For a child with status asthmaticus receiving helium and oxygen, what could be the actual flow rate to the non-rebreathing mask if the flowmeter is set at 10L/min?

In a scenario where a child with status asthmaticus is receiving a mixture of helium and oxygen, the flow rate delivered to a non-rebreathing mask can be influenced by several factors, including the gas mixture being used, the nature of the non-rebreathing mask, and the flowmeter settings.

When helium is combined with oxygen, the total effective flow can be different from the set flow rate on the flowmeter. Helium is less dense than oxygen, and thus, it flows more easily through the system. At a flowmeter setting of 10 L/min, the expected delivery to the patient can be higher than the set rate because of this lower density.

The actual flow rate delivered to the mask can reach up to 16 L/min when you factor in the characteristics of the non-rebreathing mask and the properties of helium. This is due to the mask allowing for a certain amount of gas entrainment from the atmosphere in addition to the supplied flow from the flowmeter.

Therefore, the calculated effective flow of 16 L/min aligns well with the dynamics of helium-oxygen therapy and the functional design of a non-rebreathing mask, making the second option the most appropriate answer.