current(5) Intervention(5) Brain(5) Direct(5) Stimulation(5) COVID-19(5) Direct Current(5) positive(5) severe hypoxemia(3) Trial(3) hospital(3) addition(3) organ dysfunction(3) groups(3) patients with COVID-19(3) patients(3) Critically ill patient(3) Noninvasive brain stimulation(3) severe ARDS(3) therapy(3) mechanical ventilation(3) defined(3) delirium(3) increase in(3) 1:1(3) respiratory(3) with COVID-19(3) Safe(3) adverse effect(3) clinical response(3)