respirator mask for copd patients

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Specializes in ER.

hello to all you pulmonary nurses out there, a group of my nursing school buddies called me last night wanting to know what oxygen mask is more appropriate for a copd patient, all of us except one thought it was the venturi mask. our textbook, for all the money it costs, does not give a clear cut answer. could someone please satisfy "inquiring minds"? thanks a million and happy holidays

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A venturi mask delivers a more precise FIO2 which can be important in COPD patients who are oxygen sensitive ( those that have a compensated respiratory acidosis on ABGs). FIO2s range from .28 to .60 on a venturi mask system and is regulated by the color coded air entrainment devices. Simple O2 masks need to be run at a liter flow of al least 5- 6 lpm and deliver anywhere from .30 - .60 or above depending on the patient's own inspiratory flow and tidal volume making it a less desirable system for COPD patients who need a specific lower FIO2.

Hope this helps

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hello to all you pulmonary nurses out there, a group of my nursing school buddies called me last night wanting to know what oxygen mask is more appropriate for a copd patient, all of us except one thought it was the venturi mask. our textbook, for all the money it costs, does not give a clear cut answer. could someone please satisfy "inquiring minds"? thanks a million and happy holidays

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Venti Mask is the right answer BUT the WHY is more important than the WHAT

C O P D rs walk around with a very love Pa O2 level and Saturation.Now if you

give a C O P Dr and O2% higher than say 28% then the chemo receptors will

measure the O2 he is taking in and it is say 50% Venti Mask the receptors

will regester more than enough O2 and shut his breathing down. This is also

called NITROGEN WASHOUT which means a change in the patients Acid/Base balance Remember that a Nasal Canula can be used burt only at a low flow rate,say 2-3 L P M. Don't look for a Saturation of 98% rather 70% because that is what they walk around with daily.If C.O.P.D.r needs more than 28%

they should be intubated and ventilated,so that their breathing won't stop.

Make sure the DR. orders L P M C' nasal canulla because O2% cannot be measured. Hope this helps in many ways. NRSDUG :crying2:

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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Venti Mask is the right answer BUT the WHY is more important than the WHAT

C O P D rs walk around with a very love Pa O2 level and Saturation.Now if you

give a C O P Dr and O2% higher than say 28% then the chemo receptors will

measure the O2 he is taking in and it is say 50% Venti Mask the receptors

will regester more than enough O2 and shut his breathing down. This is also

called NITROGEN WASHOUT which means a change in the patients Acid/Base balance Remember that a Nasal Canula can be used burt only at a low flow rate,say 2-3 L P M. Don't look for a Saturation of 98% rather 70% because that is what they walk around with daily.If C.O.P.D.r needs more than 28%

they should be intubated and ventilated,so that their breathing won't stop.

Make sure the DR. orders L P M C' nasal canulla because O2% cannot be measured. Hope this helps in many ways. NRSDUG :crying2:

Wait a minute. . . COPDers may have a lower sat than 98% but it sure isn't as low 70%. If you allow it to go this low you had better have a ventilater on hand because that pt will begin hyperventilating to increase oxygenation then tire out giving you a respiratory rate of 0. Oxygen induced hypoventilation (which is what you TRYING are describing) is extremely rare. When aneasthesia at our hospital walks in the icu and starts babbling about it the other RT's and I laugh. If the pt is critical enough all efforts should be made to oxygenate regardless of possible hypoventilation.

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Hey Y'all

Great links there NurseKaren! I hope thats how NursingEducation is going in the 21st century. My nursing school made a big deal about the difference between chronic bronchitis and chronic obstructive diseases with the result that we students evaluated our COPD pts by trying to peg them as 'pink puffers' and 'blue bloaters'. LOL!!! Today I don't even remember which is which.

A few tho'ts: Everybody needs enough Oxygen to fuel their cells (John likes to get down to basics!) and an accurate saturation number of 70% won't do it. Even MY few remaining neurons wouldn't work too well. There is a fascinating lil' ol' graph that should be in that textbook called the "OXYHEMOGLOBIN DISASSOCIATION CURVE''. It's unfortunately the kind of thing that makes Nurses' and Students' eyes glaze over, but the core idea is not so hard to figure.

I tend to give baby nurses that I run into a little talk comparing the RedBloodCell to a pickup truck with a loader/unloader person in the back with a shovel...but I won't type in the whole essay 'cause it's too long.

Cut to the chase and make two points. (When's he gonna get to the point!")

First, you can't trust Pulse Oximeters with your COPD pts. The low range of sats is UNRELIABLE. When nurses crank up the O2 on their COPD folks to get that nice 98% that we like, there is a population of 'lLungers' that will have a pCO2 through the roof and the blood will turn acid and they'll end up Ventilator dependent. (It's very bad management of COPD-ers to put them on the Vent if it can be prevented 'cause getting them off is a terrible chore.)

Second, Nitrogen washout is not very relevant. It also happens when too-high Oxygen is used on a pt, yes. But it's bad for EVERYONE and the pathology goes like this: The air we take into our ALVEOLUS is 70% nitrogen. It is inert, doesn't do anything FOR us exactly except take up space--think of it as the 'popcorn' you put in a package you're sending. It's not the gift, but it keeps the box from collapsing, right?

Put anybody on 100% Oxygen for very long and--besides being bad for the epithelial cells (they get OXIDIXED--DUH)--the alveoli collapse. Why? Because the 'popcorn' wasn't in the box. You see, the blood is really really good at sucking the O2 out of the alveoli it brushes up against. When ONLY OXYGEN is in the aveolus, and that Oxygen gets sucked out, the alveolus collapses. And because they are MUCH harder to re-open and they are to KEEP open, thats also bad form. So use Oxygen as medication--carefully and cautiously and VMasks are the best tool for the job cause you can 'titrate' the O2 up and down.

Breathing hard after all that...

Papaw John

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Specializes in Hemodialysis, Home Health.

That was good stuff, Papawjohn !

I learned something today ! :)

I understood the caution about too high O2 useage with COPD, and the problematic acidosis, but I liked your analogies and explanations.

Hope to read more good stuff from you soon, on other subjects as well.

Enjoyed the learning.. keep on teaching ! :D

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Hey Jnette

Thanx for the words. But you have to be careful and don't get me started!

My kids used to tell their friends: "Don't ask Daddy a question!! We'll never get out of here!!"

Papaw John

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hello to all you pulmonary nurses out there, a group of my nursing school buddies called me last night wanting to know what oxygen mask is more appropriate for a copd patient, all of us except one thought it was the venturi mask. our textbook, for all the money it costs, does not give a clear cut answer. could someone please satisfy "inquiring minds"? thanks a million and happy holidays

hmm...what sort of mask.. if a pt is a mouth breather, go for a venturi mask..but also,ther's nothing wrong w/ using a nasal cannula to COPD pts(esp. those who doesnt fancy keeping a mask on their faces)..as long as u know how to convert into LPM via nasal cannula ur venturi O2..

so basically, on air, our FiO2 is 21%..1 LPM n/c wld be 24%, 2LPM = 28%..just add 4% for every 1LPM..and so forth ...BUT..not more than 4 LPM please, as much as possible..wc is 32%..if its just while the neb is going through and pt is on 40% venturi,it shld be fyn to use 5LPM n/c..

just sharing...

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Try to keep a COPDer's SaO2 88%-92% (which is a PaO2 of about 60 mmHg, the shoulder of the oxyhemoglobin curve). A baseline ABG might be nice, too.

BTW- remember this tidbit "40 50 60, 70 80 90" which means a PaO2 of 40 mmHg roughly corresponds to a SaO2 of 70%, 50 mmHg to 80%, and 60 mmHg to 90%. A PaO2 of 40 mmHg is end-organ damage.

Remember that a "true" COPDer is probably on home O2, so start with the home prescription (usually 2-3 L/m via nasal cannula) and titrate upwards carefully. Carbon dioxide retention causing hypoventilation is overblown, but it is out there. Quite often the patient will do it fairly rapidly right in front of you, though. If you don't have an ABG, look at the lytes. If the CO2 is above 30 they are possibly a retainer, so keep a close eye on them. Also stay away from sedatives in COPD.

Mouth breathing is a problem when calculating FiO2 using the 4% per L/m formula. Constant flow of oxygen into the reservoir of the nasopharynx is drawn into the lungs with each breath. Increased mouth breathing of room air will dilute the oxygen for a lower FiO2 overall, which is why a venturi mask (constant FiO2 at a constant minute volume) is the most certain way to deliver a particular FiO2. And yes, if a COPDer needs more than 50% FiO2 to maintain a SaO2 of 88% and are getting sleepy, they need a vent.

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A COPD pt, would normally thrive w/ low pO2 anyway.. It 'swhat we call the hypoxic drive.unlyk us normal peeps. Chronically evidenced w/ and elevated HCO3 and BE most of the tym to compensate their pH. I wouldnt worry if they have a pO2 of 8, cuz a lot of them have been hypoxic all their lives anyway. More accurate delivery of FiO2 is without a doubt via a venturi, cuz when theyr acutely exacerbated and when distressed they become mouth breathers in an attempt to blow off CO2.. A good SpO2 doesnt all the tym indicate the pts ventilation is well..they may have sats of >95%, but guess what? the CO2 is already on the ceiling..thus they become drowsy and unresponsive.. due to acidosis..

the more O2 we deliver, the more they will retain CO2..when CO2 reacts w/ water it will form carbonic acid, thus the ph goes down.. acidosis occurs...

Tho there are COPD who are not chronic retainers.. as much as possible keep pt from receiving too much O2 ..just enough to perfuse and maintain their respi drive active..

too much 02 is toxic as we all know, careful Px of it shld be monitored.. we give Hi FiO2 if only if it is a lyf threatening situation...

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How long will it take for the high flow O2 to shut a COPDer down to vent status?

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