Helmet CPAP Versus HFNC in COVID-19

Study Overview
=================
Brief Summary
-----------------
We aim to investigate whether the use of Continuous Positive Airway Pressure using a Helmet device (Helmet CPAP) will increase the number of days alive and free of ventilator within 28 days compared to the use of a High Flow Nasal Cannula (HFNC) in patients admitted to Helsingborg Hospital, Sweden, suffering from COVID-19 and an acute hypoxic respiratory failure.

Detailed Description
-----------------
A detailed description can be found in the study protocol published in Trials in Dec 2020: Tverring, J., Åkesson, A. & Nielsen, N. Helmet continuous positive airway pressure versus high-flow nasal cannula in COVID-19: a pragmatic randomised clinical trial (COVID HELMET). Trials 21, 994 (2020). https://doi.org/10.1186/s13063-020-04863-5

Official Title
-----------------
Helmet Continuous Positive Airway Pressure Versus High-Flow Nasal Cannula in COVID-19: A Pragmatic Randomised Clinical Trial

Conditions
-----------------
COVID, Acute Hypoxemic Respiratory Failure

Intervention / Treatment
-----------------
* Device: Helmet CPAP
* Device: HFNC


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria (all of the following): Age ≥ 18 years Sars-Cov-2 found in the upper or lower respiratory tract by PCR during the current disease episode Peripheral oxygen saturation (SpO2) < 92 % despite conventional low-flow oxygen therapy of at least 6 L /min for at least 15 min A decision to initiate HFNC or Helmet CPAP by the attending ward physician The patient has given written informed consent to participate. Exclusion Criteria (any of the following): Need for direct admission to the intensive care unit for mechanical ventilation Unconsciousness or drowsiness Pneumothorax Carbon dioxide pressure (pCO2) > 6 kPa in venous blood gas (VBG) Underlying chronic obstructive pulmonary disease stage III-IV A decision not to participate Inability to comprehend the study content and give informed consent

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Helmet CPAP<br>Helmet Continuous Positive Airway Pressure (CaStar hood for CPAP therapy by Starmed/Intersurgical) driven by high-flow blender (Bio-Med Devices). | Device: Helmet CPAP<br>* Start-up air flow 40 L/min. Start-up PEEP 5 cmH2O. Max PEEP 20 cmH2O. Oxygen flow / FiO2% according to 92% SpO2 target. Titrations at physician's choice.<br>|
| Active Comparator: HFNC<br>High-Flow Nasal Cannula (OptiflowTM nasal high-flow interface) driven by AIRVO 2 humidification system (Fisher and Paykel) | Device: HFNC<br>* Start-up air flow 30 L/min. Max air flow 60 L/min. Oxygen flow / FiO2% according to 92% SpO2 target. Titrations at physician's choice.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ventilator-Free Days (VFD) | Number of days alive and free of mechanical ventilation within 28 days. Patients who die within 28 days will be counted as 0 VFD. Time in ventilator will be counted in hours and rounded to whole days. | 28 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SpO2/FiO2-ratio | Peripheral oxygen saturation divided by fraction of inspired oxygen | 1 hour after randomisation | 
| Patient comfort | Visual scale (1-10) | 24 hours after randomisation | 
| Frequency of endotracheal intubation | Min 0, Max 1 | 28 days | 
| Frequency of carbon dioxide rebreathing | Defined as pCO2 > 6 kPa in a venous blood gas. Min 0, Max ∞ | 28 days | 
| Days alive within | All-cause mortality. (180 days endpoint not in primary publication) | 28 days and 180 days |