You have no idea what you are talking about...in regard to ventilators....I actually do....
No idea about your comment..about drugs and knives...
Note: COVID-19 patients have damaged lungs.
It is generally regarded, based on animal models and human studies, that volutrauma is the most harmful aspect of mechanical ventilation.[2][3][4] This may be regarded as the over-stretching of the airways and alveoli.
During mechanical ventilation, the flow of gas into the lung will take the path of least resistance. Areas of the lung that are collapsed (atelectasis) or filled with secretions will be underinflated, while those areas that are relatively normal will be overinflated. These areas will become overdistended and injured. This may be reduced by using smaller tidal volumes.[5][6]
During positive pressure ventilation, atelectatic regions will inflate, however, the alveoli will be unstable and will collapse during the expiratory phase of the breath (atelectotrauma). This repeated alveolar collapse and expansion (RACE) is thought to cause VALI. By opening the lung and keeping the lung open RACE (and VALI) is reduced.[7]
Another possible ventilator-associated lung injury is known as biotrauma. Biotrauma involves the lung suffering injury from any mediators of the inflammatory response or from bacteremia.
Finally oxygen toxicity contributes to ventilator-associated lung injury through several mechanisms including oxidative stress.
Possible reasons for predisposition to VALI include:
An injured lung may be at risk for further injury
Cyclic atelectasis is particularly common in an injured lung