List of ongoing registered RCTs on helmet NIV
| Trial | Registration | Interventions | Design | Countries | N |
| Helmet-COVID | NCT04477668 | Helmet versus usual care | Multicentre RCT | Saudi Arabia and Kuwait | 320 |
| Comparison of High-Flow Nasal Oxygen, Face-Mask NIV and Helmet NIV in COVID-19 ARDS Patients | NCT04715243 | High-flow nasal oxygen versus helmet NIV versus mask NIV | Multicentre RCT | Oman | 360 |
| Helmet CPAP vs High-Flow Nasal Oxygen in COVID-19 | NCT04395807 | High-flow nasal oxygen versus helmet CPAP | Single-centre RCT | Sweden | 120 |
| High-Flow Nasal Oxygen vs CPAP Helmet in COVID-19 Pneumonia | NCT04381923 | High-flow nasal oxygen versus helmet CPAP | Single-centre RCT | USA | 200 |
| Early CPAP in COVID-19 Patients with Respiratory failure (EC-COVID-RCT) | NCT04326075 | Early helmet CPAP versus usual care | Single-centre RCT | Italy | 900 |
Helmet-COVID, Helmet Non-Invasive Ventilation for COVID-19; NIV, non-invasive ventilation; RCT, randomised controlled trial.