As a technical advancement of pressure-controlled ventilation in an open system, dynamic BiLevel combines the known benefits of the BiLevel mode with the advantage of constant-volume ventilation. The upper pressure level adjusts to the changes in compliance and resistance, which permits an almost volume-constant ventilation. Instead of setting two different pressure levels, users only choose the desired tidal volume. After a test stroke of the ventilator, the upper pressure level adjusts automatically based on the mechanical breathing parameters, which leads to reaching the selected tidal volume. At the same time, the user sets a control range, in which the system can self-adjust automatically. The upper limit of the control range is established with the "Plimit" setting, while the "PASB" setting represents the lower pressure limit. The system will then automatically adjust the pressure as necessary within this control range, using steps of max. 3 mbar from one ventilation stroke to another.
Dynamic BiLevel not only combines the advantages of volume-controlled and pressure-controlled ventilation, but also significantly reduces operator involvement.