Central Detection Driving Me Nuts!!

[jcr159]

The pulses start at 3 seconds into a breathing cessation, well before an apnea, which requires 10 seconds.  It affects you all night long, even if your AHI would have been under 5, and thus would never have impacted oxygen saturation.

That means that FOTs could wake you up 5 times an hour, even though your O2 saturation would never go below normal.  And if you have breathing cessations that are more than 3 seconds and less than 10, it could disrupt your sleep all night long and never improve your oxygen saturation.

I've already explained why the studies support my theory.  I'm not the only one who finds that FOTs impact AHI.  The studies show the same result with larger populations.  There's only two ways that can happen:  Either the FOTs are splinting the airway, which seems very unlikely given their size, or they're disrupting sleep architecture.  Since the whole point of CPAP is to STOP the disruption of sleep architecture, FOTs may very well be counterproductive - even if the user doesn't actually notice them.

Hey Reznik,

Any updates?  New user, and I'm having issues as well...  apparently I breathe so slowly that I immediately get the FOT pulses when starting up, and ongoing. The slow transitions from inspiration to expiration take so long that the machine thinks I'm having an apnea.  I get this even while breathing and watching TV...

I just changed to 45 minute ramp (max) with the AirSense 10 Auto.  We'll try tonight, but I can't even get to sleep for the most part with my current setup.  

I can PM if this communication should be offline...  Wondering how you handled changing machines from an insurance/DME supplier perspective also...  Did you need to go through your Primary Care Provider to get a different type of prescription?

Thanks!

[Reznik]

The only update is that I continue to use an AirCurve 10 VAUTO with Easy-Breath turned OFF, and so I don't get the pulses.  

I also purchased an AirStart 10 CPAP as a backup.  I've also confirmed by testing an Airsense 10 CPAP (not elite, not Autoset) and they do not send pulses.

I've also been told by Fisher Paykel that none of their units, including their auto adjusting SleepStyle units, use FOT pulses.  Instead, they look at breathing waveforms to make adjustments based upon whether the waveform shows obstructions.

Most of my friends who use ResMed products also use drugs to stay asleep, which is not surprising to me.

[Reznik]

And to answer your specific questions:

1.  If you set a 45 minute ramp, you won't get any pulses for 45 minutes.  That should allow you to get to sleep.  I've found that the FOT pulses wake me up sometimes and don't wake me up other times.  But, even when they don't wake me up, they do disrupt my sleep.

I usually have an AHI of about 5-6 nowadays, almost all of which the machine categorizes as hypopnea and which looks to me like CSR when I look at the breathing waveforms.  Interestingly, with FOT on, the machine categorizes the CSR as apneas, but with FOT off the machine categorizes the CSR as hypopneas.  It appears that the machine's FOT pulses drown out its ability to detect my smaller breaths, causing the machine to think its seeing apneas even though there is a small breath showing on the graph.

That means that with FOT on, the machine disrupts my sleep 5 to 6 times per hour.  I end up feeling terrible in the morning - if I don't wake up a bunch of times.  When I turn FOT off, I sleep much better and feel rested in the morning as long as I can sleep for 6 hours.

2.  I purchased the AirCurve 10 VAUTO at 15% off the advertised price from one of the online suppliers.  It was around $1,400, and I paid out of pocket.  I also purchased the AirStart 10 CPAP for about $350 using my own money from another supplier (there's only one supplier selling that unit) to use as a backup and when travelling.  

I recently qualified for a new CPAP from my health insurance provider and so I insisted that the DME order the AirSense 10 CPAP.  I tested it and found that it makes a fairly loud whine that transmits up the hose into my head.  My research suggests that this happens more often with ResMed machines than it should.  I'm working on exchanging it now.

Of the above, the only machine that gives you the ability to download full data is the AirCurve 10 VAUTO.  The other two give you limited data, and only on the screen.  The AirStart only gives you the amount of time you sleep.  There's no AHI data whatsoever.  The AirSense 10 CPAP gives you an AHI as well.

If I had it to do all over again, I'd probably just insist that my DME give me the Fisher Paykel SleepStyle from the get go.

3.  You do not need a different type of prescription.  Because Bi-level machines can be configured in CPAP mode, any CPAP prescription will generally let you buy any machine online, including the AirCurve 10 VAUTO.

[jcr159]

And to answer your specific questions:

1.  If you set a 45 minute ramp, you won't get any pulses for 45 minutes.  That should allow you to get to sleep.  I've found that the FOT pulses wake me up sometimes and don't wake me up other times.  But, even when they don't wake me up, they do disrupt my sleep.

I usually have an AHI of about 5-6 nowadays, almost all of which the machine categorizes as hypopnea and which looks to me like CSR when I look at the breathing waveforms.  Interestingly, with FOT on, the machine categorizes the CSR as apneas, but with FOT off the machine categorizes the CSR as hypopneas.  It appears that the machine's FOT pulses drown out its ability to detect my smaller breaths, causing the machine to think its seeing apneas even though there is a small breath showing on the graph.

That means that with FOT on, the machine disrupts my sleep 5 to 6 times per hour.  I end up feeling terrible in the morning - if I don't wake up a bunch of times.  When I turn FOT off, I sleep much better and feel rested in the morning as long as I can sleep for 6 hours.

2.  I purchased the AirCurve 10 VAUTO at 15% off the advertised price from one of the online suppliers.  It was around $1,400, and I paid out of pocket.  I also purchased the AirStart 10 CPAP for about $350 using my own money from another supplier (there's only one supplier selling that unit) to use as a backup and when travelling.  

I recently qualified for a new CPAP from my health insurance provider and so I insisted that the DME order the AirSense 10 CPAP.  I tested it and found that it makes a fairly loud whine that transmits up the hose into my head.  My research suggests that this happens more often with ResMed machines than it should.  I'm working on exchanging it now.

Of the above, the only machine that gives you the ability to download full data is the AirCurve 10 VAUTO.  The other two give you limited data, and only on the screen.  The AirStart only gives you the amount of time you sleep.  There's no AHI data whatsoever.  The AirSense 10 CPAP gives you an AHI as well.

If I had it to do all over again, I'd probably just insist that my DME give me the Fisher Paykel SleepStyle from the get go.

3.  You do not need a different type of prescription.  Because Bi-level machines can be configured in CPAP mode, any CPAP prescription will generally let you buy any machine online, including the AirCurve 10 VAUTO.

Thanks for all the info Rez!  Since I'm still in the first month, I'm wondering if my DME would let me exchange for another machine...  probably not, but worth asking.

Do you have any thoughts on going to one of the ASV type machines?  I don't even know what the differences are, but I'd assume they are the "best" solution as they are more capable/advanced?  Or is it just a matter of wrong tool for the job?  My understanding was that the more expensive/advanced machines just did more than the CPAP/APAP, but potentially could handle those needs well.  Looking at Philips marketing materials shows that you keep moving up the line toward the ASV machine based on treatment needs, but interestingly also in the case where the previous tier treatment "isn't well tolerated".  I'd say sleep deprivation like I'm getting vs. no treatment is the definition of not well tolerated.  and its not the pressure, mask, etc...  it's the damn pulses that happen all the time/randomly that interrupt me...

Thanks again!

[Reznik]

Your DME probably won't be aware of the FOT issue.  Most of the DMEs that I've spoken with incorrectly believe that FOTs are only used in Autoset mode.  However, if you're within 30 days, they may well let you switch to another machine in the same category or cheaper.  So, if you have an Autoset or Elite, they'll probably let you switch to a F&P SleepStyle, or to an Airsense 10 CPAP model.  For the latter, you'll probably have to ask them to special order it.

ASV machines are bi-level machines that adjust the pressure on a breath-by-breath basis.  Unlike an autoset machine, they will adjust the pressure as you inhale.  So, if it detects that this particular inhalation is shallow, or non-existent, it will ramp up the pressure until you take a full breath.  Then it will return to baseline and watch for your next breath.  

A regular bilevel in autoset mode will only make adjustments after the fact, i.e., if you stop breathing or have a shallow breath, it will use FOTs to try to determine whether you're having a central or obstructive apnea, and then if it thinks your apnea is obstructive, once you start breathing again, it will increase the pressure going forward.  For this reason, ASV are a completely different animal than a CPAP or BiPap.

ASV machines are horrendously expensive, and there's no justification for the expense because the hardware inside them appears to be exactly the same.  ASV machines look the same, have the same dimensions, and even weight exactly the same as Resmed's CPAP and Bi-level machines.  The difference in how they operate appears to be entirely software based.  (This is also true for Resmed's CPAP vs. Bilevel machines - same hardware but different software).  Because they are so expensive, insurance won't cover them unless you try and fail with CPAP and BiPAP and you meet other criteria, e.g., lots of central apneas or possibly CSR.

My understanding is that there is no evidence that ASV machines produce better outcomes, i.e. longer lifespan, and there is some evidence that they increase the death rate in people with certain heart conditions.  This suggests that ASV may increase the burden on your heart.  The assumption is that those people that couldn't bear the additional burden, because of their heart condition, died.  I would avoid them until more data is available, even if my doctor prescribed one.  I'm concerned that longer term studies may show more risks.  There are people on this board who LOVE their ASV machines.  But, that was also probably true with the small percentage of people who died using them that wouldn't have.

[ChristianH]

Hi, 

Thank you for your post, I thought I was the only one having this problem.

After getting a new cpap machine, a year ago, I suddenly couldn't get a good nights rest. This is after sleeping great with a machine without central detection. Embarrassingly, it took me about a year to connect the dots. Now that the problem is identified I need to purchase a cpap without central detection.

I read that you have seen "brick" cpaps without central detection from ResMed and Respironics. I have had trouble identifying cpap machines without central detection, if you have any information on how to find a machine without central detections please help me out. I am looking to buy out of pocket as soon as possible. 

Thanks.