What is the function of the ventilator's end-expiratory occlusion test?

The end-expiratory occlusion test is a valuable technique primarily used to measure the static compliance of the respiratory system. This test is conducted by temporarily occluding the ventilatory circuit at the end of expiration, allowing for the assessment of the pressure in the respiratory system during a stable phase of the breathing cycle.

When the occlusion occurs, any change in lung volume can be observed relative to the applied pressure, allowing clinicians to determine the compliance characteristics of both the lung and the chest wall. Static compliance is defined as the change in volume of the lungs per unit change in pressure, and it gives insight into the elastic properties of the lung tissue and the thoracic cavity.

By measuring static compliance, healthcare providers can gauge the effectiveness of the ventilator settings as well as the patient's underlying lung mechanics, which is critical in managing various respiratory conditions. This makes the end-expiratory occlusion test an essential tool in the monitoring and adjustment of ventilatory support.