脊柱手术中体位变化对全麻高浓度氧通气效果的影响

Impacts of position changes on high concentration oxygen ventilation in spinal surgery under general anesthesia

目的分析脊柱手术过程中体位变化影响全麻高浓度氧通气的效果。方法选择腰椎后路手术的82例ASA I^II级患者均接受全麻,在以100%氧浓度麻醉诱导后以80%氧浓度行机械通气时间15 min(Ta)、体位从仰卧位变成俯卧位时间15 min(Tb)、俯卧位后1 h(Tc)、俯卧位变成仰卧位前(Td)、翻身变成仰卧位后15 min(Te)分别监测,然后算出肺泡动脉氧含量差、氧合指数。结果 Tb^Te各时间点的肺泡气与动脉血氧分压差明显小于Ta时间点,差异有统计学意义(P<0.05)。患者处于俯卧位状态下(Tb-Td)时间点时,平均气道压与仰卧位(Ta、Te)比较明显增高,但顺应性明显下降,差异有统计学意义(P<0.05)。结论在正确体位状态下行脊柱手术期间,俯卧位能提高患者氧合效果。

Objective To study the impacts of position changes on high concentration oxygen ventilation in spinal surgery under general anesthesia. Methods A total of 82 ASA I-II patients for lumbar posterior surgery under general anesthesia were enrolled for study. At the time points of 15 mins after anesthesia induction （Ta）, 15 mins after position change from supine to prone （Tb）, 1 hour after the prone position （Tc）,at the end of prone position （Td） and 15 mins after the supine position （Te） arterial blood gas,at the same time, alveolar artery oxygen content and oxygenation indexs were calculated. Results From time point of Tb to Te,alveolar air and arterial blood oxygen partial pressure difference were much smaller than that of Ta, the differences were statistically significant. Mean airway pressure were significantly increased while the pulmonary compliance decreased obviously at the time points of Ta and Te when compared with those at time points of Tb,Tc and Td. Conclusion Under high concentration oxygen ventilation,prone position during spinal surgery can not only increase airway pressure,but also reduce pulmonary compliance and improve patients ventilation and oxygenation.