RESPIRATORY FUNCTION OPTIMIZATION WITH HIGH FREQ VENTIL

通常认为潮汐低潮的高频呼吸(HFV) 体积(小于解剖死腔)可产生较低的肺泡。 压力高于传统机械通风，从而减少了 随之而来的是气压伤和心输出量减少的风险。但是，在一个 初步的建模研究，我们发现这一假设并不总是 有效。我们建议在狗身上做一系列实验来检验这个模型。 预测和加深我们对气体之间相互作用的理解 肾综合征出血热期间的转运和肺力学。我们将确定最优的 HFV参数组合，可同时最大化气体 交换和最小化肺泡压力。有问题的参数包括 频率、潮气量、气流波形和肺容量。我们会 调查在某些情况下对呼吸优化有何影响 模拟疾病条件。我们还将比较应用的效果 胸外摆动是HFV较为常见的模式 通过气管进行敷贴。从我们对气体运输的测量来看，当地 呼吸道运输阻力和肺部机械特性，我们将 开发一个包含气体交换和气体交换的数学模型 HFV的肺力学方面，包括重要的非线性，如 气体捕捉器。这个模型将被用来产生具有临床意义的 预测人类如何最好地优化呼吸功能 患有肺部疾病的成年人和婴儿。

It is often presumed that high frequency ventilation (HFV) with low tidal volumes (smaller than anatomic dead space) produces lower alveolar pressures than conventional mechanical ventilation, thus reducing the attendant risks of barotrauma and diminished cardiac output. However, in a preliminary modeling study, we found that this presumption is not always valid. We propose a series of experiments on dogs to test the model prediction and to further our understanding of the interaction between gas transport and lung mechanics during HFV. We will determine the optimal combination of HFV parameters that would simultaneously maximize gas exchange and minimize alveolar pressures. The parameters in question are frequency, tidal volume, airflow waveform and lung volume. We will investigate how respiratory optimization is affected under certain simulated disease conditions. We will also compare the effects of applying HFV by external chest oscillation with the more common mode of HFV application via the trachea. From our measurements of gas transport, local airway transport resistances and lung mechanical characteristics, we will develop a mathematical model that incorporates both the gas exchange and lung mechanics aspects of HFV, including important nonlinearities such as gas trapping. This model will be used to generate clinically significant predictions of how respiratory function may best be optimized in human adults and infants with pulmonary disease.