For a non-rebreather mask (NRB), what is the required flow rate of oxygen?

A non-rebreather mask is designed to deliver a high concentration of oxygen to patients who are critically ill or experiencing severe respiratory distress. The required flow rate for a non-rebreather mask is typically set at 15 liters per minute. This flow rate ensures that the mask can provide the patient with an adequate supply of oxygen while also preventing the inhalation of room air.

At this flow rate, the reservoir bag attached to the mask remains inflated, which is crucial for both effective delivery of oxygen and the prevention of carbon dioxide buildup in the mask, since it minimizes rebreathing exhaled air. A non-rebreather mask can deliver approximately 80-100% oxygen to the patient, depending on various factors, including the patient’s respiratory effort and the fit of the mask.

Lower flow rates, such as those indicated in some of the other options, would not adequately fill the reservoir bag and could lead to a decrease in the oxygen delivery performance, making the use of lower flow rates unsuitable in critical situations requiring high-flow oxygen therapy.