A partial rebreather mask is used for oxygen therapy. It delivers oxygen gas to the patient at concentrations of 50 to 70 percent. Slightly different than other types of masks, the partial rebreather mask has a bag that collects exhaled air.
With a partial rebreather mask, when the patient inhales, they inhale some of the exhaled air, which contains carbon dioxide. When carbon dioxide enters the lungs, it stimulates breathing. In contrast, non-rebreather masks have vents on the side of the mask that allow all exhaled air to escape. Patients using this kind of mask breathe in fresh oxygen gas at concentrations of 80 to 90 percent.