O2 flow...

Standard nasal cannula

The standard nasal cannula delivers an inspiratory oxygen fraction (FI,O₂) of 24-40% at supply flows ranging from 1-5 L-min. The formula is FI,O₂ = 20% + (4 × oxygen litre flow). The FI,O₂ is influenced by breath rate, tidal volume and pathophysiology. The slower the inspiratory flow the higher the FI,O₂.

20%+(4* 0.125)=20+.5=20.5% or 21% (room air). Only 100% O2 is non-rebreather.

You are not providing the infant with more oxygen because they are breathing in room air around the cannula (mask is not sealed around the face). Since the oxygen is flowing into the nose at a higher pressure than the surrounding air, when they take a breath it requires less effort to breathe.

If they are in room air with a flow we usually say that it helps keep the airway and air sacs open a little bit better than baby can by himself.

We have a chart that gives us a rough estimate of what with what percent equals. Yes, we just call it 1/8thL 100% .

I want to make sure I explain this correctly to parents when they ask why the baby still needs oxygen if he/she is at 21%. I hear the other nurses and RT's say, "he is getting the same O2 as you and me, it's just that he's getting more flow."

I am correct in saying that while the oxygen concentration is the same as what we are breathing, at 21%, the baby is basicaly having the air pushed at him. No one explains the concept of "more flow" to the parents and they often seem just as perplexed as before they asked the question.

Also, on the O2 subject, what percentage is O2 delivered via nasal canula. For example, if a baby is recieving a 1/8 liter, off the wall with no blender, is it considered 100% 02 at 1/8th liter?

Sorry if these are silly questions, but I'm relatively new to NICU and these two things have been bugging me.

Thanks

The infants you describe probably don't really need the oxygen, they need the flow, or rather pressure. Higher flow rates simulate CPAP and this helps keep the infant's alveoli open. With more recruited alveoli, the infant has more surface area for exchanging gases.

Our unit doesn't permit us to chart RA unless the infant is off of all respiratory support. Otherwise we need to chart 2L/21% or CPAP 5cm/21%.

I wouldn't worry too much about the exact percentage of O2 delivered from a non-blended cannula, it's providing 100% though the infant may be getting the equivalent of 24 or 28%, it's not really relevant. I would just worry about charting it as 1/8th L/min non-blended or "off the wall".

I've always found it easier for them to understand when I use "pressure" instead of "flow". And yeah. 1/8L otw is 100% o2.