Ventilation-induced lung injury exists in spontaneously breathing patients with acute respiratory failure: Yes

Critical care medicine has entered a new era characterized by the pre-eminence of pathophysiological medicine, mixing evidence, experience and a physiology-based approach. Physiology is a fundamental part of the knowledge needed to manage critically ill patients, but there is a large gap between knowing what is normal, i.e. physiology, and knowing what are the best solutions to cope with diseases, i.e. pathophysiology, if any. After the birth of critical care in 1952 in the Blegdham Hospital in Copenhagen [1], mechanical ventilation was universally recognized as a life-saving technique. It took many years to realize that mechanical ventilation delivered to reproduce normal physiology, i.e. achieving normal gas exchange, could injure the lungs and harm the patient [2‐4]. We collectively realized, at the expense of entire research programs, that a lung-protective ventilation was necessary [5]. We still do not understand everything, like the undisputable, though paradoxical, beneficial effect of PEEP, in a situation where “hyperinflation” was considered as the culprit. Because everything could not fit with too simple a theory, we also had hard debates around the hemodynamic effects of ventilation, often forgotten when we look at the lung [6]. Last, despite accumulating evidence, we also failed to recognize that the potential mechanisms causing ventilator-induced lung injury were for many of them simply reflecting ventilation-induced lung injury, whatever the source of breathing. …