VDR-IV Summary

The article primarily discusses the background of HFPV, its mechanisms and functions, the components of the VDR-4, as well as nursing care considerations for patients receiving HFPV. After providing a background on its clinical use and the basic operating principles behind this particular ventilation mode, the article paid significant attention on its components- the ventilation assembly, circuits, nebulizer, and ventilation monitoring unit- in order to fully comprehend how the ventilator increases oxygenation and ventilation.
The Phasitron, which serves as the ventilation valve assembly in the VDR-4, uses a high-pressure circuit to allow a spring-controlled venturi body to move back and forth in a percussive manner and provide laminar airflow
delivery at lower peak airway pressures. It utilizes the Bernoulli principle (air pressure at point A is higher than point B) and the Venturi theory (air speed at point A is lower than point B) where gas moves through the Phasitron at higher flow and at the lowest pressure resulting in equal pressure on both sides. The high laminar flow of gas on one end causes countercurrent gas flow from the opposite end resulting in a distal to proximal gas concentration gradient which allows effective oxygenation and ventilation (Kunugiyama and Schulman, 2012).