The existence of ventilation/ventilator-induced lung injury (VILI) during spontaneous breathing cannot be denied, as it has been shown experimentally [
1] and, at least, suspected in some clinical circumstances [
2]. Therefore it is nonsense to be pro or con towards the facts. One, however, may be pro or con the opinion that spontaneous breathing, either with or without mechanical ventilation, favors a lower occurrence of ventilator-induced lung injury (VILI) compared to mechanical ventilation alone. Before discussing this problem, it is convenient to precisely define the VILI and the conditions for its development. …