COVID-19(84) SARS-CoV-2(20) mechanical ventilation(16) airway management(15) Abstract(12) Tracheal intubation.(10) intensive care(9) Patient(8) coronavirus(8) Infection prevention and control(8) infection control(7) Trial(6) outcome(6) clinical(6) hospital(6) Personal protective equipment(6) ARDS(6) Mortality(5) Volume(5) titre(5) predicted(5) acute respiratory syndrome(5) prospective cohort study(5) China(5) Control(4) significantly(4) Other(4) declined(4) Immune status(4) Neutralising Antibodies(4)