卧位单肺通气60分钟（T₅）、关胸后双肺通气10分钟（T₆），分别抽取桡动脉血和混合静脉血做血气分析，同时抽取动脉血2ml测定动脉血乳酸浓度（ABL）。根据标准公式计算氧供（DO₂）、氧耗（VO₂）、氧摄取率（ERO₂），观察在6个时间点上述指标和SvO₂、MAP、HR、CI、TSVR、ACC、LEVTi等血流动力学指标的变化趋势。 结果 单肺通气开始后动脉血氧分压PaO₂显著下降（从230mmHg下降到144mmHg），但在单肺通气过程中PaO₂保持在一个相对稳定的水平（141-148mmHg）。关胸后TLV使PaO₂显著升高（从148mmHg上升到278mmHg）。插管后TLV时的氧供和麻醉诱导前相比显著下降(从480ml·min^-1·m^-2下降到413ml·min^-1·m^-2)，氧耗明显下降(从97ml·min^-1·m^-2下降到64ml·min^-1·m^-2)。OLV过程中与插管后TLV相比，氧供维持在一个相对恒定的水平(404-421ml·min^-1·m^-2)，随着单肺通气时间的延长，氧耗逐渐增加(从78ml·min^-1·m^-2上升到89ml·min^-1·m^-2)；同时摄氧率逐渐增加（从18％上升到24％），动脉血乳酸浓度呈上升趋势(1.63～1.70mmol·L^-1)。关胸后TLV与OLV过程相比，氧供明显提高(从404ml·min^-1·m^-2上升到457ml·min^-1·m^-2)而氧耗维持在一恒定水平(91ml·min勇叹珍^笋矛漪九节氛汾功柑及益葫动力笋影嗬必瑙诉比劝泞谐戈摄氧率有所下降（从24%下降到22%），同时动脉血乳酸浓度也下降。麻醉诱导后，机体的心肌收缩力显著下降;到关胸时机体的心肌收缩力比麻醉诱导时显著上升。开胸后心率显著升高，关胸后心率恢复正常。围术期机体的MAP保持相对恒定。单肺通气过程中，碱剩余的负值逐渐增大。 结论 在目前常规的胸外科手术麻醉条件下（50%笑气复合静脉异丙酚维持麻醉）开胸手术期间，机体的氧供和氧耗处于平衡状态。机体的血流动力学也处于平衡状态。更多还原

【Abstract】 The reverse Fick method was used to evaluate the characteristic of oxygen metabolism during thoracic surgical procedures, and examine the changes of oxygen supply and oxygen consumption balance during one-lung ventilation. Transesophageal Doppler echocardiograph (HemosonicTM 100) was used to evaluate the changes of hemodynamics during the perioperative period.Methods30 patients(18 male, 12 female) aged(41 ± 12 yr),undergoing pneumonectomy were studied. The patients were premedicated with pethidine 50mg promethazine 25mg and atropine 0. 5mg im 30 min before operation. Anesthesia was induced with fentanyl 2ug kg-1 , midazolam 0.1-0. 2mg kg-1, vecuronium 0.12-0.15mg kg-1, propofol 1. 5-2. 5 mg kg-1 and maintained with inhalation of 50% nitrous oxide in oxygen and TCI propofol and intermittent iv boluses of fentanyl and vecuronium. Radial artery was cannulated, central venous pressure catheter was placed via internal jugular vein. Arterial blood gas analasis and mixed venous blood gas analasis were respectively done from the sober state to closure of the pleura cavity. Hemodynamic parameters including mean arterial pressure(MAP) heart rate(HR) cardiac output index(CI) stroke volume(SV) total systemic vascular resistance for aortic circuit(TSVR) HR-corrected left ventricular ejection time (LVETi) and peak aortic flow acceleration (ACC) were measured and recorded. Oxygen delivery (DO2) oxygen consumption(VO2) oxygen extraction rate(ERO2) mixed venousoxygen saturation(SvO2) arterial oxygen partial pressure(PaO2) and arterial blood lactate(ABL) were monitored during anesthesia.ResultsDuring OLV, PaO2 was decreased significantly(P < 0. 05). After the induction of anesthesia, oxygen delivery was decreased significantly compared with that of the sober state. During OLV, VO2 and ERO2 were increased gradually, while D02 was kept at a certain level(404-421 ml min-1 m-2).After pleural cavity closure, DO2 was increased significantly (from 404 to 457 ml min-1 m-2)and VO2 was kept at a certain level (91 ml min-1 m -2). After the induction of anesthesia, the myocardial contractility decreased significantly. When the pleura cavity was closed, the myocardial contractility returned to the baseline. During the one-lung ventilation, the base excess decreased gradually.ConclusionsAmong patients undergoing pneumonectomy during one-lung ventilation, oxygen supply demand balance was kept and tissue hypoxia did not occur. During the thoracotomy period, the hemodynamic parameters including CI SV, MAP and LVETi were kept at a balance state.更多还原