Covid-19: lung damage could be caused by the efforts some patients have to make to breathe

The lung damage observed in some patients with a severe form of Covid could be linked to the efforts they are forced to make to breathe. These lesions would therefore not only be the consequences of the mechanical ventilation implemented in the event of acute respiratory failure. That’s what advances a study by researchers at the University of Warwick published in the journal Annals of Intensive Care.

It was known that the use of ventilators could damage already diseased lungs and protocols have been put in place to limit the excessive pressures and forces produced by these devices. But a team of critical care clinicians have used computer modeling that suggests the breathing efforts made by patients themselves can also produce pressures and strains inside the lungs that can cause damage.

Efforts that need to be monitored

To reach this conclusion, the scientists set up a simulator representing a population of 10 Covid patients treated with supplemental oxygen. Several respiratory rates were tested ranging from normal breathing to high respiratory effort: the results indicated that potentially detrimental pressures and stresses could be generated at levels of respiratory effort that clinicians frequently observe in patients with Covid-19. “Our modeling revealed that patients with acute hypoxemic respiratory failure may be at significant risk for self-inflicted lung injury due to increased respiratory efforts; these efforts must therefore be monitored and controlled during care“, underlines Professor Declan Bates of the University of Warwick.

This occurrence of self-inflicted lung injury, however, remains controversial among intensive care specialists. According to some clinicians, there is no proof of these effects. But for others, these self-inflicted lesions would be a reality involving the use of mechanical ventilation in some patients to avoid it. Without deciding with certainty on this subject, Professor Declan Bates specifies that “patients should always follow the advice of their clinicians regarding the timing of initiation of oxygen therapy, noninvasive ventilation, or mechanical ventilation“.