How the ventilator works

Respiratory support is one of the most critical means of saving the lives of emergency and critically ill patients. Therefore, the ventilator has become an indispensable device in clinical treatment; it is increasingly used in the fields of emergency, anesthesia, ICU and respiratory therapy; master The basic knowledge and basic operation methods of the ventilator are the basic knowledge and skills necessary for clinicians. This article briefly summarizes some common knowledge of ventilator in clinical application:

The basic principle of the ventilator: Inspiratory action during autonomous ventilation generates negative chest pressure, passive expansion of the lungs causes alveolar and negative airway pressure, which constitutes the pressure difference between the airway mouth and the alveoli to complete the inhalation; after inhalation, the chest and lungs Elastically retracts, producing the opposite pressure difference to complete exhalation. Therefore, normal breathing is caused by the body’s “active negative pressure difference” between the alveoli and the airway opening through breathing. The inhalation of the thorax and lung elasticity after inhalation produces a passive positive pressure difference between the alveolar and airway opening and exhales. To meet the needs of physiological ventilation. The ventilator ventilation is driven by an external mechanical drive to generate a positive pressure difference between the airway opening and the alveoli, and the exhalation is a passive positive pressure difference between the alveolar and the airway opening caused by the chest and lung elastic retraction after the external mechanical driving pressure is removed. That is, there are “passive positive pressure differences” in the breathing cycle to complete the breathing.