Considerations for the use and study of exogenous surfactant in respiratory disease from COVID-19

Exogenous surfactant therapy has been widely studied in acute respiratory distress syndrome (ARDS) but has failed to show mortality benefit in several trials. The COVID-19 pandemic has renewed interest in exogenous surfactant, and clinical trials are investigating surfactant therapy in COVID-19 respiratory disease. There is biological plausibility of benefit from surfactant, and patients who are early in their disease and do not meet full ARDS diagnostic criteria may respond differently, and perhaps more favourably, to surfactant therapy. Clinical trials that investigate patients with severe ARDS have a high likelihood of reproducing already known findings of surfactant therapy and systematically exclude patients who might exhibit a novel response to exogenous surfactant.