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 PaO 2 in mechanically ventilated patients at their baseline FiO 2 and baseline FiO 2 +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 PaO 2 . This modification may be a valuable in circumstances where there is a relative shortage of oxygen.