Home Sleep Study - Low AHI but significant desat

[Sleeprider]

The question is whether the request for bilevel was actually submitted to insurance for denial, or if this was preemptive by the DME. My guess is that it's the latter. They don't want to go through the effort unless there is certainty. As far as I know, Insurance does not have an AHI threshold for bilevel. The determination that bilevel therapy is necessary and beneficial is made by the doctor. The DME's job is to submit the claim. Ask them to "show me the denial", because I did not see a claim denied.

[SarcasticDave94]

Yep, make the DME work. They're probably being lazy. It also sounds pretty fabricated.

PS you can try calling your insurance customer service, asking about a recent supposed CPAP type machine denial from X the DME.

On supplemental oxygen, you should be able to add it to any CPAP via either the Oxygen bib built-in into the hose, or an oxygen insert that goes on the mask end of the hose.

[ArcherNeedsSleep]

I have no patience...I grabbed a copy of my prescription from my doc and ordered the AirCurve on my own.  


I'm still letting the doc and the insurance fight it out, and if they want an in-lab sleep study, I'll probably do it just to get an "official" diagnosis of sleep apnea so I don't have to keep doing this out of my own pocket.  However, I found a reasonable cost AirCurve and decided it was better to solve my SpO2 issues quickly for my own sanity.

With that said, the machine arrives today (yay!), and I wanted to ask a clarifying question about the settings that were recommended earlier in the thread.  
Specifically, it's about the EPAP min of 8.  Is that going to feel like an 8 on my original machine, or will it feel like a higher value because of the better response of the new machine?  

I'm asking because I've pushed my min up to 9.6 based on the feeling of not getting enough air at lower settings.  It's probably an altitude thing, because I end up lowering it when I travel to sea level.  But at my house, it needs to be at least 9.6 or I start to feel air-starved and can't sleep.

So, should I try the 8 on the AirCurve, assuming that it will be enough air movement, or should I default to the 9.6 setting that I'm using on my existing machine?

[Sleeprider]

I don't normally do this, but I'm going to start by quoting myself, because this is the basis of how we want to proceed.

It's been almost 3-years since this thread showed up. With your persistently low SpO2 saturation, you should seek professional diagnostics and supplemental oxygen. Your SpO2 saturation has dropped from a median of about 93 to under 90 in this most recent chart (the median SpO2 statistic is cutoff).  What's important is the period of time below 88%, which is the threshold for Medicare and most insurance, and you have quite a lot.  I don't know if your low SpO2 is all the time, or only as you sleep. It's likely you will need to wear a medical grade monitor to make that determination, but assuming this is strictly nocturnal, that would make a stationary (non-portable) oxygen concentrator a more likely choice.  

Before we go that route, I think you have another option. Your oxygen levels were better three years ago. Your tidal volume and minute vent was also higher then and you did not show an inverse inspiration/expiration time ratio. Based on what I'm seeing here, the easiest solution for you will be to request a prescription for bilevel PAP like the Resmed Aircurve 10 Vauto. The objective with the Vauto would be to improve on tidal volume by using pressure support to overcome all residual flow limitation and provide a mechanical assist your good spontaneous respiratory efforts.

Bilevel is easier to titrate to improve SpO2 and respiratory volume.  Basically, we elevate the minimum EPAP upwards to increase the positive end expiratory pressure (PEEP), which with mechanical ventilation helps to recruit more lung volume and increase the partial pressure of oxygen to promote better gas exchange in the lungs.  Secondly, the pressure support is used to improve ventilation, resolve flow limitation, RERA, hypopnea and upper airway resistance.  The Vauto also has an adjustable trigger sensitivity which we can leverage to limit or eliminate the CA events from that improved ventilation. Your current statistics show your inspiration time exceeds expiration time. This is consistent with inspiratory flow limitation and is also resolved with higher bilevel pressure support.

You went with the out-of-pocket option we discussed in that post, and sometimes that is the best option. I'm certain your DME obstructed your acquisition and that insurnace would have paid. With this purchase you can submit an out-of-network claim and move on.

The basics are, we use EPAP for controlling obstructive apnea and keep the airway stable. Pressure support or IPAP are used to mechanically assist getting a full breath, eliminating flow limitation, RERA, snores and hypopnea. So the first task is to identify that minimum EPAP pressure that will resolve OA events, then use the pressure support for the rest. BUT THERE'S MORE! In addition to keeping the airway patent, EPAP improves oxygenation by recruiting lung volume and establishing the "positive end expiratory pressure" (PEEP). Pressure support is for ventilation and to expel CO2. So in terms of respiration, EPAP and pressure support play in important role in oxygenation.

Although I suggested EPAP min 8.0 previously, we can start lower and observe the results. I expect that you will have a good AHI with lower EPAP, but that we will see an improvement in SpO2 with a higher minimum. The best way to go about this is going to be to start with a lower EPAP and observe your results. We will increase EPAP min to see if SpO2 responds to that. Ultimately, the optimized settings will be based on both efficacy and hitting your SpO2 targets. So with that understanding, let's begin with a relatively low EPAP min of 6.0, PS 4.0 and IPAP max 14.0. We will start with trigger sensitivity on high to address the CA events and consider moving to very-high if needed. I intend to monitor your results and expect to incrementally increase EPAP while getting your feedback on comfort and the charts. We have time on our side to come up with what works, and don't have to worry about an incompetent DME meddling in the process.

[ArcherNeedsSleep]

...Submit my insurance claim and move on..... It's like you know me.    
Yes, I'm impatient AND averse to conflict, so this route is music to my ears.

Thank you for your patience and your explanation of the settings.  I had in my head (totally incorrectly) that the EPAP 8 was like the minimum setting on the APAP machine.  And I know that would be too low for comfort.  But I think I understand better now - it's a subtraction problem based around the pressure support rather than a fixed boundary for the min/max pressures.  And the subtraction is only on my exhale, not on my inhale, so I won't be air starved.  Hopefully I have that more correct now.

I'm comfortable with sticking to your original values.  I'll post results from Oscar as soon as I have some.  Thanks!

[Sleeprider]

Great! I wanted to start at the higher EPAP to address SpO2, and I think your attitude moves us forward faster.

[ArcherNeedsSleep]

First night down.  

I think my brain and body learned a new breathing cadence overnight.  At the beginning of the night, I felt like the inhalation pressure dropped off before I was ready to be done inhaling.  But by the time I woke up in the morning, my breath cycle was pretty well attuned to the machine (or vice/versa, I'm not sure how that works).  We will have some tweaking to do, but it was a good start.

There were a bunch of CAs, which I've grown to expect.  But my flow limits are much better, and my inspiration/expiration times seem to have moved into a semi-normal orientation.

SpO2 was so much better, even without any dialing in.  I dropped from an average of 3.5 hours below 90% to only half an hour last night.   

I've attached Oscar charts.  I did reorder it different from the "standard" because I have a small screen and can't fit many of the sections into a single picture.  (I also remove the leak and snore charts because they are typically zero - I don't have any leak issues at all, so there's no value in that section of the charts.)
If you would prefer the standard order with more screenshots instead of this modified order, please tell me and I'll do it that way instead.

I also added a sample of the flow curve...mostly because I've never seen mine look like the "good" pictures, and I thought it was pretty :-)

Any thoughts or advice are appreciated.

           

[SarcasticDave94]

My bit of info will be short, consider only until better informed like Sleeprider gives his take.

In light of the CA, maybe trigger very high can be trialed. There is a correlation with trigger settings and CA for most.

[ArcherNeedsSleep]

Thank you, SarcasticDave94.  I'll give that a try.  

I would love to lower the CAs for more reasons than just the sleep and O2 saturation - I end up swallowing air when I have CAs, so a night with higher CAs will usually cause a bad stomach ache in the morning.  :-(

[SarcasticDave94]

If used, I'd believe you'd see some effect immediately. However, remember that CA are contrary, consistently inconsistent little buggers.