LUNG VASCULAR EFFECTS OF HIGH FREQUENCY VENTILATION

本项目的目的是调查高浓度的 高频通气（HFV）对肺血管功能的影响。 的 工作假设是，血管活性物质，类花生酸和 心房利钠因子（ANF）是在物质可以 影响心输出量、肺和全身血管 压力和水平衡。 HFV的影响可能是 受通风条件的调节，包括 缺氧和高碳酸血症 最初，兔子是实验性的。 动物 它们是最低级的动物 我们获得有用的数据HFV系统。 在身体和 器官大小和重量，它们将接近人类婴儿。 随后的数据将在绵羊中收集， 模拟机械通风人体的条件。 HFV是 在麻醉期间，当外科医生 或者当他需要一个静止的场时。 HFV也很重要，因为血液中的CO2需要通过 最小压力成本，例如支气管胸膜瘘、肺 间质性肺气肿或持续性肺动脉高压， 新生儿 目前尚无关于HFV影响的研究报告 关于胜利阵线的释放 此外，迄今为止， HFV对类花生酸释放的影响，特别是 产生了相互矛盾的结果。 生理 本项目记录的参数包括系统和 肺动脉血压，肺楔压， 左心房压、心率、心输出量、动脉血 气体，包括pH值，类花生酸和ANF的浓度， 血浆和淋巴液中，气道压力和体温。 将通过热稀释法测定心输出量 法 心脏导管插入术也将提供测量 肺动脉压和肺楔压。 肺血管阻力将根据心脏 输出和肺动脉和楔形或左心房 压力 将HFV的效果与常规方法进行比较 机械通气对肺血管功能的影响。 我们将 检测HFV对缺氧性肺血管收缩的影响 以及内源性调节剂如ANF的释放。 我们将 研究急、慢性输注心钠素对肺的影响 血管和气道功能以及缺氧性血管收缩。

The objective of this project is to investigate the effects of high frequency ventilation (HFV) on pulmonary vascular function. The working hypothesis is that vasoactive substances, eicosanoids and atrial natriuretic factor (ANF) are released during substances can influence cardiac output, pulmonary and systemic vascular pressures and water balance. The effects of HFV may be modulated by the conditions of ventilation, including the presence of hypoxia and hypercapnia. Initially rabbits will be experimental animals. These are the lowest order of animals which will allow us to obtain useful data on the HFV system. In terms of body and organ sizes and weights, they will approximate human infants. Subsequent data will be collected in sheep to more closely simulate conditions in the mechanically ventilated human. HFV is clinically important during anesthesia when the surgeon is competing for the airway or when he requires a motionless field. HFV is also important where blood CO2 is to be removed with the least pressure cost such as with bronchopleural fistula, pulmonary interstitial emphysema or persistent pulmonary hypertension in the newborn. No studies have been reported on the effect of HFV on the release of ANF. Also, the very few studies reported so far on the effect of HFV on the release of eicosanoids, particularly during hypoxia, have yielded conflicting results. Physiological parameters to be recorded in this project include systemic and pulmonary arterial blood pressures, pulmonary wedge pressure, left atrial pressure, heart rate, cardiac output, arterial blood gases, including pH, concentrations of eicosanoids and ANF in plasma and in lymph, airway pressure and body temperature. Cardiac output will be determined by the thermodilution technique. Cardiac catherization will also provide a measurement of pulmonary arterial pressure and pulmonary wedge pressure. Pulmonary vascular resistance will be calculated from cardiac output and the pulmonary arterial and wedge or left atrial pressures. The effect of HFV will be compared with conventional mechanical ventilation on pulmonary vascular function. We will test the effects of HFV on hypoxic pulmonary vasoconstriction and on release of endogenous modulators such as ANF. We will study the effects of acute and chronic infusion of ANF on lung vascular and airway function and on hypoxic vasoconstriction.