Monday, June 16, 2008

Some are more sensitive than others.

Over the years of being a Respiratory Therapist I have learned a few different schools of though on the use of oxygen and how effective it is at different levels.

It has varied from:

  • 100% Nonrebreather to in reality a 70-80% nonrebreather. A lot of nurses actually believe it is really 100% oxygen the NRB is giving.
  • OWL protocol, or Oxygen With Love. This actually really seemed to work and what it was used for was to decrease the occurrences of retinal detachment in babies in the NICU. The protol was to keep the SPO2 level between 88-92%. We all know that high levels of oxygen can cause retinal detachment in infants, well this protocol actually worked, it decreased the amount of infant that needed eye surgery due retinal detachment from around 60% down to below 20% at the hospital I worked at. So did it work, I think so.
  • You need a bubbler with oxygen. No you don't, not always. I do give them our for levels over 4 lpm on the nasal cannula IF they are at that level for awhile, or they are getting bloody or burning nares.
  • All Post-Op patient need 2lpm of O2 for 12hrs after surgery. I think not.
  • Anything under 2 lpm with a Nasal Cannula is a worthless on a adult.
That last one is a area that I'm dealing with right now. All of the other hospitals that I have worked for we were in the school of thought that under 2 lpm, you might as well just take them off because it doesn't do anything for that patient.

For some reason that has been true so far for me and my patients, until I started here at my current hospital. I recently had 3 different patient who I just couldn't wean off of oxygen. They were a 15 month old, a 60 year old and a 83 year old and they were all on the under 2 lpm levels of oxygen, which seemed to be the kicker.

Now that 15 month old I do understand that pediatric patients do respond to lower levels of oxygen flow, which is why they make a low flow oxygen flowmeter which goes from 0.1 to 1 lpm. This patient had a possible pneumonia but great sounding lung sounds after a day, but we could not get this child off of the 0.1-0.2 lpm of oxygen. She would drop to the mid to low 80's without it and as soon as I put it back on, poof back up to the high 90's.

Then the 60 year old I had. This person was a long term smoker, probably had COPD also so I would assume that this person lived in the low 90s to the high 80s. But what was interesting is that on RA this patient would drop down to 80% so we would put 0.5 lpm O2 on and the sats would jump back up to 97% right away. Seriously 1/2 lpm and the spo2 would jump that high. I was amazed. I had always learned that under 2 lpm was a waste of oxygen and equipment.

Now the last patient, my 83 year old was the same way. I was doing my oxygen rounds and I checked her spo2 on 1 lpm and she was 99% on the 1 liter. Great I though, I can take her off the oxygen, which I did. I then came back in a hour just to make sure that the sats were fine and wow was I shocked. 78% on RA!!!! I'm thinking, "Really no kidding, that 1 liter made that much difference with her!!!". Well it did, I put her back on the 1 liter of O2 and BoooYahhh, it shot right up to 97%. Amazing.

This was in the same night, all three of them had their oxygen issues. This night right here disapproved the idea to me that anything under 2 liters per minute of oxygen is worthless in adults, I was a skeptic but now I think I might be a believer. Even most of the books say a nasal cannula is set between 2-6 lpm and 24-36%. Now 1/2 lpm is 23% according to the formula:

21% + (oxygen liters per minute *3) = fio2.

That there is under the book definition of the nasal cannula, but it seems to do some good. Oh well as long as they are not dying on me and it's that 1 lpm that is keeping them from doing so, I will keep using the lower levels now as needed.

if anyone has any information or web sites about the lower levels of oxygen on adults I would be very interesting in that information, because like I said I have always heard it worthless under 2 lpm, but apparently some patients are more sensitive than others.

Drive on RT's and thanks for reading.


Freadom said...

Great post. I might have to link to this on my blog.

KokomoCRT said...

I glad to see someone else think that bublers are not always necessary. I also love it when they call you and say there SaO2 is 83% and you look at the patient looks great and amazingly you change the probe to another finger or ear and sao2 is reall high 90's.

Djanvk said...

Thanks freadom for the comment.

I know exactly what your saying, it's always funny to look at the RN's and see their faces after that.

William said...

Remember that nasal cannulas have a variable fio2 based on a pts respiratory pattern. This could explain why some patients drop so much from taking that 1L off.. because its actually closer to a FiO2 of 30 than 24. And then, if they become SOB, their WOB increases, along with their O2 consumption (and increases anxiety...) which might explain going from 1L99 to RA 78.

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