The non-rebreather mask is utilized for patients with physical trauma, chronic airway limitation, cluster headache, smoke inhalation, and carbon monoxide poisoning, or any other patients who require high-concentration oxygen, but do not require breathing assistance.
The non-rebreather mask covers both the nose and mouth of the patient. It attaches with the use of an elastic cord around the patient’s head, and an attached reservoir bag. It is typically one liter size bag, that connects to an external oxygen tank or bulk oxygen supply system. Before mask is placed on the patient, the reservoir bag is inflated to greater than two-thirds full of oxygen, at a rate of 15 liters per minute (lpm). Approximately ¹⁄₃ of the air from the reservoir is depleted as the patient inhales, and it is then replaced by the flow from the O2 supply. If the bag becomes completely deflated, the patient will no longer have a source of air to breathe.
Comparing to common oxygen mask, non-rebreather mask provides higher and more stable concentration oxygen gas.