What is the estimated percentage of oxygen delivered from a non-rebreather mask?

A non-rebreather mask is designed to deliver high concentrations of oxygen to patients who require it. It is capable of delivering approximately 90% to 100% oxygen when correctly fitted and used. The mask features a reservoir bag that fills with oxygen, allowing the patient to inhale a significant volume of oxygen with each breath while minimizing the entry of ambient air, which is vital for patients with respiratory distress or those requiring immediate oxygen support.

The estimation of around 95% as the percentage of oxygen delivered reflects the mask's effectiveness in providing oxygen therapy. Additionally, it is important to note the key role of the one-way valves on the mask that prevent exhaled carbon dioxide from entering the reservoir bag, ensuring a higher concentration of oxygen is available to the patient.

In contrast, other provided options represent lower oxygen percentage estimates that do not accurately reflect the capabilities of a non-rebreather mask under proper usage conditions. Understanding the requirements for oxygen therapy and the use of different delivery systems is essential for effective patient care in emergency situations.