Final answer:
A Nasal Cannula delivers an estimated O2 concentration of about 36% at 6 lpm and up to 40% at 8 lpm, with each 1 lpm increase raising the concentration by roughly 4%.
Step-by-step explanation:
The concentration (%) of O2 delivered by a Nasal Cannula at a flow rate of 6-8 liters per minute (lpm) is generally estimated to be between 24% and 40%. The exact concentration depends on factors like the patient's breathing pattern. For a Nasal Cannula, each increase of 1 lpm typically increases the delivered O2 concentration by about 4%. So, at 6 lpm the concentration can be approximately 36%, and at 8 lpm it could be up to 40%.