Helmet NIV vs. CPAP vs. High-flow Nasal Oxygen in Hypoxemic Respiratory Failure

Study Overview
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Brief Summary
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Multicenter, open label, three-arm randomized trial to assess the effect of helmet noninvasive ventilation vs. helmet continuous positive airway pressure vs. high-flow nasal oxygen on the rate of endotracheal intubation of patients with acute moderate-to-severe hypoxemic respiratory failure

Detailed Description
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The optimal initial management of acute hypoxemic respiratory failure is uncertain. Helmet noninvasive ventilation and high-flow nasal oxygen appear as the most promising techniques in this setting. Recently, the first head-to-head randomized trial compared first-line continuous treatment with helmet pressure support ventilation with specific settings (PEEP=12 cmH2O pressure and pressure support=10-12 cmH2O) vs. high-flow nasal oxygen alone in patients with moderate-to-severe hypoxemic respiratory failure. Results showed no significant inter-group difference in the days free of respiratory support at 28 days, but lower intubation rate and increased 28-day invasive ventilation-free days in the helmet group. Use of helmet noninvasive ventilation is less frequent than use of helmet continuous positive airway pressure, which is simpler to use. The investigators designed an open-label, multicentre randomized trial to assess the effect of helmet pressure support ventilation and continuous airway pressure as compared to high-flow nasal oxygen on the intubation rate of patients with moderate-to-severe hypoxemic respiratory failure in the intensive care unit.

Official Title
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Helmet Noninvasive Ventilation vs. Continuous Positive Airway Pressure vs. High-flow Nasal Oxygen as First-line Treatment of Acute Hypoxemic Respiratory Failure (HENIVOT2). An Open-label, Multicentre Randomized Trial

Conditions
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Respiratory Failure, Hypoxemic Respiratory Failure

Intervention / Treatment
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* Device: Noninvasive respiratory support


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Acute symptoms of respiratory failure PaO2/FiO2 ratio ≤ 200; PaCO2≤45mmHg; Absence of history of chronic respiratory failure or moderate to severe cardiac insufficiency (NYHA>2 or left ventricular ejection fraction<50%); Informed consent Patients that have already received NIV, CPAP continuously for more than 24 hours before the screening visit will be excluded. Other Exclusion Criteria: Pregnancy; Exacerbation of asthma or chronic obstructive pulmonary disease; Hypercapnia (PaCO2>45 mmHg) with or without respiratory acidosis; More than 2 organ failures, including the lung. Documented pneumothorax; Clinical diagnosis of Cardiogenic pulmonary edema; Haemodynamic instability (Systolic blood pressure<90 mmHg or mean arterial pressure<65mmHg) and/or lactic acidosis (lactate>5 mmol/L) and/or clinically diagnosed Shock requiring administration of vasoactive agents (norepinephrine>0.1 mcg/Kg/min); Metabolic Acidosis (pH <7.30 with normal- or hypo-carbia); Chronic kidney failure requiring dialysis before ICU admission; Chronic hypoxemic respiratory failure requiring long-term oxygen therapy; Altered neurological status that requires immediate intubation and/or making the patient uncooperative; Urgent need for endotracheal intubation, according to the decision of the attending physician; Do not intubate order; Decision of withdrawal of life-sustaining therapy; Thoracic or abdominal surgery in the previous 7 days; Any condition that makes the patient very likely to require endotracheal intubation due to a reason different from respiratory failure; Recent head surgery or anatomy that prevent the application of helmet or HFNC to patient's face.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Helmet Noninvasive ventilation (NIV)<br>Patients in helmet noninvasive ventilation group will receive continuous helmet pressure support ventilation for at least 16 hours/day in the first 2 calendar days. Dedicated helmets for noninvasive ventilation will be applied and size will be chosen according to patient's neck circumference. Each patient will be connected to a mechanical ventilator ventilator through a bitube circuit with no humidification. The ventilator will be set in PSV-NIV mode, with the following suggested settings [34-38]: initial pressure support=12 cmH2O and adequate to permit a peak inspiratory flow of 100 l/min; positive end-expiratory pressure=12 cmH2O. FiO2 will be titrated to obtain an SpO2≥92% and ≤98%. Inspiratory flow trigger = 2 l/min or according to the practice of each institution; fastest pressurization time; expiratory trigger: 10-50% of the maximum inspiratory flow, eventually modified to avoid double triggering; maximum inspiratory time 1.2 second. | Device: Noninvasive respiratory support<br>* Treatment of acute hypoxemic respiratory failure<br>|
| Experimental: Helmet continuous airway pressure (CPAP)<br>Patients in CPAP group will receive continuous helmet CPAP for at least 16 hours/day in the first 2 calendar days. Continuous CPAP without interruptions will be strongly encouraged in the first 48 hours of treatment. Dedicated helmets for noninvasive ventilation will be applied and size will be chosen according to patient's neck circumference. Treatment will be delivered through a high-flow generator. The following settings will be applied: Continuous air flow>45 l/min. Bi-tube circuit with no humidification, Y-piece with heat and moisture exchanger, or active heating and humidification with humidification chamber temperature set at 31 °C, 34 °C or 37 °C according to patients' comfort. Expiratory positive end-expiratory pressure valve set to achieve PEEP=12 cmH2O. FiO2 will be titrated to obtain an SpO2≥92% and ≤98%. | Device: Noninvasive respiratory support<br>* Treatment of acute hypoxemic respiratory failure<br>|
| Active Comparator: High-flow nasal oxygen<br>Initial set flow will be 50-60 l/min and flows will be decreased. in case of intolerance and/or according to patients' requirements: flows≥30 L/min will be mandatory in all enrolled patients. Humidification chamber will be set at 31 °C, 34 °C or 37 °C according to patient's comfort. FiO2 will be titrated to obtain an SpO2≥92% and ≤98%. Weaning the patient from high-flow will be considered only after 48 hours from enrolment and will be discouraged until the patients is considered for ICU discharge. | Device: Noninvasive respiratory support<br>* Treatment of acute hypoxemic respiratory failure<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of Endotracheal intubation | The proportion of patients requiring endotracheal intubation according to predefined criteria | 28 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Days free of invasive mechanical ventilation at day 28 | The number of days in which patients do not receive mechanical ventilation within 28 days from randomization | 28 days | 
| Days free of invasive mechanical ventilation at day 60 | The number of days in which patients do not receive mechanical ventilation within 60 days from randomization | 60 days | 
| Days free of invasive mechanical ventilation at day 90 | The number of days in which patients do not receive mechanical ventilation within 60 days from randomization | 90 days | 
| Rate of In-intensive care unit mortality | All-cause mortality, assessed at the discharge from the intensive care unit | 90 days | 
| Rate of In-hospital care unit mortality | All-cause mortality, assessed at the discharge from the hospital | 90 days | 
| Rate of 90-day mortality | All-cause 90-day mortality | 90 days | 
| 90-day ICU free days | The days not spent in the intensive care unit by the patient on a 90-day basis | 90 days | 
| 90-day hospital free days | The days not spent in the hospital by the patient on a 90-day basis | 90 days | 
| Incidence of pneumonia | Incidence of pneumonia, diagnosed after the treatment start and during the ICU stay | 90 days | 
| Incidence of shock | Incidence of shock, diagnosed after treatment start and during the ICU stay | 90 days | 
| Incidence of barotrauma | Incidence of barotrauma, defined as pneumothorax o pneumomediastinum after treatment start and during the ICU stay | 90 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Noninvasive ventilation, High-flow nasal oxygen, Mechanical ventilation