In their editorial about ‘COVID-19 pneumonia: different respiratory treatment for different phenotypes’ Gattinoni et al. hypothesize a sequence of events in critically ill patients infected by SARS-CoV-2. They describe a type L characterized by a low elastance, a low ventilation to perfusion ratio, a low lung weight and a low lung recruitability. Worsening patients are supposed to progress from type L to type H. Type H is characterized by a high elastance, a high right-to-left shunt, a high lung weight and a high lung recruitability. As Gattinoni and colleagues complete their editorial, “understanding the correct pathophysiology is crucial to establishing the basis for appropriate treatment”.