O2 percentages and liters

[smartnurse1982]

Ok,please help me with this,as I feel like an idiot,and of course,none of the 5 nursing supervisors know nothing,I kid you not? Nobody could answer this question at my office.

I have a pt who wears a trach collar at night. Her orders state"pt may have up to 10L o2 to keep sats greater than 93%. She usually needs some o2 at night,but this is where confusion comes in.

Here is the strange part: On top of the humidifier cup,there are percentages of o2.

It can be turned to 21%,28%,40%,60%,80%,and 100%. On the flow sheets,we have nurses who put down she is receiving 1L of 02,and others put down 8L,and it differs night to night.

What I guessing is that the ones who put down 2L/min are turning the dial to 100% 02,and the ones like me who use 6L are leaving the dial at 40%.

I have never seen a cup like that before,as usually the humidifier cup doesn't have that on it.

Now,we know we can manipulate it to be put at 28%,40%,and so on so that she recieves more or less of the mist. I don't think any of the other nurses understand either,to be honest,because I left notes for them,and nobody responded back.

Nursing supervisor states just put the Liters down instead of Fio2...

So,child is recieveing 1L/min one night for 8hrs,and 8L/min for 8 hrs the next night.

I wonder how we would explain that to the insurance company when they review the notes.

[nurseprnRN, BSN, RN]

Oh btw,we aren't charting Fi02 at all; we just chart the 02 flow rate.

Which, as Gemi points out so clearly, is meaningless. Now your challenge is to make everyone there understand why. I loved RT issues when I did ICU and hyperbarics (same equations, different reasons). A good RT inservice, repeated for everyone, will help your patients immensely.

[caliotter3]

BTW- smartnurse1982, good for you for asking, at least. Keep doing that. Its for the safety of your patients, and the betterment of your own nursing experience and judgement.

I asked this question one time and look at the answer I got. (Don't remember, maybe that was the correct answer for the problem at hand back then). I never pursued it further at the time because no adjusting was necessary for the patient to maintain the required sats. Also tried to look it up myself and ran into problems finding this info. Thanks for the useful info Gemi!

[Esme12, ASN, BSN, RN]

Any patient with a trach collar should have a humidifier. Humidifiers come with the Fi02% dials. In my opinion, the order was written inappropriately and the charting is messed up. really scary to have nurses charting things they have no idea about.

A patient is on a high flow device. i.e. trach collar. In order to use a trach collar appropriately, the FLOW RATE must be set at 10-12LPM. THIS DOES NOT MEAN the patient receives 10L of oxygen. This is where the dial comes on. You adjust the dial percentage to a patient saturation to maintain 93% as written. That is why you get here more "noise" as you turn the dial to a lower flow. Because more air is escaping into the atmosphere. The higher you turn up the dial, you hear less "noise" because all the oxygen is being delivered to the patient through the trach collar.

The order should had been written, adjust trach collar Fi02 up to 60% to maintain sats greater than 93%. 10L of oxygen delivered from a simple face mask or high flow cannula is approximately 60% Fio2.

Its almost unnecessary to even chart the flow rate of 6L. If the trach collar is used appropriately, it should ALWAYS be at a flow rate greater than 10L. Thats a given. The only thing you should really be charting is the fi02. By charting 6L at 40%, you aren't using the trach collar appropriately. So you really don't know how much oxygen the patient is REALLY getting.

Im an icu nurse x 8 years. I know this. Or ask a respiratory therapist.

THIS!

[TraumaSurfer]

Any patient with a trach collar should have a humidifier. Humidifiers come with the Fi02% dials. In my opinion, the order was written inappropriately and the charting is messed up. really scary to have nurses charting things they have no idea about.

A patient is on a high flow device. i.e. trach collar. In order to use a trach collar appropriately, the FLOW RATE must be set at 10-12LPM. THIS DOES NOT MEAN the patient receives 10L of oxygen. This is where the dial comes on. You adjust the dial percentage to a patient saturation to maintain 93% as written. That is why you get here more "noise" as you turn the dial to a lower flow. Because more air is escaping into the atmosphere. The higher you turn up the dial, you hear less "noise" because all the oxygen is being delivered to the patient through the trach collar.

The order should had been written, adjust trach collar Fi02 up to 60% to maintain sats greater than 93%. 10L of oxygen delivered from a simple face mask or high flow cannula is approximately 60% Fio2.

Its almost unnecessary to even chart the flow rate of 6L. If the trach collar is used appropriately, it should ALWAYS be at a flow rate greater than 10L. Thats a given. The only thing you should really be charting is the fi02. By charting 6L at 40%, you aren't using the trach collar appropriately. So you really don't know how much oxygen the patient is REALLY getting.

Im an icu nurse x 8 years. I know this. Or ask a respiratory therapist.

I agree with most of your post but there are some major concepts which need to be cleared up.

The "FiO2" dial on oxygen devices are not allowing "air to escape". These O2 devices are ran by what is known at a Venturi system based on the principle of Bernoulli and air entrainment.

http://www.respiratoryupdate.com/members/Air_Entrainment_Mask_Venturi.cfm

For every part of oxygen, X amount of air must be entrained to blend for the set FiO2. Due to the ability to entrain large liter amounts of air, this makes a venturi device "high flow" and should meet the patient's inspiratory demands. But, the higher the FiO2 the smaller the opening gets and the less flow is entrained. This is why these aerosol devices are most effective at low FiO2s (less than 50%). Know the limitations of your device as patients might increase their flow AND FiO2 demand.

Venturi and Bernoulli are the basic principles of ALL oxygen equipment. The goal is to deliver enough flow to meet patient demand and in the case of a trach mask achieve the goal of humidification. (This is also why some hospitals have a policy of no bubblers on Nasal Cannulas less than 4 liters but that is another discussion.)

Also note that water particles can change FiO2 and/or the total flow delivery which is why humidifiers are not placed on Venturi masks or most low flow masks like Simple and non rebreathers.

Too many get caught up in the 1 L = 24%, 2 L = 28% crap which is only good for exam purposes and does not address the many different devices for O2 delivery or the many patient factors which influence FiO2. Some very bad adverse patient events have occurred because health care providers have tried to utilized that very over simplified concept on all devices. Hence you get the 2 L NC patient who is a mouth breather when sleeping and gets placed on a 2 L simple mask. Some also see the simple mask and the venturi mask as being the same. If one can run at 2 L so can the other. Now you also get some with this way of thinking for the trach mask.

Some RTs or RN managers will just tell the nurses to run a humidifier at 10 L minute or more just so they don't have to try to explain Venturi.

What some LTC facilities have done to avoid errors is run the humidifier off compressed air (wall or industrial size air compressor) at 8 - 12 L/M and bleed in O2 into the circuit. The delivered FiO2 will vary depending on the flow from the compressor but at least those who have a difficult time understanding the O2 devices can chart "liter flow". The humidifier will also be turned to 100% to close the opening and make it quieter.

If the FiO2 device is set at a specific O2 and the correct liter flow is set, the patient will probably get close to that FiO2 provided they are not breathing more for inspiratory demand than the delivery device. Luckily, these are high flow devices meaning they entrain a lot of air but the higher the FiO2 the less air will be entrained. THAT is where some get into trouble. They believe the patient is getting "100%" FiO2 when the dial is set at 100% but there is no entrainment. If the patient is breathing hard and fast, they will entrain from around the mask. If the mask is improperly placed, definitely not 100%. A trach collar is effective at lower FiO2 just like the Venturi mask.

There are a few high flow humidifiers which can go up to 40 or even 60 liters if demand is great. Sometimes the RTs will hook up two humidifiers on a Y connectors. They will run both humidifiers at the same FiO2 to achieve a more precise percentage. The patient will have their flow and FiO2 demands both met. Some may have seen RTs adjusting the flow setting on a ventilator. Flow must meet demand.

BTW: For all who had EMT or Paramedic training prior to becoming a nurse, a non-rebreather mask is not a high flow device. It is a low flow. Changing the flow on it to decrease "FiO2" does the patient a big disservice and accomplishes very little. Also "rigging" devices when you do not understand the basic principles of oxygen delivery is dangerous even if you have been told someone has always done it that way.

All the "text book" percentages on low flow devices (NC, simple mask, non rebreather mask) you memorized for a test were based on a mathematical formula for an "average" sized person breathing at rest a VT of 500 and a RR of 12 with a consistent inspiratory liter flow for a MV of 6 Liters.

References;

The above link, Respiratory Update is Dana Oakes' website and has all the books available online for reference.

From Nursing Times, a good explanation of devices;

Short-term oxygen therapy | Practice | Nursing Times

Here is a good article for Pediatrics. The basic principles are the same. Notice how much Total Flow decreases through a Venturi device as FiO2 increases.

http://pedsccm.org/FILE-CABINET/Practical/Akron_pdfs/4OXYGEN.PDF

Take an RT quiz.

http://www.actx.edu/respiratory/files/filecabinet/folder11/1410lab_04delivery_devices.pdf

RT Book of Calculations. This should also be a MUST READ for all critical care nurses.

Respiratory Care Calculations, 3rd ed. - David W. Chang - Google Books

[Gemi523]

Might I add, scary too, the physician wrote this order. Resident, I hope? Not like that makes it acceptable when dealing with people's lives. It truly is up to the nurse to double check a physicians order! Nurses have a lot of responsibility and accountability. Seems unfair that our license is on the line because we have to ensure a physicians order, who has 2 times more education than RN's, is safe and accurate. Educate, educate, educate yourself and others! :)

Like another poster said, red flags were seen when people say they don't know or are charting different things. Like I said, good for you for asking. But be mindful, even on nursing forums, the information your receive may not always be accurate. The best thing to do is ask someone specialized like an RT or a published resource like even going back to some of your nursing books. Also, your facility SHOULD have policies and procedures for everything. Sometimes you can also google policies and procedures from other academic hospitals just to compare.

[TraumaSurfer]

Might I add, scary too, the physician wrote this order. Resident, I hope? Not like that makes it acceptable when dealing with people's lives.

The physician might write orders for 10 different hospitals, facilities or units. All might use different equipment.

Have the doctor write for SpO2 (>/) and your facility or unit should have a policy for what FiO2 point is not acceptable or can be safely maintained. Inform the doctor of that and tell him or her to expect a call if that setting is reached or a doctor might wish to be called for any increases in FiO2.

Sometimes the doctors feel they must micro manage O2 equipment and in some places they must. But, if they are not familiar with the equipment or assume you use the same as the unit across the hall, they look stupid when they shouldn't.

Some hospitals have different purchasing systems and use different equipment which leads to errors. The ED might have nursing purchasing VentiMasks and RT might purchase for the ICUs. But, they might purchase different brands and you get different colored adapters with different flows for the same FiO2. This is the same when too many cooks in the same hospital individually try to buy defibrillators, pulse oximeters and CR monitors. None of the equipment talks to the other's devices.

[Gemi523]

Thanks for all that info Traumasurfer! I think simple concepts are more of the immediate concern for this poster in order to at least deliver care and chart things that actually make sense and can withhold in court. Doesn't sound like this is an ICU setting with patients where we need to factor in tidal volume, respiratory rate, end tidal volumes, etc. If those factors mattered in this case, I don't think this patient would be on a trach collar unless it was a trach collar trial but still very much labile with a vent nearby.

Even in the ICU, we obviously don't compute percentage of oxygen equivalent to lpm. It's completely irrelevant since are many other factors involved with a patient on a vent to consider such as peep, pressure, vent setting, and actual patient physiological o2 consumption and ventilation.

As you stated, the calculation should only be a reference for more "normal" patients. And like I said, this doesn't sound to be an ICU and the patient, since he/she is on a trach collar, seems respiratory stable.

[TraumaSurfer]

The principles still apply for O2 delivery devices regardless of location (ICU or SNF). You just have to know what type and have some working knowledge of each device.

Most of my info and references pertain more to LTC. In California we do not have RTs in SNFs, LTC or even on the med surg floors. The education is left up to nursing which is why some of us have tried to get as much info as possible. You will eventually see fewer and fewer RTs everywhere as reimbursement dwindles even more for that profession. So, study up on the O2 stuff.

I did list what some facilities have had to do in order to prevent errors. That included running the humidifier off compressed air and doing O2 bleed in. But, when some will then switch to the O2 flow meter for the humidifier you will again get error. Some don't notice the flow meter when looking at the humidifier.

The other is to tape the insert for FiO2 which comes with ever bottle to the bottle.

The other issue is some charting systems on med surg, SNFs or LTC facilities only allow for liter flow. That will need to be addressed. The same for CNA charting.

Overall, consistency. Pick a system, educate, re-educate and stick to it with frequent QA monitoring.

[wooh, BSN, RN]

Might I add, scary too, the physician wrote this order.

Docs don't always understand the O2 equipment. Pulmonologists will, but otherwise, it tends to be very hit and miss.

General rule of thumb: If you can adjust the percentage, the liters mean nothing. (Exception: you have a patient that's on a high flow delivery system.)

The liters are adjusted with these devices SOLELY to get the machine to be able to make its percentage.

If you have a Venturi system, when you adjust the percentage, it will say next to it how many liters to set it at. The liters are just what it takes to make it work. It has NOTHING to do with what the patient is getting. That is solely the percentage.

With trach collars and similar devices, the blender will require a certain amount of O2 going to it. Generally it's the max liters you can send to it. It doesn't mean they're on "15 liters" or anything like that. You can be on room air with it set at 15 liters. The percentage is what matters. The blender will take care of that for you, it just needs enough flow going into it to create the humidified air coming out.

Basically what's happening, is if you put this patient on 1L and attach it to their trach, you're suffocating the poor patient. Y'all need an RT to explain this to all of you and to get the order straightened out.

[smartnurse1982]

Ok,thanks everyone.

Unfortunately,i can't get into contact with an RT,as I'm a private duty nurse.

The RT set up the equipment;I'm surprised he didn't tell the Aunt anything about the FiO2.

[smartnurse1982]

Not even sure how to get to 12L/min 02..

We use a 02 concentrator,not a tank.

[smartnurse1982]

After this pt has been in the hospital for a year an a half,she came home with the same orders.

The RT said adjust the liters,as the 02 concentrator only goes up to 10L/min.

I wonder,how can i show this page to a nursing supervisor without outing myself?