Pressure Settings

Could someone please explain this a little more?

Obstructive Apnea (OA)

A good rule of thumb is to keep your minimum pressure setting about 2-cm below your 90% pressure or near the average if they are close. The goal is to raise support (Min Pressure / IPAP) to reduce/minimize/if we are lucky, eliminate Obstructive events. These include Hyponeas, Flow Limits, and Snores. The Max Pressure / EPAP is lowered to minimize other issues (Aerophagia , swallow too much air, too much pressure causes wakeups) if needed. Typically it is set at either MAX pressure (20 cmH2O) or just above the max pressure to prevent wild running high.

Where did you get the idea that the 90% number is your guiding number for anything?

I got it from here Sir:

http://www.apneaboard.com/wiki/index.ph ... a_.28OA.29

Ahhh....that works sometimes but not all the time. It's not the gospel by any means.
If it was then I would need to use a minimum pressure of 14 or 15 instead of 7. My OSA is worse in REM...much worse and needs a LOT more pressure to keep the airway open. REM amounts to 20 % of the night. I don't want to use mid teen pressures for the other 80% of the night stuff when there's no need. I have seen 90% pressures upwards of 17 or 18 in the past....just because of the REM pressure needs.

90/95 % numbers are easily skewed to the high side by relatively short periods of time at the higher pressures so it's not always a good guide line for a minimum number starting pressure. Now it can be for some people when their pressures don't need to go very much higher for REM or supine sleeping pressure needs but it's not necessarily the gospel for everyone.

I would be more apt to use the median average pressure as a guide line than I would be a 90% pressure because I know first hand that the 90% pressure doesn't always reflect the bulk of the night pressure needs. It's just too easily skewed.

All the minimum pressure has to be is close enough to what might be needed in special situations (like my REM) so the machine can get to that pressure quickly enough to hold the airway open and prevent airway collapses. There's nothing magical about the 90% number for the majority of people.

I have been experiencing Aerophagia lately and I thought maybe my pressure is too high for moderate OSA. Here is a screenshot form last night.

The severity of a person's OSA has absolutely zero bearing on pressure needs.
I know people with a very mild diagnosis with maybe 10 AHI who need 20 cm pressure and someone with a really severe case of OSA with diagnostic AHI of 80 who might only need 5 or 6 cm to hold the airway open.

The fact you are having aerophagia is most likely pressure related though and I for sure wouldn't be using the 2 below 90% rule with aerophagia in the mixture. It will simply make you end up using higher pressures all night long than you might actually be needing and it's the higher pressure that is causing the aerophagia issues.

We need to find an acceptable minimum and maximum pressure where your OSA is still well treated and we don't invite the aerophagia monster in for a visit.

Your pressures aren't really moving around very much once the ramp time has ended.
I think a reduction in minimum EPAP is worth trying to see if it helps reduce the belly symptoms.

Forget what you read on the other apneaboard forum...the aerophagia issues pretty much force you to go about things differently.

I would like to see how you do with a minimum EPAP of 8.0 cm....all other settings the same and then see what the report looks like as well as a report on how you feel in terms of belly issues.

TCB wrote: ↑

Wed Jan 08, 2020 3:08 pm

Could someone please explain this a little more?

Obstructive Apnea (OA)

A good rule of thumb is to keep your minimum pressure setting about 2-cm below your 90% pressure or near the average if they are close.

I can't explain it, because that was written by someone who doesn't understand what 90% numbers mean, AND who doesn't know how to read a pressure graph.

TCB wrote: ↑

Wed Jan 08, 2020 3:08 pm

The goal is to raise support (Min Pressure / IPAP) to reduce/minimize/if we are lucky, eliminate Obstructive events. These include Hyponeas, Flow Limits, and Snores. The Max Pressure / EPAP is lowered to minimize other issues (Aerophagia , swallow too much air, too much pressure causes wakeups) if needed. Typically it is set at either MAX pressure (20 cmH2O) or just above the max pressure to prevent wild running high.

That part isn't horseshit.

Here is my graft after pressure changes:

How's the aerophagia?

You can omit the snore graph the next time so that the other graphs can be a bit larger and more easy to see.
The snores are shown on the Events graph if they happen so there is no need for the snore graph since it isn't showing anything anyway.

How did you sleep last night?

Slept pretty good, although I usually have a little brain fog in the morning. Thanks for the advice on the graph.

I see 3 breaks in therapy after the 22:30 ish bedtime. Why? We know you were awake then.

Some of the flagged events might not be real asleep events since we know you were awake at least 3 times.

How's the aerophagia?

The 1st break was my kitty woke me, second was to pee, and the third was to take a thyroid pill. Kitty waking me doesn't always happen, but the other two do every night. The aerophagia was almost non existent!

When you have time you might review the videos here and see if you can learn how to spot awake/arousal related flagged events vs asleep flagged events.
Only asleep flagged events really count in the AHI evaluation process and sometimes the machine can mistakenly flag awake/arousal related breathing irregularities as some sort of apnea event.
http://freecpapadvice.com/sleepyhead-free-software
Remember the machine doesn't have a clue if we are asleep or not. It only measures air flow and our awake/arousal related breathing is very irregular when compared to awake breathing. False positive flagging can and does happen.

At this point I would suggest just running with this new setting for a few more days and see how you do with it.
The CAs/Central apneas we can't do much about anyway and if you remove those from your AHI you have a respectable low AHI even if all the flagged events were real (but I suspect a few aren't real).

Sometimes we have to make compromises when it comes to using pressures that cause aerophagia. We don't want to be miserable during the day or sleep poorly during the night because of aerophagia just to get the AHI reduced maybe 1 point. Just not worth it IMHO.

Thanks!!! I'll review all the videos and post another graph in a couple of days after keeping all the same settings.