气管内吸引术对颅内高压动物的影响研究

Effect of endotracheal suctioning in animals with intracranial hypertention

目的观察开放式气管内吸引术(Open endotracheal suctioning,Open ETS)与闭合式气管内吸引术(Closed endotracheal suctioning,Closed ETS)对颅内高压动物颅内压(ICP)和脑氧代谢等方面的影响及其意义。方法实验动物随机分成OpenETS组(n=10)和ClosedETS组(n=10),分别进行两种气管内吸引术。于吸引前、后动态监测ICP,血气分析观察颈静脉氧饱和度(SjvO2)、脑氧摄取率(CEO2)和脑动静脉氧差(AVDO2)变化。结果两组动物吸引后即时ICP均短暂升高,两组变化趋势基本相同,大多于5min内回落,其回复较SjvO2快。吸引后即时OpenETS组SjvO2下降至(75.8±5.5)(%P<0.01),CEO2,AVDO2明显上升(P<0.01),而Closed ETS组SjvO2上升(P<0.05),CEO2、AVDO2下降(P<0.05)。结论颅内高压状态下OpenETS可引起脑缺血、缺氧反应,而Closed ETS不损害脑灌注(CPP)并维持足够脑氧供。建议颅脑外伤后可尝试运用ClosedETS。

[objective] To study the effect and significance of open endotracheal suctioning and closed endotracheal suctioning on ICP and cerebral oxygenation in animals with intracranial hypertention. [Methods] The intubated and mechanically ventilated animals were randomly assigned to open ETS group （n=10） and closed ETS group （n=10）, Open ETS and closed ETS were applied respectively. By analyzing blood gases the changes in SjvO2, CEO2 and ,AVDO2 were observed, and ICP were continuously monitored before and after the procedures. [Results] All the animals had transient elevations of ICP immediately after ETS, and there was a same trend of ICP changing in two groups. In most cases, ICP had returned to baseline within 5 minutes, which was more rapidly than SjvO2 immediately after ETS, SjvO2 was greatly decreased to （75.8±5.5） % （P 〈0.01）, CEO2 and AVDO2 improved （P 〈0.01）, in open ETS group, while in closed ETS group SjvO2 increased （P 〈0.05）, and CEO2 and AVDO2 decreased （P 〈0.05）. [Conclusions] Open ETS can negatively influence cerebral oxygenation during intracranial hypertention, whereas closed ETS had no adverse effect on CPP and maintained cerebral oxygenation. Closed ETS should be recommended in traumatic brain-injured patients.