As the second wave of the coronavirus pandemic hits hospitals, the hiss and bubble of advanced respiratory support is an increasingly familiar sound on medical wards.

This is because some patients who become severely unwell with COVID-19 suffer from respiratory failure and so require breathing support.

This support can be both invasive, where a ventilator delivers air to the patient via a tube inserted into the windpipe, or non-invasive, where patients are assisted using devices that remain outside the body.

Non-invasive techniques are not new, but the pandemic has transformed how they are used. Previously not in routine use outside of the ICU, they have become a standard of care.