Effect of PEEP, blood volume, and inspiratory hold maneuvers on venous return
Effect of PEEP, blood volume, and inspiratory hold maneuvers on venous return
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DOI：
10.1152/ajpheart.00931.2015
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发表时间：
2016-09-01
影响因子：
4.8
通讯作者：
Takala, Jukka
中科院分区：
文献类型：
--
作者：
Berger, David;Moller, Per W.;Takala, Jukka
根据盖顿的循环模型，平均体循环充盈压（MSFP）、右心房压（RAP）和静脉回流阻力（RVR）决定静脉回流。MSFP已从吸气保持引起的RAP和血流变化中估计。本文研究了呼气末正压（PEEP）和血容量对猪静脉回流和最大血流速度（MSFP）的影响。MSFP通过右心房球囊闭塞（MSFPRAO）测量，MSFP通过气道闭塞（MSFPinsp_（hold））的压力-流量关系外推获得，MSFP通过在PEEP 5和10 cmH 2 O吸气保持期间、出血后和高血容量时RAP/肺动脉流量（Q（PA））关系外推获得。MSFPRAO随PEEP增加[PEEP 5，12.9（SD 2.5）mmHg; PEEP 10，14.0（SD 2.6）mmHg，P = 0.002]，而Q（PA）无变化[2.75（SD 0.43）vs. 2.56（SD 0.45）l/min，P = 0.094]。MSFPRAO在出血后降低，在高血容量时升高[分别为10.8（SD 2.2）和16.4（SD 3.0）mmHg，P < 0.001]，Q（PA）也有平行变化。PEEP和容量状态均未改变RVR（P = 0.489）。MSFPinsp_（hold）高估了MSFPRAO [16.5（SD 5.8）vs. 13.6（SD 3.2）mmHg，P = 0.001;平均差异3.0（SD 5.1）mmHg]。在正常血容量中，吸气暂停改变了RAP/Q（PA）关系，因为下腔静脉流量（Q（IVC））在吸气暂停最低点后早期恢复。出血后Q（IVC）最低点[在15 cmH（2）O吸气压力下，吸气前保持36%（SD 24%）]，并且Q（IVC）恢复在最低吸气压力下最完全，与容量状态无关[范围从出血后的80%（SD 7%）到吸气前Q（IVC）PEEP 10 cmH（2）O时的103%（SD 8%）]。因此，Q（IVC）恢复可能通过肝血管瀑布来保护静脉回流。
According to Guyton's model of circulation, mean systemic filling pressure (MSFP), right atrial pressure (RAP), and resistance to venous return (RVR) determine venous return. MSFP has been estimated from inspiratory hold-induced changes in RAP and blood flow. We studied the effect of positive end-expiratory pressure (PEEP) and blood volume on venous return and MSFP in pigs. MSFP was measured by balloon occlusion of the right atrium (MSFPRAO), and the MSFP obtained via extrapolation of pressure-flow relationships with airway occlusion (MSFPinsp_(hold)) was extrapolated from RAP/pulmonary artery flow (Q(PA)) relationships during inspiratory holds at PEEP 5 and 10 cmH(2)O, after bleeding, and in hypervolemia. MSFPRAO increased with PEEP [PEEP 5, 12.9 (SD 2.5) mmHg; PEEP 10, 14.0 (SD 2.6) mmHg, P = 0.002] without change in Q(PA) [2.75 (SD 0.43) vs. 2.56 (SD 0.45) l/min, P = 0.094]. MSFPRAO decreased after bleeding and increased in hypervolemia [10.8 (SD 2.2) and 16.4 (SD 3.0) mmHg, respectively, P < 0.001], with parallel changes in Q(PA). Neither PEEP nor volume state altered RVR (P = 0.489). MSFPinsp_(hold) overestimated MSFPRAO [16.5 (SD 5.8) vs. 13.6 (SD 3.2) mmHg, P = 0.001; mean difference 3.0 (SD 5.1) mmHg]. Inspiratory holds shifted the RAP/Q(PA) relationship rightward in euvolemia because inferior vena cava flow (Q(IVC)) recovered early after an inspiratory hold nadir. The Q(IVC) nadir was lowest after bleeding [36% (SD 24%) of preinspiratory hold at 15 cmH(2)O inspiratory pressure], and the Q(IVC) recovery was most complete at the lowest inspiratory pressures independent of volume state [range from 80% (SD 7%) after bleeding to 103% (SD 8%) at PEEP 10 cmH(2)O of Q(IVC) before inspiratory hold]. The Q(IVC) recovery thus defends venous return, possibly via hepatosplanchnic vascular waterfall.