Quote from wooh
If he was on 28%, he was on 28%, and was NOT on 4L. This is a case where the liters mean nothing. The percentage is what counts.
Someone correct me on this, but the only time I can think of that you have both a flow rate AND percentage that both mean something, is high flow nasal cannula. But that's because the flow in that case is actually more of a pressure setting, like you'd have with BiPAP or CPAP.
When you have a venturi or HAM or trach collar, the O2 liter setting from the wall is just what the particular equipment requires to turn it into the percentage.
28% on a trach collar? I love to transport patients when they're that stable!
You are right. In any case where you are utilizing a Venturi device whether it be on a trach collar or Venturi mask, the flow does not matter. You can blast 15 liters through the system, and it will only deliver the set fio2. I am a registered respiratory therapist and RN, and this is a common misconception with a lot of folks.