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+--- Thread: Traded OSAs for CAs during home APAP trial - What next ? (/Thread-Traded-OSAs-for-CAs-during-home-APAP-trial-What-next)
Traded OSAs for CAs during home APAP trial - What next ? - Stom - 07-04-2018
I'm home trialling a Resmed Airsense 10 with Oximeter after a Kaiser take home WatchPat study confirmed moderate/severe sleep apnea. Results of the trial are not restful so far 5 nights in. CAs per hour: range from about 4-19. Sleepyhead data shows low to no OSAs per hour, generally low mask leakage and flow restrictions but lots of CA events (maybe periodic breathing at times?).
What kinds of things should I be asking my doctor when they review the home titration results with me?
I've skimmed Trajectories of Emergent Central Sleep Apnea During CPAP Therapy by Dongquan Liu et al that found:
Quote:"The proportion of patients with CSA in week 1 or week 13 was 3.5%; of these, CSA was transient, persistent, or emergent in 55.1%, 25.2%, and 19.7%, respectively. Patients with vs without treatment-emergent CSA were older, had higher residual apnea-hypopnea index and CAI at week 13, and more leaks (all P < .001). Patients with any treatment-emergent CSA were at higher risk of therapy termination vs those who did not develop CSA (all P < .001). "
So it seems like it will take months to see which direction the CAs will go. With no DME coverage, I'm kind of reluctant to buy an APAP out of pocket, especially if its making things worse and I can't just easily sell it on if the CAs persist and I need different treatment options.
Suggestions?
11 year-old split night study (did not lead to trying a PAP)
Without PAP:
RDI: 15.3 (based on short sleep with 17 Central and 23 Obstructive)
During short attempt at CPAP titration:
RDI: 41.4 (28 Central (longest 49.6) and 12 Obstructive (longest 108 seconds), min O2 Sat 68.8 )
New Kaiser take home WatchPat
Apnea Hypopnea Index (AHI): 22
Respiratory Disturbance Index (RDI): 34
Oxygen level: Normal
(They tell me no centrals, but I haven't seen the print out.)
Kaiser set the APAP to:
7-20
EPR On, set to 3
In-line AB filter with AB filter setting on
No humidifier (for infection control reasons)
P10, N20 and F20 masks
RE: Traded OSAs for CAs during home APAP trial - What next ? - jaswilliams - 07-05-2018
Your going to need a different machine most likely an ASV with that level of CA's
RE: Traded OSAs for CAs during home APAP trial - What next ? - DeepBreathing - 07-05-2018
G'day Stom. Welcome to Aponea Board.
Looking at your earlier sleep study you've obviously had some amount of central apnea for a while. The WatchPAT test doesn't necessarily differentiate between central and obstructive apneas - depends on which version of WatchPAT you used. AFAIK you need this model to detect central apnea: https://www.itamar-medical.com/watchpat-central-plus/
So your centrals may be idiopathc, not treatment-emergent. It would be good to know for sure what the WatchPAT showed up.
The clusters which appear in your charts charts at first glance look like obstructive apnea, so it would be good if you could zoom in so you get maybe five minutes worth of flow, just to be sure. Although the machine is pretty good at diagnosing, it's not infallible.
Assuming they are, in fact, central apneas then we need to adjust your settings to minimise them without leaving you open to obstructive apnea and hypopnea. I'd suggest you turn the EPR off as a first step, and see how that goes for a few nights. If there is some improvement, then we might try adjusting the pressure as well. If neither of these steps work, then you might need to consider an ASV machine, which is expensive and you will need to jump through hoops to get it.
RE: Traded OSAs for CAs during home APAP trial - What next ? - Stom - 07-05-2018
Thanks :-)
I was a little surprised that any of the WatchPats could distinguish OAs from CAs. The snore/body position sensor had the little heart on it IIRC, which I think means was the the newer model, but I don't know for sure - I relied on Kaiser to know their business, and still am hoping that is the case. But, OTOH, even after I showed them the old titriation study results with apneas up to 108 seconds on PAP, they *still* sent me home alone with an APAP for a week of auto titration and they haven't replied to my inquiry about whether I should continue or if the settings should be changed. Seems like someone should probably keep in an eye on the in progress home trial data rather than just wait until the end. I had hoped to ask them about reducing/eliminating the EPR since I've seen that mentioned in the forum relative to CAs, and because the titration pressures have stayed pretty low. I'm reluctant to alter the clinical menu during their titration trial, though it seems like it would be a good thing to try :-/ I had to ask for the Oximeter to be added so I could make sure I wasn't desaturating overnight night (so far so good, nothing below 84, and the average is all above 90.)
I had hoped the CA range was within the treatment induced range. A look back at the big data study of induced CAs seems to show the average levels of treatment-induced CAs are lower than my Sleepyhead data for the AirSense10 - not that I understand the study at more than a superficial level after researching here and on the web over the last week.
Here some additional screen shots, including a 5 minute view of that same cluster, and a wide view of my best night:
RE: Traded OSAs for CAs during home APAP trial - What next ? - jaswilliams - 07-05-2018
The second an third CA's and beyond from the cluster are real and not obstructive you are going to need to jump through hoops to get the correct treatment CA numbers can be very variable and change from night to night with no change in therapy settings.
RE: Traded OSAs for CAs during home APAP trial - What next ? - Stom - 07-05-2018
Thanks for the input.
The Friday meeting with the RT should be interesting. They only will have looked at the cellular data, not the 25Hz sampled data on the SD card. But it sounds like just the CA event index should be enough info for them to question the suitability APAP.
RE: Traded OSAs for CAs during home APAP trial - What next ? - Sleeprider - 07-05-2018
Strom, I think you may see a significant improvement in CA if you will reduce your EPR to 1 or off. EPR is surprisingly efficient at causing CA events in treatment emergent individuals. I don't promise that you will not see some CA, but I can pretty well assure you the event rate will be less than half if you will eliminate the EPR. You have virtually no obstructive events, so along with turning off EPR you can reduce your pressure. I would recommend a pressure of 7.0 fixed with no EPR and then see where that takes you.
RE: Traded OSAs for CAs during home APAP trial - What next ? - Stom - 07-05-2018
(07-05-2018, 08:55 AM)Sleeprider Wrote: Strom, I think you may see a significant improvement in CA if you will reduce your EPR to 1 or off. EPR is surprisingly efficient at causing CA events in treatment emergent individuals. I don't promise that you will not see some CA, but I can pretty well assure you the event rate will be less than half if you will eliminate the EPR. You have virtually no obstructive events, so along with turning off EPR you can reduce your pressure. I would recommend a pressure of 7.0 fixed with no EPR and then see where that takes you.
Thank you. This sort of thing seems perfect for simple experimentation, though I do know that a sample size of n=1 means it can be harder to tell causation from coincidence, especially if the hourly CAs are variable night to night. I currently have the sleep lab's loaner, which they are supposed to be monitoring and I only have a night left before the consult. Although I could wildcat it and change the EPR tonight, I expect that wouldn't really give me enough to go on either way without more nights to demonstrate a trend rather than just possible regular variability..
Do you know of any published studies that have found a link between EPR and CAs? I found reference on the board to a study mask leaks and CAs (could they be related, since they both affect pressure?) I'm looking arm myself with verifiable info, possibly with a mind to them loaning the unit for another week on them with different settings. I don't want them to just throw me on APAP of my own, have it fail, then throw an ASV (each with 100% co pay bill) at me. It even seems like they should do something a bit more carefully considered and methodical. Maybe redo the sleep study, or something?
Cheers :-)
RE: Traded OSAs for CAs during home APAP trial - What next ? - Sleeprider - 07-06-2018
I guess I need to do a technical report on the correlation of pressure support (EPR) to CA. While it varies between individuals, I can assure you that it is a very strong correlation. Where it gets a little odd is that some people show CA with relatively low pressure support, while others may require more than 6-cm of pressure support to trigger CA. At some point, I'm pretty sure I can cause CA in almost anyone once we find the level of pressure support that causes the events. The mechanism is very simple. When pressure support (difference between IPAP and EPAP) is applied, ventilation rates are increased. This lowers CO2 in the blood stream (hypocapnia) and affects respiratory drive. Again, the effect differs among individuals, but the use of pressure support in non-invasive ventilation and invasive ventilation to affect CO2 is a very basic principle.
Our CPAPs are ventilators, and when we introduce EPR, we are using bilevel positive air pressures with different inhale and exhale pressures, i.e. pressure support. Even though the Airsense 10 pressure support is limited to 3-cm, in sensitive individuals, this can create hypocapnia and induce centrals. A few individuals may experience the onset of complex apnea with just fixed simple CPAP pressure with no pressure support, but as pressure support is added to therapy, the chances of triggering complex apnea becomes considerable greater in sensitive individuals. Treatment emergent complex apnea may reconcile as the individual adapts, but in others, a more sophisticated therapy (ASV) may be required to treat both the obstructive and central apnea. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3700705/
I hope this helps explain some of the thought behind the suggestion to reduce or eliminate EPR. Again, the limited pressure support of Resmed EPR is tolerated by the majority of users as a comfort feature, but in a select, lucky few, there is a higher likelihood of inducing central apnea and periodic breathing.
RE: Traded OSAs for CAs during home APAP trial - What next ? - ShaunBlake - 07-06-2018
(07-06-2018, 08:47 AM)Sleeprider Wrote: I guess I need to do a technical report on the correlation of pressure support (EPR) to CA.
<snip>
… Treatment emergent complex apnea may reconcile as the individual adapts, but in others, a more sophisticated therapy (ASV) may be required to treat both the obstructive and central apnea. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3700705/
<snip>
That's a good an excellent guess! In fact, if you were to guess that you need to do technical reports on each of the components involved in OSA, you would be "spot on" as the upside-down folk and their "Hinklish" progenitors say. (Well, in my (perhaps not-so-humble) opinion.)
And thank you for the NIH article (which you very clearly and concisely summarized) – very informative!