HOW PULSE OXIMETERY WORKS AND IDEAL LEVELS (NB!)

[LoQ]

A week later my family doc looked over the report and told me my SpO2 was low enough enough often enough to warrant supplemental O2 at night. He sent a prescription for it to the DME. I haven't heard anything, so the insurance company probably wouldn't pay for it.

You don't really need the insurance company, correct, since you already have a concentrator?

I'm glad you have a doc on board. That's encouraging that your primary care doctor was willing to do it. It will certainly make things easier.

Correct me if I am wrong, but my understanding is that the chief cost is the concentrator, then there are minor costs like tubing. Unless you are on oxygen during the day, there is no need for the machines that can fill bottles, correct?

I've seen concentrators, new, for sale for figures between $500 and $1000. Is that the kind you need, or do you need one of those multi-thousand dollar machines ($2000 to $3000 or more)? I don't know what the difference is between them all but would appreciate it if you could give some pointers on that stuff.

[frh]

LoQ, I found a Respironics EverFlo oxygen concentrator on Craigslist earlier this year and bought it for my wife so she wouldn't have to drag the tube up and down the stairs. Since I started using it, she is back to dragging a 50' tube up and down stairs. I asked the doctor for a prescription because I would rather use supplemental O2 with his permission. He offered to send the prescription to the DME, so I decided to find out if they would actually fill it.

[LoQ]

Thank you, gvz, for the quick, easy tutorial. I doubt that information could have been conveyed better.

LoQ, I found a Respironics EverFlo oxygen concentrator on Craigslist earlier this year and bought it for my wife so she wouldn't have to drag the tube up and down the stairs. Since I started using it, she is back to dragging a 50' tube up and down stairs. I asked the doctor for a prescription because I would rather use supplemental O2 with his permission. He offered to send the prescription to the DME, so I decided to find out if they would actually fill it.

I have seen them on Craigslist, but hesitated to buy because I don't know how to assess a used one. How did you determine that it was in working order? If you go to buy a used one, how do you know if it works properly or not? I suppose that because the price difference between new and used is only a couple hundred dollars, if you could buy it new without an Rx, that would be superior, but I would still look at a used machine if it were reasonably priced.

I, for one, would be very interested in whether or not your DME will fill the Rx, meaning insurance will pay. If so, I would be particularly interested in whether insurance normally buys a machine outright in the case of PAP therapy or rents it. The only people I know who have been on oxygen rent machines, but based on what gvz said, they must have been the more expensive pulse machines because they are not on PAP therapy to my knowledge.

Another thing I would like to figure out is which machines are the quietest, and what other issues matter.

[Tielman]

Just trying to understand why doctors are so miserly with oxygen.

I think the status-quo medical treatment paradigm for supplemental O2, to date, has been largely about: 1) avoiding hypoxemia at the cellular level, or 2) stabilizing central respiration. I'm unaware of medical studies/literature supporting a reasonable-sounding hypothesis that supplemental O2 might be able to enhance sleep architecture by means unrelated to those two objectives (eg. supplemental O2 addressing hyper-reactive chemoreceptor-based sleep disturbances in at least some highly arousable patients).

Here are a couple links that discuss the benefits of using supplemental O2 as well as contraindications and a few other non-medical complications:

LONG TERM OXYGEN THERAPY IN ADULTS
-and-
SUPPLEMENTAL LOW FLOW OXYGEN TITRATION IN POLYSOMNOGRAPHIC TECHNOLOGY
(an Adobe PDF document)

I'm confused.

I thought I read (in several places) that O2 therapy can be used *instead* of CPAP for treatment of mild/moderate OSA, and was shown effective.

Then for those that are having therapy issues with low O2 levels, then shouldn't the prescription of O2 be supported.

[Tielman]

Im also an EMT, as well as sleep tech, and on the ambulance we add O2 to anything below 90%. I see O2 in the 50's in the lab all the time. Amazing these people even function at all!

Interesting jobs! At what point in the lab do you add O2?

At my diagnostic sleep test, I went well below 80 for a considerable period of time, and they did not start oxygen.

At my titration test, they were able to clear all obstructive events (though I had 4 central events during REM) and my oxygen was below 90% for about 18% of the night. They did not recommend oxygen.


Just trying to understand why doctors are so miserly with oxygen. Some of us think it might help us a lot.

Interesting. My sleep lab was in a Hospital, and within the first few hours of sleep they came in and gave me 2L of O2. I was later told that although my SpO2 levels were down to 78, and they don't know how far it could have dropped, because the supplemental O2 kept it above that for the rest of the night.

[LoQ]

I'm confused.

I thought I read (in several places) that O2 therapy can be used *instead* of CPAP for treatment of mild/moderate OSA, and was shown effective.

I haven't read that anywhere, do you have a reference? Is it possible you are remembering a study which showed that use of a nasal cannula, similar to those used in oxygen therapy, was sometimes effective treatment for mild/moderate OSA? My understanding is that the nasal cannula was operated with room air, not oxygen.

[LoQ]

they don't know how far it could have dropped, because the supplemental O2 kept it above that for the rest of the night.

My oxygen dropped pretty low at my titration study, but they did not give me supplemental O2. They also don't have any idea how low my oxygen might have gone, because the tech came and woke me up, disrupting the downward slide of my oxygen level. Apparently she was concerned about how low my oxygen was getting and didn't want it to drop further and apparently didn't want to start O2.

You would think that would have been evidence enough to do titration, but instead, they tested me next for narcolepsy.

[-SWS]

I thought I read (in several places) that O2 therapy can be used *instead* of CPAP for treatment of mild/moderate OSA, and was shown effective.

Well now we're discussing O2 therapy in lieu of CPAP therapy----versus doctors using O2 as supplemental treatment to CPAP. I don't think O2 therapy is preferred for treatment of obstructive apnea by today's sleep doctors except in cases of CPAP failure/intolerance. But even when O2 therapy is administered for that purpose, I am under the impression that the patient's basal O2 is either maintained or elevated by that O2 for the purpose of avoiding the hypoxemic damage I had mentioned in objective number one above.

So in that alternative treatment scenario, I think the O2 alternative can sometimes help with desaturations and subsequent cellular damage. But I don't think O2 therapy can help with sleep arousals related to the more severe upper-airway apneic closures. I agree with LoQ. If you or anyone can find some of those studies, I think they would serve as interesting and informative fodder for this thread's discussion as long as totontoCPAPguy doesn't mind...

Then for those that are having therapy issues with low O2 levels, then shouldn't the prescription of O2 be supported.

I think if O2 stays low despite CPAP use, then O2 is prescribed in tandem with CPAP. But I don't think O2 therapy is typically selected over gold-standard CPAP in the year 2010 as a first choice for treatment of obstructive apnea.

[DreamDiver]

Some doctors may be a little shy of handing out oxygen because too much can kill in some instances. I don't remember all the particulars, but one RT I talked to said that some people are CO2 retainers. Under certain conditions, upping the 02 as little as a liter can actually end up suffocating the patient due to respiratory acidosis.

http://www.dailystrength.org/c/COPD_Emp ... 2-retainer

[M.D.Hosehead]

Toronto and frh:

You both feel better with the O2, maybe more energy, more alert. frh feels his short-term memory, for example,where he puts things, is better.

I'd really be interested whether you have noticed any change in higher cognitive functions--after you've had the O2 long enough to get an impression. For example, is there any difference in:


-keeping your concentration focused on the same mental problem for 20-30 minutes, for example a crossword or sudoku?

-intentionally committing something to memory, such as a short paragraph, maybe 60-100 words?

-recalling what you memorized one or two days later?

-retaining for a few hours a telephone number you heard just once?

-mentally projecting/planning into the future, for example, keeping a day's schedule and to-do list in your mind (including the order in which the items must occur)?

-remembering an appointment without writing it down?

-pacing your work so as to accomplish a larger task that has a deadline a few weeks in the future?

[LoQ]

I have seen them on Craigslist, but hesitated to buy because I don't know how to assess a used one. How did you determine that it was in working order? If you go to buy a used one, how do you know if it works properly or not?

Always should be careful with buying used medical equipment, especially if you're going to be breathing from it. You'd want to meet the seller face-to-face, try to gauge the person if possible, etc. But in addition, at least for the Invacare and Respironics machines -- they have an odometer built into them that shows you how many hours the machine has been run. I'd avoid anything with thousands of hours on it, you never know where it's been or what it's been sucking up. Also, usually there is a service-door on the back of the machines -- pop it open with a flat-head screwdriver and you'll see the built-in filter. Take a look around in there, make sure you don't see anything odd -- a nasty looking filter, or excessive dust/mold or anything else that looks abnormal.

If it looks okay, you want to be able to test it out -- turn it on, make sure it doesn't smoke, give off nasty smells or anything obviously wrong. The machines do have a "compressor" type of sound that kicks on and off every few seconds, so that sound is normal.

For the purity content -- some machines have a sensor module that will sound a alarm if the purity level drops to some threshold. Or you can spend a couple hundred bucks on an O2 Analyzer that measures the concentration level -- the machines are supposed to generate 85-95% oxygen content.

Thank you for the tips. I've learned a lot here. Even if I can get a doctor to agree to prescribe O2, this information will still be useful. It's never clear to me anymore that a DME is better than going without insurance. So much to learn...