Effects of positive end-expiratory pressure ventilation on cerebral venous pressure with head elevation in dogs.
Effects of positive end-expiratory pressure ventilation on cerebral venous pressure with head elevation in dogs.
复制标题
呼气末正压通气对狗头部抬高时脑静脉压的影响。
DOI：
10.1152/jappl.2000.88.2.655
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Traystman,RJ
中科院分区：
文献类型：
--
作者：
Toung,TJ;Aizawa,H;Traystman,RJ
呼气末正压（PEEP）机械通气可预防坐位时静脉空气栓塞，因为PEEP可引起右心房压（Pra）升高，从而导致脑静脉压（Pcev）升高。虽然很明显，当犬处于俯卧位时，PEEP诱导的Pra增加到Pcev存在线性传递，但犬处于抬头位时的传递机制尚不清楚。我们测试的假设，一个八哥阻力型机制存在于颈静脉时，头部抬高。在一组狗中，增加PEEP线性增加Pcev与狗在俯卧位（头部在心脏水平，斜率= 0.851），但不增加Pcev时，头部抬高。在另一组狗中，使用外部胸部捆绑器来产生更大的PEEP诱导的Pra增加。进一步增加Pra仅在Pra超过19 mmHg的压力（破裂压力）后才增加Pcev。上游（Pcev）-下游（Pra）关系的这种急剧拐点表明，这可能是由Starling电阻型机制引起的。我们的结论是颈静脉塌陷作为一个显着的阻力Pra传输到Pcev在头部抬高的位置。
Mechanical ventilation with positive end-expiratory pressure (PEEP) may prevent venous air embolism in the sitting position because cerebral venous pressure (Pcev) could be increased by the PEEP-induced increase in right atrial pressure (Pra). Whereas it is clear that there is a linear transmission of the PEEP-induced increase in Pra to Pcev while the dog is in the prone position, the mechanism of the transmission with the dog in the head-elevated position is unclear. We tested the hypothesis that a Starling resistor-type mechanism exists in the jugular veins when the head is elevated. In one group of dogs, increasing PEEP linearly increased Pcev with the dog in the prone position (head at heart level, slope = 0.851) but did not increase Pcev when the head was elevated. In another group of dogs, an external chest binder was used to produce a larger PEEP-induced increase in Pra. Further increasing Pra increased Pcev only after Pra exceeded a pressure of 19 mmHg (break pressure). This sharp inflection in the upstream (Pcev)-downstream (Pra) relationship suggests that this may be caused by a Starling resistor-type mechanism. We conclude that jugular venous collapse serves as a significant resistance in the transmission of Pra to Pcev in the head-elevated position.