Which of the following flow rates is too high for a standard nasal cannula?

Standard nasal cannulas are typically used to deliver supplemental oxygen at flow rates between 1 to 6 liters per minute. At these flow rates, they provide a comfortable level of oxygen to patients without excessive discomfort.

When the flow rate exceeds 6 liters per minute, there may be discomfort for the patient, including irritation to the nasal passages and a drying of the mucous membranes. Higher flow rates can cause the nasal cannula to become less efficient, and it can also lead to the creation of a higher pressure at the nostrils, potentially leading to less effective oxygen delivery.

At 8 liters per minute, the flow rate surpasses the standard safe limit for a nasal cannula, making it unsuitable for effective and comfortable use. Thus, this option represents a flow rate that is considered too high for standard nasal cannula application.