Ventilator modes: old and new.

CPPV is an accepted standard of treatment in patients with acute respiratory failure. Because of rapid technologic advancements, new modes of ventilation have been developed. Unfortunately, this occurs at a time when there are still many controversies about the relative benefits and modes of action of CPPV. Before the proliferation of use of these newer modes in the intensive care units, documentation of the beneficial effects and safety of these modalities under controlled condition is of utmost importance. Although some of the "new" ventilatory modes (PSV, PAV) improve patient comfort and synchrony, and PAV has the potential to replace CPPV, the superiority of the "new" ventilatory modes over that of CPPV remains to be established, particularly in the area of patient survival, morbidity, and cost.