Unexplained High AHI

[adam5534]

My AHI is quite high, average 13.39, and typically about 10-16. Kaiser doesn't seem to know what to do, and I don't see any obvious correlation between anything like mask leaks or pressure too low or high. Any suggestions please? Thanks, Adam
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[Todzo]

Talk with your doctors about these options:

Gilmartin G, McGeehan B, Vigneault K, Daly RW, Manento M, Weiss JW, Thomas RJ.
Treatment of positive airway pressure treatment-associated respiratory instability with enhanced expiratory rebreathing space (EERS).
Source: J Clin Sleep Med. 2010 Dec 15;6(6):529-38. Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
Link: http://www.ncbi.nlm.nih.gov/pubmed/21206741

Dynamic CO2 therapy in periodic breathing: a modeling study to determine optimal timing and dosage regimes
Yoseph Mebrate, Keith Willson, Charlotte H. Manisty, Resham Baruah, Jamil Mayet, Alun D. Hughes, Kim H. Parker and Darrel P. Francis
J Appl Physiol 107:696-706, 2009. First published 23 July 2009; doi: 10.1152/japplphysiol.90308.2008
Link: http://www.ncbi.nlm.nih.gov/pubmed/19628721

[adam5534]

Thank you very much for your quick response and the references. I will talk to them.
Thanks,
Adam

[porete]

I am not an expert, but you may need to turn your minimum pressure up. It appears your machine is not able to compensate and get to a higher pressure fast enough, thus causing an elevated AHI. If I were you, I would raise the min. to 7, and see if your numbers improve.

[Pugsy]

Your minimum pressure is not high enough to do a good job of preventing the collapse of the airway tissues.
The Obstructive apneas and hyponeas aren't being prevented like they should.
It has to try to play catch up too much. Can't get to where it needs to be to do the best job quickly enough.
A little more minimum pressure (probably around 1.0 cm) would help give the machine a better start.
Or cpap mode around 8.0 or so.

The CAs... How are you sleeping? Waking up a few times during the night?
We don't treat those with more pressure.
Hopefully if the arousals from the too many OAs and Hyponeas are reduced the CAs might reduce also and not be as frequent.

[Wulfman...]

I am not an expert, but you may need to turn your minimum pressure up. It appears your machine is not able to compensate and get to a higher pressure fast enough, thus causing an elevated AHI. If I were you, I would raise the min. to 7, and see if your numbers improve.

Agreed. The leaks are also corresponding to the pressure changes, so "mask fit/adjustment" also seems to be a problem.

Try switching to straight pressure of about 8 or 9 and see if that helps while you figure some of this out. You've got too many variables going on trying to use APAP in a range of pressures and you need to eliminate as many as you can.

Den

.

[adam5534]

Hi,

Your minimum pressure is not high enough to do a good job of preventing the collapse of the airway tissues.

I'll try that.

The CAs... How are you sleeping? Waking up a few times during the night?
We don't treat those with more pressure.
Hopefully if the arousals from the too many OAs and Hyponeas are reduced the CAs might reduce also and not be as frequent.

I don't wake up in the middle of the night, but don't feel as rested as I should in the morning.

I will contact Kaiser and ask to see a Sleep doctor. The med equipment technicians don't seem to know what to do. They keep worrying about the mask leakage, which isn't perfect, but the leakage doesn't seem to correspond with most of the events.

Thanks,
Adam

[Pugsy]

Your leaks aren't real pretty but they are below large leak territory so I don't think we can blame the AHI on leaks.
Your leak number to avoid is around 90 L/min.
They could of course be impacting sleep quality and disturbing your sleep at some level which of course affects the way we feel.

If you decide to give straight cpap a try...don't do cpap mode..instead do APAP mode but make your minimum pressure equal your maximum pressure...that mimics cpap by giving you a fixed pressure and still allows for Flow limitation to be gathered.
In cpap mode we lose Flow limitation scoring.

Regarding leaks and pressure...the machine reports total leak which is mask vent rate plus any excess leak.
When you have an increase in pressure it is also going to increase the vent rate and your leak line will fluctuate as the pressure fluctuates...more pressure equals more vent rate.
So some of what you see the leak line doing is in response to the vent rate increasing and not necessarily pressure causing leaks. May cause some but not all of the ugly you see.