Final answer:
The highest flow rate appropriate for nasal cannulae is 6 L/min, and higher flow rates may require alternative oxygen delivery systems due to potential discomfort and mucosal drying.
Step-by-step explanation:
The highest flow rate that is typically recommended for a nasal cannula is 6 L/min (c). Nasal cannulae are used to provide supplemental oxygen to patients requiring respiratory support. They are preferred for their ease of use and patient comfort, especially over long durations. Flow rates over 6 L/min are not usually recommended as they can lead to discomfort and drying of the nasal mucosa. Patients requiring higher oxygen flows may need alternative delivery systems such as a face mask or high flow nasal cannula systems that can deliver up to 60 L/min. It's important to note that the actual flow rate must be tailored to the individual patient's need and tolerance, as determined by their healthcare provider.