NichtRebreathingMaske

The NichtRebreathingMaske, translated as non-rebreather mask, is a medical device used to deliver oxygen to patients who are breathing independently but require a higher concentration of oxygen than is typically found in ambient air. This mask is characterized by a reservoir bag attached to a mask that covers both the nose and mouth. The bag is filled with a high concentration of oxygen from a medical oxygen supply.

During inhalation, the patient draws oxygen from the reservoir bag. Crucially, the mask is designed with one-way valves. These valves prevent the patient from rebreathing their exhaled air, which contains a higher concentration of carbon dioxide. Instead, the exhaled air is directed outwards through separate exhalation valves, preventing it from entering the reservoir bag. This ensures that the patient consistently receives a high FiO2 (fraction of inspired oxygen), typically between 60% and 80%, depending on the oxygen flow rate and the patient's respiratory rate and tidal volume.

Non-rebreather masks are commonly used in emergency medicine, intensive care units, and other settings where rapid and effective oxygen delivery is necessary. They are indicated for patients experiencing hypoxia, respiratory distress, or other conditions requiring supplemental oxygen. While effective, proper fitting of the mask is essential to prevent leaks and ensure optimal oxygen delivery. The flow rate to the reservoir bag must be sufficient to keep it inflated during inhalation.