Mosing Martina, Kutter Annette P N, Iff Samuel, Raszplewicz Joanna, Mauch Jacqueline, Bohm Stephan H, Tusman Gerardo
Division of Anaesthesiology, Equine Department, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland,
J Clin Monit Comput. 2015 Feb;29(1):187-96. doi: 10.1007/s10877-014-9588-0. Epub 2014 Jun 8.
The aim of this study was to test the effect of cardiac output (CO) and pulmonary artery hypertension (PHT) on volumetric capnography (VCap) derived-variables. Nine pigs were mechanically ventilated using fixed ventilatory settings. Two steps of PHT were induced by IV infusion of a thromboxane analogue: PHT25 [mean pulmonary arterial pressure (MPAP) of 25 mmHg] and PHT40 (MPAP of 40 mmHg). CO was increased by 50% from baseline (COup) with an infusion of dobutamine≥5 μg kg(-1) min(-1) and decreased by 40% from baseline (COdown) infusing sodium nitroglycerine≥30 μg kg(-1) min(-1) plus esmolol 500 μg kg(-1) min(-1). Another state of PHT and COdown was induced by severe hypoxemia (FiO2 0.07). Invasive hemodynamic data and VCap were recorded and compared before and after each step using a mixed random effects model. Compared to baseline, the normalized slope of phase III (SnIII) increased by 32% in PHT25 and by 22% in PHT40. SnIII decreased non-significantly by 4% with COdown. A combination of PHT and COdown associated with severe hypoxemia increased SnIII by 28% compared to baseline. The elimination of CO2 per breath decreased by 7% in PHT40 and by 12% in COdown but increased only slightly with COup. Dead space variables did not change significantly along the protocol. At constant ventilation and body metabolism, pulmonary artery hypertension and decreases in CO had the biggest effects on the SnIII of the volumetric capnogram and on the elimination of CO2.
本研究旨在测试心输出量（CO）和肺动脉高压（PHT）对容积式二氧化碳描记法（VCap）衍生变量的影响。使用固定通气设置对9头猪进行机械通气。通过静脉输注血栓素类似物诱导两个阶段的PHT：PHT25 [平均肺动脉压（MPAP）为25 mmHg]和PHT40（MPAP为40 mmHg）。通过输注多巴酚丁胺≥5 μg·kg⁻¹·min⁻¹使CO较基线增加50%（COup），通过输注硝酸钠≥30 μg·kg⁻¹·min⁻¹加艾司洛尔500 μg·kg⁻¹·min⁻¹使CO较基线降低40%（COdown）。严重低氧血症（FiO₂ 0.07）诱导出另一种PHT和COdown状态。使用混合随机效应模型记录并比较每个阶段前后的有创血流动力学数据和VCap。与基线相比，PHT25时III期归一化斜率（SnIII）增加32%，PHT40时增加22%。COdown时SnIII非显著降低4%。与严重低氧血症相关的PHT和COdown组合使SnIII较基线增加28%。PHT40时每呼吸二氧化碳清除率降低7%，COdown时降低12%，但COup时仅略有增加。死腔变量在整个实验过程中无显著变化。在通气和身体代谢恒定的情况下，肺动脉高压和CO降低对容积式二氧化碳图的SnIII和二氧化碳清除影响最大。
