Modes of pressure delivery and patient-ventilator interaction.

Differences between assist-control pressure and volume ventilation are minimal provided that peak inspiratory flow delivered at early inspiration matches patient demand Ventilation at constant flow and controlled tidal volume allow instantaneous analysis of the patient-ventilator interactions and the mechanical properties of the respiratory system. The cycle-per-cycle variability of peak inspiratory flow, which is permitted in pressure-limited modes, may allow better patient comfort. We do not know if one mode (pressure controlled or volume controlled) is superior to the other in terms of outcomes.