Which oxygen delivery device is most appropriate for a patient with severe respiratory distress who needs high concentrations of oxygen?

The nonrebreather mask is the most appropriate oxygen delivery device for a patient experiencing severe respiratory distress who requires high concentrations of oxygen. This device is specifically designed to deliver high-flow oxygen, typically providing concentrations of 80% to 100% oxygen, which is crucial for patients in serious conditions where rapid and effective oxygenation is needed.

The nonrebreather mask features a one-way valve that prevents exhaled air from entering the oxygen reservoir bag, allowing the patient to inhale high concentrations of oxygen without dilution from ambient air. This mechanism ensures that the patient is receiving the maximum possible oxygen concentration, which is vital in cases of severe hypoxia or respiratory failure.

In contrast, the simple face mask delivers lower concentrations of oxygen compared to the nonrebreather mask, usually between 40% and 60% oxygen, and does not effectively manage higher oxygen demands during acute respiratory distress. The nasal cannula, while convenient and comfortable for use in less severe cases, typically supplies only about 24% to 44% oxygen and may not meet the needs of a patient in severe distress. The Venturi mask, although useful for precise control of oxygen concentrations, generally provides lower percentages of oxygen compared to a nonrebreather mask and is