小潮气量联合低水平呼吸末正压通气对丙泊酚麻醉下老年腹腔镜胃癌根治术患者术后认知功能的影响

Effects of low tidal volume combined with low level positive pressure at expiratory end on cognitive function of elderly patients received laparoscopic radical gastric resection in propofol anesthesia

目的评价小潮气量联合低水平呼气末正压通气对丙泊酚麻醉下老年腹腔镜胃癌根治术患者术后认知功能的影响。方法择期全身麻醉下腹腔镜胃癌根治术老年患者80例,年龄65~80岁,美国麻醉师学会（ASA）分级I、Ⅱ级,采用随机数字表法,将患者随机分为两组（n=40）：常规通气组（A组）和小潮气量低水平呼气末正压通气组（B组）。A组通气参数：VT,9 ml/kg,RR 12次/min,吸呼比1∶2。B组通气参数：VT 6 ml/kg,RR 16次/min,吸呼比l∶2,呼气末正压（PEEP）5 cm H2O。于气腹前（T0）、气腹后1 h（T1）、气腹后2 h（T2）、气腹后3 h（T3）时经桡动脉、颈内静脉球部采集血样行血气分析,计算动脉-颈内静脉血氧含量差（Da-jv O）2和脑氧摄取率（CERO2）,术中气道峰压（Ppeak）,动脉血二氧化碳分压（Pa CO）及血流动力学参数平均动脉2压（MAP）,中心静脉压（CVP）。于术前1 d、术后1 d、术后1周时采用简易智能状态检查表（MMSE）评分评价术后认知功能。结果与A组相比,B组T1~T3时Da-jv O2和CERO2降低,各时点Ppeak、Pa CO2、MAP、CVP组间比较差异无显著性,术后MMSE评分升高,术后认知功能障碍发生率降低（P〈0.05）。结论小潮气量联合低水平呼吸末正压通气可改善丙泊酚麻醉下行腹腔镜胃癌根治术老年患者的脑氧代谢,减轻术后认知功能障碍。

【Objective】To evaluate effect of low tidal volume combined with low level of positive pressure at expiratory end on the cognitive function received laparoscopic radical gastric resection in propofol anesthesia.【Methods】80 cases of elderly patients with gastric cancer were elected by laparoscopic radical gastrectomy under general anesthesia in a period time, aged 65 to 80 years old, ASA grade I or grade II. Using the random number table, the patients were randomly divided into 2 groups（n =40）： they were conventional ventilation group（A group）and low tidal volume and positive pressure expiratory end ventilation group（B group）. A group of ventilation parameters were VT, 9 ml/kg, 12 RR /min, breath rate： 1∶2, B group of ventilation parameters were VT 6 ml/ kg, 16 RR /min, breath rate： 1∶2, positive end expiratory pressure（PEEP） was 5 cm H2 O. Their blood samples were collected and blood gas was analyzed by radial artery and jugular venous bulb before pneumoperitoneum（T0）, one hour after pneumoperitoneum（T1）, two hours after pneumoperitoneum（T2）, three hours after pneumoperitoneum（T3）, they were calculated arterial jugular venous oxygen content difference（Da-jv O2）, cerebral oxygen extraction rate（CERO2）, intraoperative peak airway pressure（Ppeak）, arterial partial pressure of carbon dioxide（Pa CO2） and mean arterial pressure（MAP） and hemodynamic parameters, central venous pressure（CVP）. Cognitive function was accessed with the mini mental state examination（MMSE） score on one day before operation, one day postoperative, and one week after operation. 【Results】Compared with A group B group was decreased at each time point, T1-T3 Da-jv O2 and CERO2Ppeak, Pa CO2, MAP, CVP was not significant statistically difference between the two groups, MMSE scores were increased in postoperative, incidence of cognitive dysfunction were decreased（P 0.05） in postoperative.【Conclusion】Cerebral oxygen metabolism was better with low tidal volume combined with low level of positive pressure expiratory end in laparoscopic radical gastrectomy for gastric cancer in elderly patients during the propofol anesthesia, and reduced effect of cognitive function after operative.