In defence of extrapolation but not improvisation in SARS-CoV-2 lung disease.

Recently, the struggle against COVID-19 by respiratory and intensive care clinicians worldwide was punctuated by the sound of calls from a number of influential publications for an end to, as it were, improvisation and a return to principles of evidence-based medicine. The message was that management of SARS-CoV-2 lung disease needed to be guided strictly according to established dogma in acute respiratory distress syndrome unless supplanted by clinical trials specific to COVID-19. This position is predicated on the assumptions that knowledge about acute respiratory distress syndrome, and only about that entity, is directly translatable to SARS-CoV-2 lung disease, and that clinical trials enrolling COVID-19 patients will be completed in a sufficiently timely and rigorous fashion to influence empirical practice during the current pandemic. Clearly, there is room for an alternative perspective. In this Viewpoint, we aim to articulate a contrary point of view by resorting to arguments that are likely to resonate with frontline clinicians battling COVID-19.