A Pilot Study Comparing Oxygen Delivery Via Helmet Interface Versus High Flow Nasal Cannula

Exclusion Criteria

• •1. P/F Ratio \< 100 (Severe ARDS) on quantifiable FiO2
• •2. More than 24 hours has elapsed since the patient met criteria for AHRF (Inclusion #2 and 3, above)
• •3. Urgent need for intubation
• •Criteria for intubation:
• •i. RR\>40 ii. Lack of improvement of respiratory muscle fatigue iii. Copious tracheal secretions that require frequent suctioning iv. Acidosis with a potential Hydrogen (pH) \<7.35 v. Acute hypercarbia (PaCO2 \> 45 mm Hg) vi. SpO2 \< 88% for more than 5 minutes despite FiO2 and non-invasive support vii. Respiratory or cardiac arrest viii. Glasgow Coma Scale ≤ 8
• •4. Contraindication to HFNC, Helmet-NIPPV, or Mask-NIPPV
• •5. Upper airway obstruction, facial trauma
• •6. Copious secretions, airway bleeding, epistaxis or vomiting
• •7. Primary cause of respiratory failure is exacerbation of chronic obstructive pulmonary disease (COPD) or asthma
• •8. Elevated intracranial pressure \>20 mm Hg
• •9. Home mechanical ventilation except for CPAP/BiPAP used solely for sleep disordered breathing
• •10. Persistent hemodynamic instability (systolic blood pressure (SBP)\<90 or mean arterial pressure (MAP)\<60 despite IV fluid resuscitation, or norepinephrine dose \> 0.1 mcg/kg/min or equivalent vasopressor dose)
• •11. Plan for procedure during which NIPPV or HFNC is contraindicated. Okay to enroll if procedure is complete and AHRF persists within 24 hours.
• •12. Absence of airway protective gag reflex or cough
• •13. Tracheostomy
• •14. Lack of informed consent
• •15. Pregnancy
• •16. Actual body weight exceeding 1 kg per cm of height
• •17. Diffuse alveolar hemorrhage
• •18. Severe acute pancreatitis as etiology for hypoxemia
• •19. Recent upper gastrointestinal surgical anastomosis within the past 30 days
• •20. Enrollment in another clinical trial within the past 30 days
• •21. Unsuitable for non-invasive ventilation in the judgment of the treating MD
• •22. Decision to withhold life-sustaining treatment. Patients with Do-Not-Resuscitate (DNR) or No Cardiopulmonary resuscitation (No CPR) order may be enrolled.
• •23. Do not intubate order