BCV for Asthma
If you have Asthma the inside walls of your airways can become inflamed. The inflammation makes the airways very sensitive, and they tend to react strongly to things that you are allergic to or find irritating. When the airways react, they get narrower, and less air flows through to your lung tissue. This causes symptoms like wheezing (a whistling sound when you breathe), coughing, chest tightness, and trouble breathing. During an asthma attack, muscles around the airways tighten up, making the airways narrower so less air flows through. Inflammation increases, and the airways become more swollen and even narrower Cells in the airways may also make more mucus than usual. This extra mucus also narrows the airways. These changes make it harder to breathe.
BCV works by recruitment of alveoli and improvement in ventilation/perfusion matching. Negative exrathoracic pressure of any sort provides a distending pressure on both airways and alveoli by increasing the transpulmonary pressure gradient. It may differ from positive airway pressure by avoiding compression of the pulmonary vascular bed. In an infant, it may also stabilize the easily collapsible chest wall, overcoming small airway closure and reducing air trapping. BCV will improve airway conductance or lung compliance. This is associated with a decrease WOB (work of breathing ) and makes the patient more comfortable.
BCV has been proven to increase muscle strength and endurance, decrease hypercapnia, improve functional reserve of the respiratory muscles and decrease inspiratory muscle fatigue.