the study was not initiated, no subjects enrolled.

The objective of the study is to evaluate the efficacy of helmet NIV in reducing the duration of invasive mechanical ventilation in order to minimize ventilator needs during the COVID-19 pandemic.

Single center randomized clinical trial investigating the efficacy of helmet NIV used for early liberation from mechanical ventilation in patients with acute hypoxemic respiratory failure.

Intervention: Helmet group Patients randomized to the intervention group will be extubated to helmet NIV without a spontaneous breathing trial. The helmet will be connected to oxygen and room air flow meter to deliver a minimum of 60L of fresh gas flow and a PEEP valve. The PEEP will be increased using a PEEP valve in increments of 2-3 cmH20 to improve peripheral oxygen saturation of at least 90% at an inspired oxygen requirement (FiO2) of ≤ 60%.14 After application of the helmet, arterial blood gas sampling will be utilized to follow gas-exchange; this is a part of usual care for the management of patients with acute hypoxemic respiratory failure. Noninvasive support will be reduced progressively in accordance to clinical improvement and will be discontinued if patient maintains respiratory rate <30breaths/min and PaO2 >75mm Hg with FiO2 0.5 without ventilatory support. If endotracheal intubation is required, the helmet will be removed and the patient will be intubated without delay.

Control: Usual Care Patient randomized to the control group will continue invasive mechanical ventilation until the following weaning criteria are met:15 Resolution or improvement of the condition leading to intubation Hemodynamic stability, defined as systolic blood pressure between 90 and 160 mm Hg and heart rate less than 140/min without vasopressors or with low doses of vasopressors Glasgow Coma Scale score of 13 or greater Respiratory stability (oxygen saturation >90% with fraction of inspired oxygen [Fio2] ≤0.4, respiratory rate <35/min, Noncopious secretions (<3 aspirations in the last 8 hours).

Once weaning criteria are met, patients will undergo a spontaneous breathing trial for 30 minutes on pressure support mode. Criteria for failure to tolerate the SBT were agitation, anxiety, low level of consciousness (Glasgow Coma Scale score <13), respiratory rate higher than 35/min and/or use of accessory muscles, oxygen saturation by pulse oximetry less than 90% with Fio2 higher than 0.5, heart rate higher than 140/min or greater than a 20% increase from baseline, systolic blood pressure lower than 90 mm Hg, or development of arrhythmia. If the spontaneous breathing trial is successful, then the patient will be extubated.

Subjects will be followed for long term followup at 90 day and 1year mortality

Inclusion Criteria:

Age ≥18 years old on mechanical ventilation for at least 48 hours Positive End Expiratory Pressure (PEEP) level between 8 to 13cm H20 The ratio between the partial pressure of oxygen and fraction of inspired oxygen (PaO2/FiO2) between 150 and 300 mmHg with FiO2≤0.6 pH≥7.25 Respiratory rate (RR)≤30/min Adequate gag and cough reflex Ability to spontaneously breathe

Exclusion Criteria:

Hemodynamic instability (Systolic blood pressure <90 or requiring >2 vasoactive agents) Tracheostomy Upper airway obstruction Pregnancy Elevated intracranial pressure Upper airway obstruction Glasgow coma scale ≤ 8 Patients who refuse to undergo endotracheal intubation, whatever the initial therapeutic approach