病态肥胖患者腔镜胃旁路手术麻醉中Pet-CO_2和PaCO_2的相关性

Correlation between Pet-CO_2 and PaCO_2 in morbidly obese patients during anesthesia for laparoscopic gastric bypass surgery

目的观察病态肥胖患者腔镜胃旁路手术麻醉中动脉血二氧化碳分压（PaCO2）与呼吸末二氧化碳分压（Pet-CO2）的关系。方法观察40例BMI为35～50kg／m^2，在腔镜下行胃旁路手术的病态肥胖患者，记录在全麻插管后气腹前、气腹30min，气腹60min，气腹120min，放气后30min，放气后60min等不同时间点PaCO2和Pet-CO2的值，比较PaCO2和Pet-CO2的值及其相关性。结果各时间点的Pet-CO2值均低于PaCO2值，在气腹前、气腹时和气腹放气后3种不同的机体状态下PaCO2和Pet-CO2呈密切正相关（P〈0．05），在16mmHg中等压力CO：气腹状态下，气腹后30、60、120min3个时间点PaCO2和Pet-CO2的相关性与气腹前、气腹放气后PaCO2和Pet-CO2的相关性的r值有差别。

Objective To investigate the correlation between arterial partial pressure of CO2 （PaCO2） and end expiratory tidal partial pressure of CO2 （Pet-CO2） in morbidly obese patients during anesthesia for laparoscopic gastric bypass surgery. Methods Forty morbidly obese patients with a body mass index （BMI） between 35 and 50 kg/m2 underwent laparoscopic gastric bypass surgery under general anesthesia. PaCO2 and Pet-CO2 were measured after intubation and before induction of pneumoperitoneum （To）, at 30 min （T1）, 60 min （T2）, and 120 rain （TO） during pneumoperitoneum, and at 30 min （TO） and 60 rain （TO） after deflation. Results At each time point of measurement, Pet-CO2 was lower than PaCO2 in all the patients. PaCO2 and Pet-COs were positively correlated before, during, and after pneumoperitoneum （P〈0.05）. At a moderate pressure of CO2 pneumoperitoneum （16 mmHg）, the level of correlation between PaCO2 and Pet-CO2 at T1, T2, and TO differed from that before and after post-pneumoperitoneum. Conclusion PaCO2 and Pet-COs are closely correlated during a moderate COs pneumoperitoneum in morbidly obese patients undergoing laparoscopic gastric bypass surgery.