Helmet Non-Invasive Ventilation for COVID-19 Patients

Inclusion Criteria: * Suspected or confirmed COVID-19 * Aged ≥14 years old at the participating ICU. ICUs that use other age cut-off for adult patients will adhere to their local standard (16 or 18 years) * Acute hypoxemic respiratory failure based on PaO2/FiO2 ratio \<200 despite supplemental oxygen with a partial or non-rebreathing mask at a flow rate \>10 L/min or above * Intact airway protective gag reflex * Able to follow instructions (e.g. squeeze hand on command, eye contact with care provider, stick out tongue on command, etc.) Exclusion Criteria: * Prior intubation during this hospital admission * Cardiopulmonary arrest * Glasgow coma scale \<12 * Tracheostomy * Upper airway obstruction * Active epistaxis * Requirement for more than one vasopressor to maintain mean arterial pressure \> 65 mm Hg * Pregnancy * Imminent intubation * Patients with do not intubate orders or equivalent * Enrolled in another trial for which co-enrolment is not approved including trials on mechanical ventilation * Patients already treated with helmet * Patients with chronic carbon dioxide retention (PaCO2 \>45) * Previous enrolment in this trial * The primary cause of respiratory failure is not heart failure as judged by the treating team