Inclusion Criteria:  1) patients who are admitted to the adult ICU 2) deemed to require NIV, as per the clinical team, for acute respiratory failure.  Exclusion Criteria:  1) with impending cardiac arrest or need for intubation 2) Glasgow coma scale <9 3) tracheostomy or upper airway obstruction 4) elevated intracranial pressure 5) untreated pneumothorax 6) who refuse endotracheal intubation (do not intubate order documented) 7) facial trauma 8) are unable to wear the helmet or facemask 9) who use NIV chronically