Which oxygen delivery device is best suited for a patient who requires a precise concentration of oxygen?

A. Nasal cannula: The nasal cannula provides low-flow oxygen with variable concentrations depending on the patient's respiratory rate and tidal volume. It does not deliver a precise or consistent oxygen concentration. B. Simple face mask: The simple face mask delivers moderate concentrations of oxygen, generally between 40–60%, but it lacks a mechanism for precise control. Oxygen delivery fluctuates based on the patient’s breathing pattern and flow rate. C. Venturi mask: The Venturi mask is designed to deliver a specific and consistent concentration of oxygen by using color-coded adaptors that mix oxygen with room air at fixed ratios. This makes it ideal for patients who require accurate oxygen titration, such as those with COPD. D. Non-rebreather mask: A non-rebreather mask delivers high concentrations of oxygen (up to 90–100%) but does not allow for fine control of the exact oxygen percentage. It is used in emergencies when high oxygen delivery is needed, not for precise regulation.