Can you have too much oxygen?

[S.L. Ping Beauty]

Because of the altitude where I live, I am on O2  in addition to the CPAP. Prescribed level is 2 LPM.

I will most likely be adjusting that level based on a comment in   THIS THREAD    for when I purchase the heated hose alluded. I should perhaps buy a basic O2 level monitor for home use reference, but the levels are always good based on doctors visits, it was 94% this past week.

But is there any downside to turning it up?  With all due respect to Nigel Tufnel, why not 4, 5 or 6 LPM, or heaven forbid  11!

Is there any harm in too much oxygen?

[Sleeprider]

Monitoring SpO2 is really the only effective way to optimize supplemental oxygen with CPAP. I wrote a wiki that may help http://www.apneaboard.com/wiki/index.php..._with_CPAP

[mesenteria]

This is purely a philosophical/economics statement, and nothing more: Yes, you can have to much of pretty much anything.  When it is squandered, unneeded, or in excess of a reasonable regimen or demand, what goes by unused, but paid for or acquired with energy, is indeed wasted.  

I don't know what you use for supplemental oxygen, but whether it is supplied in a pressure vessel for depleting use over time, or supplied via a generator, what you can't really use is a waste.  If the lowest saturation is going to be in the mid-90's on any one night, and you are otherwise being well-treated, I don't see why you would want to administer, and have flow by unused, any more oxygen.

[Sleeprider]

This is purely a philosophical/economics statement, and nothing more: Yes, you can have to much of pretty much anything.  When it is squandered, unneeded, or in excess of a reasonable regimen or demand, what goes by unused, but paid for or acquired with energy, is indeed wasted.  

I don't know what you use for supplemental oxygen, but whether it is supplied in a pressure vessel for depleting use over time, or supplied via a generator, what you can't really use is a waste.  If the lowest saturation is going to be in the mid-90's on any one night, and you are otherwise being well-treated, I don't see why you would want to administer, and have flow by unused, any more oxygen.

The use of oxygen by SLPB is related to altitude.  At the elevation where he lives (10,000 feet) the partial pressure of oxygen is significantly less than at sea level.  I am unfamiliar with the extent to which he has adapted to the altitude in terms of fitness, hemoglobin, lung capacity, etc, but supplemental oxygen may have a important therapeutic value and may even reverse high altitude pulmonary edema (although I doubt anything that serious is in play).  Anyway, this article discusses some of the applications of supplemental oxygen at high altitude, and I'm sure it provides a benefit that can be felt. https://www.ncbi.nlm.nih.gov /pmc/articles/PMC1114067/

[SarcasticDave94]

I did some research about a year ago with prep in mind that I'd need supplemental oxygen because of COPD. I came across a segment that did say too much was bad. It was not with the mindset of some pulmonary duck/doc that if you mess with the settings you'll blow up a lung. It seemed to me they actually had evidence to back their argument.

I forget exactly what the reasoning was, but I vaguely remember it was that too much oxygen threw off the natural body system gases balance or something like that. More oxygen than naturally found means it has displaced something else. In doing so, it upset a needed blood gas balance I think was the bottom line.

Sorry I can't be specific, but my internal RAM is flawed and too random now.

PS if I come across that info, I can put acceptable link-ish stuff on a post

[SarcasticDave94]

a quick research hit but not what I was referring to:

Too much oxygen can possibly lead to these 2 things that may be bad:

1) lowering Respiratory drive via skewing carbon dioxide to oxygen ratio and pushing your body away from homeostasis-the natural balance it seeks to maintain, it then suppresses breathing drive similar or equal to central apnea-brain doesn't see need to replace oxygen because it thinks it's already got enough in the system

2) a thing called pulmonary oxygen toxicity-irritated lungs and coughing which leads to fluid collection in lungs

[OpalRose]

Dave,
I’ve also read that caution should be exercised. Too much oxygen (if you don’t need it) can be harmful to some.
A simple google search will bring up much info.

Even living at high elevations, I would assume that S.L.P.B. is following doctor’s recommendations in regard to his oxygen use and not just raising it too high without doctors consent.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3227706/

[Matt00926]

Well no concentrator that I have seen will pump out anywhere near 11LPM. So then you're looking at medical grade oxygen tanks. The downside being they are expensive, very heavy, and you're stuck working with some medical supply company forever. And if you want to go outside, the time limit would be a few hours before you had to replace the tank.

If I were you I would just move if you can. If you have health problems living at altitude is hurting you.

There isn't any value to an oxygen saturation of 100% as compared to 95%.

[mesenteria]

This is along my lines of reasoning as well.

Sleep Rider, thanks very much for your answer, and for the link you provided.  I lived at 14K in the Andes in several mining communities during the 60's for nine years, and have personal experience with adaptation to the reduced atmospheric pressure at that altitude.  The company policy was to hire people only provisionally for one year, but if you were not able to adapt within 6 months, you were terminated.  Unfortunately, the very 'odd' person could not, and their history with the corporation ended.  The heavy (and healthy) majority of people did adapt, their blood thickened, their diaphragms grew stronger to draw in greater volumes of air, their lungs expanded, and they went on to work successfully for many years at those dizzying heights.

Purely from a mechanical and financial standpoint, letting costly supplemental oxygen go by, unused by the patient, is probably best minimized if it is not possible, or practical, to eliminate it altogether.  If our asker's nadir is only 94% for saturation, using more oxygen would only be desirable if it is needed and if it will be drawn into the blood stream effectively.  I don't know what delivery method we're talking about, but...……………………………………….I guess the asker needs to shed some light on his circumstances. Does he sleep with an effective seal that would raise the localized atmospheric pressure topically...direct to his lungs? Is this strictly needed when his desats fall only to 94%? I'm not a physician, and have yet to learn if that level during sleep is not conducive to long-term health. If it is, and our friend is not doing so well, will supplemental oxygen help him enough during sleep to overcome the longer time in deficit which he must surely deal with during his working day?

[Sleeprider]

I'll just say the Wiki I wrote o Oxygen Bleed suggests that a 2-L/min oxygen supplement to CPAP is not very much. I included equations to estimate the O2 increase at 1 and 3 L/min supplement:

Scenario 1 at 1-litres/minute oxygen addition at 100% and assuming a total CPAP flow of 30 L/min:
(1-L/min x 100% O2) + (30-L/min x 21% O2) = 730/31-L/min = 23.55% Oxygen.

Scenario 2 at 3-litre/minute oxygen at 100% and assuming a total CPAP flow of 30 L/min:
(3-L/min x 100%O2) + (30-L/min x 21% O2) = 930/33 L/min = 28.18% oxygen.

Any variable can be changed based on available data. If the flow rate is 40 L/min from the CPAP, the oxygen concentrations will be lower. If leaks are present or pressure results in a higher average vent-rate, the oxygen concentrations will also be lower. If a mask with less vent rate is used, then concentrations of oxygen will increase.

So all considered a 2 L/min supplement is likely about 25% oxygen at 10,000 feet, or effectively equal to sea level. I used to be totally acclimated to altitude and observed many people that suffered acute symptoms at higher elevation, including the dangerous symptoms of HAPE. While there was a time I could run at high elevation, today I might be one of those people that experienced severe altitude related symptoms. I did bicycle at over 9000 feet this year, so I'm not quite done yet.