CONSEQUENCES OF PEEP AND HIGH FREQUENCY VENTILATION

这些研究是为了确定不同程度的积极影响， 呼气末压力（PEEP）和高频通气（HFV） 肺经血管液体交换在正常和高通透性 肺。 研究将在完整的，麻醉的绵羊中进行， 可以收集纯肺淋巴液。 淋巴流量的测定 淋巴和血浆蛋白浓度及湿肺与无血肺干肺比值 将用于评估液体过滤和血管 由于PEEP或HFV的作用， 正常肺和血管损伤肺。 此外，总体和区域 肺血流与标记的微球将进行研究下， 不同的实验条件和不同的通风模式。 这些 研究将与测量和间质压相关 根据帕克等人的方法， PEEP和HFV可能影响的机制的基础 肺经血管液体平衡 HFV是一种临床上非常有前途的 一种新的通风模式，可广泛应用于密集型 护理设置。 由于其生理基础尚不清楚，肺 正常和高渗透性下的血液动力学和整体气体交换 将使用大视野闪烁进行犬肺检查 照相机和标记的微球。 通过HFV实验，平均气道 压力将保持在最低水平（203 cm H2O），因为这是 HFV超过PEEP通气。

These studies are to determine the effects of varying levels of positive end-expiratory pressure (PEEP) and high frequency ventilation (HFV) on pulmonary transvascular fluid exchange in the normal and high permeability lung. Studies will be made in the intact, anesthetized sheep in which it is possible to collect pure lung lymph. Determination of lymph flow of lymph and plasma protein concentration and wet-to-bloodless dry lung ration will be used to assess possible changes in fluid filtration and vascular permeability as they may or may not occur as a result of PEEP or HFV in the normal and vascular injured lung. In addition, the overall and regional pulmonary blood flow with labelled microspheres will be studied under the various experimental conditions and different modes of ventilation. These studies will be correlated with measurement and interstitial pressure according to the method of Parker et al. and may provide physiological bases for the mechanism by which PEEP and HFV may have their effects on pulmonary transvascular fluid balance. HFV is a clinically very promising new mode of ventilation that may find wide application in the intensive care setting. Since its physiological base is not known, pulmonary hemodynamics and overall gas exchange in the normal and high permeability lung of the dog will be performed utilizing a large field scintillation camera and labelled microspheres. With the HFV experiments the mean airway pressure will be kept minimal (203 cm H2O), as this is a major advantage of HFV over PEEP ventilation.