Figure 1.

Theoretical schematic illustration of dynamic pressure-volume curves (thin lines) for conventional mechanical ventilation (CMV) and apneustic anesthesia ventilation (AAV) superimposed on individual pressure-volume curves (bold lines) for the respiratory system. AAV was designed to preserve lung architecture and compliance in the anesthetized human by periodically releasing airway pressure from a high to low level while maintaining lung volume at or above functional residual capacity (FRC). By contrast, CMV ventilates the lung from below FRC leading to the development of atelectasis, shifting of the pressure-volume curve to the right and lower compliance. In this scenario, higher pressures are required during CMV to achieve the same tidal volume. Reproduced with permission from Innovative Veterinary Medicine.