过度通气时不同潮气量对颅脑手术病人脑氧代谢的影响

Effect of Various Degrees of Tidal Volume on The Cerebral O_2 Metabolism in Patients with Craniocerebral Operations When They Were Hyperventilated

为颅脑手术病人寻求过渡通气时较为理想的潮气量，采用不同潮气量（12mL／kg、10mL／kg、8mL／kg）对三组颅脑手术病人实行过度通气，观察其对颅脑手术病人脑氧代谢的影响。结果显示：Ⅰ组动脉血二氧化碳分压（PaCO2）、颈内静脉氧分压（PjvO2）和颈内静脉二氧化碳分压（PjvCO2）较基础值和Ⅱ、Ⅲ二组对应值低（P〈0．01）；通气60min后Ⅰ组颈内静脉血氧饱和度（SjvO2）、颈内静脉血氧含量（CjvO2）降低，而脑氧摄取（CEO2）增高，与其基础值及Ⅱ、Ⅲ组的对应值相比较，差异有统计学意义（P〈0．05）；重度过度通气的Ⅰ组，有40％（4／10）的病人其SjvO2〈50％。结论：维持潮气量为8-10mL／kg，是颅脑手术病人较为理想的过度通气。

To find a better hyperventilation for patients with craniocerebral operations. Method Three groups of patients undergoing craniocerebral operations were hyperventilated with different tidal volume（ 12mL/kg, 10mL/kg, 8mL/kg）, to observe the effect of various degrees of tidal volume on the cerebral O2 metabolism in patients with craniocerebral operations. It is demonstrated that the PaCO2, PjvO2 and PjvCO2 in group Ⅰ were lower than the baselines and that of group Ⅱ and group Ⅲ（ P 〈 0.01 ）. After 60 minutes of ventilation, the SjvO2 and CjvO2 decreased, and CEO2 increased in group Ⅰ, which were statistically significant compared with the baselines and that of group Ⅱ and group Ⅲ（ P 〈 0.05）. In group I, the SjvO2 of 40% patients is less than 50%. It is concluded that deep hyperventilation（the tidal volume at 12mL/kg） leads to disorders of cerebral O2 metabolism and the tidal volume at 8 - 10mL/kg is the better hyperventilation for patients with eraniocerebral operations.