[Equipment] O2 Concentrator: Purity of output airstream? Rental? Refurbishment? Ozone?

[joeb]

I’ve recently received an Rx from my sleep doctor for supplemental oxygen to use in conjunction with my ResMed Autosense 10.  The goal is to reduce my central apneas which often occur in clusters or for long-durations.  I’m trying to get some relief from my sleeping distress that is very high in proportion to my ‘mild’ apnea severity.
               
    My medical provider/insurer ordered a five-liter o2 concentrator for me from their contracted DME (Durable Medical Equipment) provider. The provider delivered a beast of a rental concentrator.  It had 23,000 hours on it. I measured its sound level at 70 db and it was disruptive even though it was located in the walk-out level below my upper-level bedroom. The smell from the beast’s equipment ventilation system stunk up the house with a masking-perfume scent that seemed to be intended to make one ignore that there was an probably an underlying stench that was being covered up.
 
     More disturbingly, the air supplied to my mask had a subtle, yet acrid, bitter-sweet, noxious odor that seemed to be very unhealthy. I call the odor, subtle, because it is the type of odor that I can often smell while others cannot.  To me, the smell from the o2 output of the concentrator is quite distinct, somewhat indescribable, and irksome.
 
     The next day, I reported the problem to the DME provider.  They arranged to replace the monster with a new, out-of-the-box, and concentrator.  When the machine arrived at 7:00 pm that evening, it turned out that it was also a refurbished unit, but one with only 4400 hours on it. This replacement also had an odor of a masking scent, but the odor is less-pervasive. Unfortunately, the air coming from the o2 output had the same odor and intensity as did the previous machine.
 
      I was now batting 0 for 2. I had tried two o2 concentrators, and they are the only ones I have ever tried.  Both had failed my smell test.
 
      I suspected that the refurbishing process might utilize a cleaning process for the internal plumbing that leaves a residual odor. So I asked the DME representative if any of their other customers had ever complained about an odor from the o2 output.  She said, no, but that they will try again to get me a brand new machine that has never before been used or refurbished. It should arrive tomorrow, November 16, 2021.
 
      I’ve searched the internet for O2 concentrators and the odor of their o2 output. I was surprised to find scant information about others having an experience similar to mine.  So, I’m asking the ApneaBoard if any users can comment on the experiences that they might have had with new or refurbished o2 concentrators.  Should the o2 output from these machines have any noticeable odor? 
 
       More importantly, are there any situations where an o2 concentrator becomes hazardous by outputting contaminants or ozone along with oxygen?

[SarcasticDave94]

As far as I know, the oxygen concentrator will not add ozone.

I do think you passively allowed your sleep doctor to push a supplier onto you that they're related to business-wise. This to me is a conflict of interest and never going to work good for you. You are supposed to decide with whom you deal with, not your doctor. I'm sure the doc conveniently forgot to tell you that you can choose your own DME. You've had issues with 2 machines so far, so return it and shop elsewhere for your choice of DME supplier.

Now, let's get this straight. The oxygen concentrator was scripted to combat Central Apnea or the dropping oxygen associated with Centrals? Either way, they just don't want to issue an ASV it seems. Stupid quacks. An oxygen concentrator isn't supposed to treat CA. QUACK.

Some info needed. You need to request your DETAILED reports, diagnostic sleep study, Titration if it was done, and testing involving the oxygen concentrator script. You will need to get them from Dr. Quack. When he hesitates, as I'm pretty sure shyster doc will, mention HIPAA law permits you to request and receive these. When you do get these, post redacted copies in this thread as a post.

[Jeff8356]

I don't use a concentrator (or O2 for that matter) but I have had enough procedures that I can say the smell of the new tubing and cannula is very distinct and off putting to me. I don't know if there would be a way to get rid of that smell or not.

If the concentrator is not working out for you, ask your Dr about getting bottled O2 instead. It might make a difference.

[staceyburke]

Over the years I have had at least 10 different O2 concentrators. I can’t say it has any smell I noticed but the tubbing does. Maybe that is what you are smelling.

I would think a brand new machine would be more apt to have the problem than one that has run for many hours.

All a Concentrator does is take out other gasses not add anything.

[LindanHotAir]

4400 hours on an oxygen concentrator is about 6 months normal use.  There should be nothing in the machine to create a smell as it is a compressor and a bunch of ceramic beads in tubes to separate out nitrogen molecules. As others have mentioned, the tubing is the most likely source of odor as it will release plasticizer (the component that makes plastic flexible) until it hardens and needs replacement.

[Helena]

Sometimes the DME brings refurbished machines that have been cleaned with something that smells of artificial fragrances and very stinky cleaning solutions. I have never been able to get the smell out of the plastic housing. I was able to get those exchanged.

If plastic tubes, and all the bits and pieces are stored where "air fresheners" are used, or with things that have been cleaned with the usual cleaning solutions, all the plastic absorbs those smells.

I send back, or toss things, that have been stored where they collect the chemical molecules from cleaning and fragrance solutions.

Sometimes, the things that come from the DME smell as though they have been stored in the house of a cigarette smoker.

The machines we have now are from DeVilbiss, 5-liter concentrators. No smell in the oxygen and very little from the housing that I can detect. (I use no fragrances of any kind for any thing, and have not for many years.). They are not quiet, but we keep them in another room, with the door closed, on carpet. One machine was very loud, as though it needed a new muffler. I did not accept it.

[Sleeprider]

Joeb, the correct therapy for central and complex apnea is an adaptive servo ventilator (ASV). Many of our members have them, and the preferred model is the Resmed Aircurve 10 ASV. ASV works like CPAP providing a base-pressure to keep the airway open against obstructive apnea, and using pressure support, an increase in pressure during inhale, as needed, when needed to ensure you breathe normally. It is adaptive because it works on a breath by breath basis. Your job is to ask your doctor when he is going to arrange for your ASV titration test, so you can start the correct therapy as soon as possible. Many doctors seem reluctant to do this, or are simply unaware of how to treat central apnea. If that is the case for your doctor, you need to get copies of your tests and other records and find a doctor capable and experienced in the treatment of central and complex apnea. The only reason you might not qualify for ASV is if you have severe heart failure with a low left ventricular ejection fraction (LVEF) of less than 45%. If that is not your case, then don't wait. Get this process started.

The oxygen concentrator is a stop-gap measure that should only be used until you are equipped with ASV. You won't need it after that. You should be using a recording oximeter to measure your SpO2 and determine if the concentrator is adequate for your needs. We have a good wiki on oxygen bleeds that may help you understand it better. http://www.apneaboard.com/wiki/index.php..._with_CPAP

[joeb]

Thanks! This was my first posting to the ApneaBoard. I’m appreciative of the responsiveness, expertise, and concern of the members who have posted to assist me. The responders were correct in their guidance, and it's helped me through this issue.  The malodorous smell probably comes from the 15 feet of standard green oxygen supply tubing.

By now, I am on my fourth oxygen concentrator machine in two weeks. 

Even so, I have no complaints about my Medicare Advantage provider, their insurance benefits, their medical facilities, the sleep doctor who belongs to their organization, or the DME who I am required to patronize if I wish to receive my Medicare benefits. 

The first two rental machines were replaced because they were too noisy and they both had a bad, masking, odor that came from the equipment-ventilation system. Additionally, I suspected that the two machines each tainted the oxygen supply with a contaminate odor. The third machine was a first-use, relatively quiet, Everflo 1020001. Even though it was not the “Q” model, it was attractive, light weight, and quiet in comparison to the two aged concentrators that were previously delivered to me.  

I was happy to have the Everflo ... until two days later when it failed to power-up.

The DME delivered the fourth machine the following day.  It’s a first-use, Invacare Perfector2 V.  It’s not as quiet as the Everflo, but the technician who delivered it told me it’s well-built and reliable. It has now been in operation for one week, and I’m pleased with it.

During the preceding process, I conducted a few ad-hoc tests that relate to my posting.

My observations:

• Green oxygen tubing (od=6mm, id=4 mm) seems to considerably restrict the flow of low-pressure air. As expected, the restriction seems to be proportional to the length of the tubing.
  
• By smelling, I tested four 10 inch lengths of tubing for odor. (1: standard green, 2: black rubber, 3: polyethylene, and 4: cannula).  Each of the four seemed to have a perceivable, unique smell. To me, the standard green o2 tubing was the most offensive.  It seemed capable of giving me a headache and of irritating my nasal passages and eyes.  I don’t use a cannula.  If I did use a cannula, I probably would have rated it as the most offensive.
  
• I also tested a 15’ and a 25’ length of the green o2 tubing.  Surprisingly, I could not discern a difference of intensity of smell amongst 10”, 15’ and 25’ lengths.
  
• The smell seems to be stronger when concentrated oxygen (rather than ambient air) is flowing through the tube.
  

 
My Conclusions and Results:

• It’s important that respiratory equipment that is used many hours per day should not introduce unwanted odors or materials into the respiratory system. So, I prefer to use only brand-new equipment or used equipment that has a verifiable history of ownership and maintenance.
  
• I now don't suspect that the odor is that of ozone. I've learned that ozone may be generated in the presence of electric discharge, but its not generated in the process of pressurizing air and forcing it through a filter medium.
  
• Because the smell of standard oxygen tubing is offensive to me, I obtained 15 feet of Medical Grade, Platinum Catalyst-Cured Silicone Tubing from ColdAndColder. It is food-safe and medical-safe. I sterilized it with boiling water.
  Silicone is purportedly more inert than thermoplastic material. The tubing is ¼” id, and it fits (loosely) over the fittings at both the concentrator’s output filling and at the CPAP machine’s oxygen bleeder-tee fitting. The connection is secured with stainless steel hose clamps.  The smell that was previously irritating me is not discernible when the silicone tubing replaces the green tubing. (BTW, cannulas are available in a silicone version).
  
• I have a variety of symptoms that disturb my sleep and contribute to my discomfort.  In particular, have bradycardia and tachycardia that are independent of sleep apnea. I’m also recovering from surgery to repair a ruptured quadriceps tendon, and I need to wear a hinged brace at night that is very uncomfortable and that provokes obstructive apnea.  As a result, it difficult to for me to form objective conclusions related to a single variable in my treatment. 
  That being said: I’m provisionally encouraged from the result of the use of the silicone tubing.The first night I used the silicone tubing, my overall respiration comfort was greatly improved. However, the pain in my knee kept me restless during the night, and my AHI was high.  Last night, the second night of using the silicone tubing, my leg was not hurting, and it was the best night of sleep and lowest AHI I’ve had since I started CPAP treatment last July, 2021.  
  

I am not inclined to go back to using green oxygen supply tubing between my O2 concentrator and my CPAP machine.

[SarcasticDave94]

Any info on when you get over to ASV therapy? Oh yes, and did you get your copy of your detailed diagnosic sleep study? That is something you really need to get for your records and you could post a redacted version here for us to point out what's shown. Key items like event count and type are important when discussing Central Apnea. If they don't want you to get your report, repeat this: HIPAA law permits you to request and receive it.

I'm not too surprised by the oxygen concentrator to fix CA when the ASV will do a better job. These sleep pulmonary doctors don't really get it right very much. Charlie Brown hasn't got anything on these silly doctors.

Also the problem with using the oxygen concentrator to fix CA is that you're not breathing anything during a CA so the oxygen levels aren't actually going up like they think it will. ASV will make you breathe during a CA because the ASV has a backup rate that gets triggered if CA drops your breath rate, not so the oxygen concentrator.

Bonus, you don't need to smell the concentrator hoses.

Call Dr. Dolittle's office. Request your report. Show us the redacted version. We'll confirm ASV necessity. Call doc again, "My Central Apnea should be treated with a ResMed AirCurve 10 ASV. Let's get me one ASAP."

[joeb]

I'm interested in pursuing the topic that several members have mentioned here; namely, Treatment of Central Sleep Apnea; Supplemental O2 vs ASV.

Is there an existing thread that might be more appropriate than this one?

-joe-