In vivo assessment of a modification of a domiciliary ventilator which reduces oxygen consumption in mechanically ventilated patients.

There are instances where hospitals may experience a relative shortage of oxygen, for example, future pandemics, natural disasters or wartime. We developed a modification to a domiciliary ventilator that captures oxygen normally vented during expiration into the atmosphere, delivering it to the patient. The modification significantly increases PaO₂ in mechanically ventilated patients at their baseline FiO₂ and baseline FiO₂ +1, +2 and +3 L/min compared to no modification. The modification reduces walled oxygen consumption by median (IQR) -1.0 (-1.25 to -1.00) L/min whilst maintaining PaO₂. This modification may be a valuable in circumstances where there is a relative shortage of oxygen.