One of the problems is that these type of ventilators do not maintain a constant air pressure, this causing the alveoli to collapse. This breaks down the alveoli cell wall and increases the fluid blocking O2 transfer.
A CPAP, or constant pressure device maintains the pressure and functions on a differential wave to provide respiration. This constant pressure stops the alveoli from collapsing on zero or negative pressure.
This is also why the probe position decreased the death rate by approximately 16%.
A modified CPAP would work far better.