I am a patient with obstructive sleep apnea (OSA), idiopathic central sleep apnea (ICSA), and complex apnea, which precludes using a CPAP because of the increase in central apneas. I have not had the opportunity yet to try an adaptive machine. I currently use a mandibular device and oxygen to help control my OSA and a pulse oximeter to monitor the oxygen saturation in my blood and pulse, which shows nightly periodic heavy clusters of apparent arousals. My question is whether there is a testing device I could use at home on a regular basis to differentiate between obstructive apneas and central apneas so I could test oxygen titration or possibly the effect of acetazolamide or theophylline on my central apneas? Thank you.
I am struck by all the efforts you are making, yet I can’t help but wonder why you have not tried ASV therapy. Suffering both idiopathic central sleep apnea and presumably complex sleep apnea, I am very curious to know whether there are barriers to your attempting the ASV device in the sleep lab from which you have sought care. We are aware that some sleep labs still seem reluctant to try out the ASV device on their patients for reasons that are not entirely clear. In some cases, the labs may have no experience with the device, or they assume it can simply be prescribed and let it auto-adjust while the patient uses it at home. We believe this approach would be unwise and instead always recommend a full night titration with ASV for someone who has already qualified for the CSA or CompSA diagnosis. We have published a paper describing a brief algorithm that can be used to facilitate the ASV titration in the lab.
We also know that some physicians and patients are very concerned about the pricing of the ASV device, although with insurance coverage the price is quite reasonable. Moreover, many of the DMEs will only lease the device instead of the usual buy-out, because they do not want their patients to fall into the situation of needing to replace a device should it fail. Thus, the lease is the fail-safe backup plan. The monthly lease rate for an ASV device might be as high as $100 or $150 in our area, but given the costs to replace a device if it must be replaced is well worth the investment in the lease. On the other hand, if you just want to purchase an ASV out of pocket, then you can find great deals at www.secondwindcpap.com. I have regularly seen older and newer ASV devices listed on that site at $1,500 or less. Again, be sure to arrange for an in-lab titration with the ASV device before using it at home.
Now, moving on to your specific questions, regarding the best way to titrate oxygen as a treatment for centrals while using oral appliance therapy (presumably mandibular advancement device)? No surprise, again in the lab is the best bet. Not trying to be too lab-centric here, but it would be wiser to start with a titration in the lab, because then you would have much greater clarity about any fine-tuning efforts you wish to attempt on your own. Moreover, for the CompSA part of your diagnosis, there would be no centrals related to that pathophysiological process as you are not on a PAP device. However, you also mentioned idiopathic central apneas, so the lab would also prove clarifying to test you to find out what impact if any OAT has on your overall sleep breathing problems. It would not be unusual for oral appliance therapy (OAT) to have some beneficial impact, given that some central apneas may truly be mixed apneas with an obstructive component.
Should we assume you have already completed a test in the lab with the dental device and oxygen, which showed residual central apneas? If so, what was the recommendation for further titrations of the supplemental oxygen? As you can tell I’m somewhat puzzled by the background you are presenting, and since you are not my patient, I can only speculate on the possible scenarios that may relate to your case. Same thing goes for the medications you noted for treating central sleep apnea; you must obviously work with your sleep physician or other prescribing doctor to determine whether these meds would provide any relief.
Now, having left your most pressing question for last, what are the realistic possibilities for you to monitor some of this complexity at home without having to return to the lab repeatedly? There’s actually a simple yet expensive answer. If you wanted to purchase a home monitoring device such as those offered by Resmed or Respironics, you will notice in the specifications that each device can be fitted to record respiratory effort, therefore, in theory and in practice “central apneas” could be scored on any given night of use. However, I do not know anything about manufacturer restrictions, if any, on the sale of this equipment to patients. Another and probably more optimal solution is to find a sleep center that already owns one or more of these devices, and then negotiate a way to rent the equipment for various periods of time. Then again, if you are hoping to monitor your sleep breathing at home for an extended period before trying ASV therapy, then it may make more sense to buy the portable device for yourself. Last, given all the chaos in the field of sleep medicine now, I would not be surprised if you found a used portable device, but I am uncertain how to go about finding one and do not know of any pricing info.
Good luck in your efforts.