[Equipment] Advice on ASV machine

[jtrops]

My wife has been diagnosed with mild obstructive sleep apnea.  The clinic wants us to purchase a Resmed Airsense 11, and after doing the math it looks like much of the cost will not be covered by our insurance. 

So, I found a Resmed Aircurve 10 ASV that we could purchase used.  My question is whether, or not, it makes sense to purchase this machine, and work through calibrating it ourselves.  It doesn't look like it has many settings, and it seems like there might be a baseline to start with for a mild case like she has.

Any insights, or help would be greatly appreciated.  If this could work for us it would hopefully get her sleeping better, and save us a good deal of money.

[Sleeprider]

Jtrops, take a look at Supplier #1 for a Resmed Airsense 10 Autoset Card To Cloud model. You can get it new with a 20% discount from the $590 cost using code FALLSAVE for a net cost of $472. The discount also applies to any mask or accessories. If that code does not work, post back and I'll keep you posted of any update.

The Aircurve 10 ASV machine is an amazing device but intended for treatment of central apnea. It has a CPAP mode, but it is fixed pressure and doesn't have some of the features that the Airsense 10 has. How many run-hours on the ASV and what the asking price is. If an adaptive servo ventilator was what she needed, it would be amazing to acquire it for a good price because they are normally very expensive devices. Unfortunately the features that make the ASV suitable for central apnea make it very disruptive to sleep for most OSA patients. If you have any details on the diagnostic study, we could comment further.

[jtrops]

Thank you for your reply. It is good to hear that we may be barking up the wrong tree.

All of the articles that I read say that the ASV machines provide for more natural breathing, and work for OSA as well as CSA. This is the first I've read that it can be disruptive.

It looks like the Aircurve is at least being sold for OSA, CSA, and mixed. It says on their website that it automatically adjusts pressure for OSA events. Is that somehow what disrupts sleep?

[SarcasticDave94]

Agreed with Sleeprider. I've had an ASV before, and for my therapy needs it was great at treating Central Apnea. Because there's a base EPAP pressure, it also will take care of the Obstructive Apnea. When I needed treatment outside the CA scope due to COPD, the ASV became more of a square peg in the round hole.

The disruptive question likely comes from the pressure delivery, especially the pressure support (PS) that adds to EPAP to give the differential blast needed to combat the CA.

Also of note, and I've tried it myself, the ASV CPAP mode is a static single pressure between 4-20. Example if set to 20, it blows 20 until turned off. This makes the ResMed AutoSet Auto CPAP far more comfortable when Exhale Pressure Relief is active. This EPR gives up to 3 cmH2O decrease to allow exhalation easier, and makes it a bilevel in concept.

[Sleeprider]

One of the best references to learn how the different machines work and their intended application is the Resmed Clinical Titration Guide https://document.resmed.com/en-us/docume...er_eng.pdf You can look up the Airsense CPAPs and Aircurve ASV (page 28). It would be extraordinary for any person with mild obstructive sleep apnea, probably mostly hypopnea, to be started on a ventilator rather than CPAP or spontaneous triggered bilevel. The ASV is a ventilator and adjusts pressure support to provide a breath or supplement breath volume when the user does s below the target respiratory rate or volume. For an individual unaccustomed to positive air pressure therapy, this machine will feel like it is in control and forcing breathing. If your condition requires this, it's absolutely a Godsend, but for a person with mild apnea, it is constantly changing pressure. Your wife would have no events, but there are many threads on this forum by people that are self-treating with ASV that fail or have great difficulty adapting to the therapy.

Aside from saving on a used ASV, you have no idea what you are getting into, or more specifically asking your wife to do. What your wife needs is CPAP, most likely at a low pressure with exhale pressure relief to make it more comfortable, improve ventilation and treat flow limitations, respiratory effort related arousals, hypopnea and perhaps apnea. Ask this question concerning the use of ASV of her doctor or the person that diagnosed mild sleep apnea. Consider it a challenge to find any respectable professional that would make that recommendation. I have helped many members obtain ASV and adapt to the therapy when it is appropriate, but this conversation is a good reminder of why these are prescription required devices.

[jtrops]

Thank you for clarifying that for me.  I wasn't questioning the quality of your advice, but as you point out I don't know what we are getting into.  I appreciate the time you put into breaking it down for me. 

I have found a couple of airsense machines in a similar price that I will consider.  I see that some people mention how many hours the machine has been used, and others don't.  My guess is that, like many things with seals that go bad, hours is a good way to tell if a machine is still in good functioning order. 

If we purchase a used machine what should be be looking for?  Or, what should we look out for?

[jtrops]

If you have any details on the diagnostic study, we could comment further.

I have the sleep study report that we received from the sleep clinic.  What details would be helpful?

[Sleeprider]

Resmed machines have a normal motor life of around 22,000 hours. Seals and other internal parts are not generally degraded unless a UV cleaner was used, and some members have installed new motors in old machines to get even more life out of them. In fact, for about $200 a certified repair facility will replace the motor, calibrate the pressure and reset the run hours. Supplier #28. The run hours can be read by turning on the machine, entering the clinical menu by pressing the home button and control dial simultaneously, and scrolling down to the About section. I would do that for any machine just to be sure it powers up. The biggest damage a machine can incur other than physical damage is to be exposed to cigarette smoke. It is very difficult to clear and you should specifically ask if the machine has been in a smoking household.

The sleep study is interesting. I had expected most of the events would be hypopnea, but they are evenly mixed between obstructive apnea and hypopnea. There is quite a bit of movement and I wouldn't be surprised if you had a notation on the study concerning restless legs or something similar. Flow limitation is relatively high through much of the night and is likely where events like apnea and hypopnea arise. Most events are while she is supine. Events also appear in "clusters". This means obstruction is occurring repeatedly and separated by brief arousals. The pattern looks like what we call "Positional Apnea", and we often observe it even in individuals on CPAP or ASV. https://www.apneaboard.com/wiki/index.ph...onal_Apnea This can often be mitigated by avoiding sleeping on your back or avoiding the use of multiple or tall, firm pillows, or sleeping inclined.

Based on the high flow limitations, your wife will do best on a machine that produces a form of bilevel pressure . The Airsense 10 does this with EPR and has up to 3 cm difference between inhale and exhale, and of course the Aircurve 10 VPAP S or Vauto can provide even more pressure support. We use the exhale (EPAP) pressure to hold the airway stable, then an increasing air pressure as inhale proceeds (pressure support) helps to reduce inspiratory effort and flow limitation as air flow increases. The Resmed CPAP is unique in that it really behaves as a bilevel.

Finally, I didn't mean to come down so hard on ASV, it's just very difficult to adapt to a machine that has different pressure on nearly every breath. With ASV we can set PS min and PS max but there needs to be 5-cm between those settings. So if we decide 3 cm of pressure support is the ideal minimum PS to avoid flow limitation and hypopnea, the setting will necessarily be in the range of PS min 3 and PS min 8. That is how we setup an ASV as a bilevel for individuals without central apnea. Some people are very sensitive to the machine producing a different pressure support on each breath, and others tolerate it. We just can't predict who will do best. We do however know that the tolerance for CPAP with EPR or bilevel with fixed pressure support is pretty easily tolerated and titrated.

[jtrops]

Thank you again. This is very helpful. It looks like an Airsense machine is more appropriate from what you're saying. Is there any reason an Airsense 11 is preferred over a 10? Would it be just as good to look for either?

[Nightynite]

The A 10 has a proven track history, and I believe both have the same algorithm. Since the A11 is relatively new it’s hard to say how durable it is. The A10 is awesome! I have a spare as a back up along with a battery power supply. Ya don’t want to be caught with out a working cpap machine.
You will really be scrambling to figure something out.