Early Pressure Blast

Most every night, my machine quickly goes to max pressure (20) within an hour. Last night, it blasted me so hard that my AirTouch F20 strapped pretty tightly down leaked so much it woke me up. Only thing I could do was take it off for a minute and the machine stopped. I then put it back on and the rest of the night was fine - with a pretty awesome AHI score to boot. Take a look:


Here's the detail of my first hour:


A few questions for the brain trust:

1. Why is the AS10 blasting me like this EVERY NIGHT?
2. Anything I can do to mitigate this?
3. Any thoughts why my breathing seems to always be shallow the first hour of sleep, then amplifies for the rest of the night?

Thanks!!

The machine is responding to flow limitations during the first part of the night with more pressure. That's what the auto adjusting algorithm is designed to do. Flow limitations (assuming no nasal congestion) are early warning signs that the airway is trying to collapse.
Sometimes the machine's response creates more problems than the FLs themselves create a problem and sometimes we limit the max pressure and just let a few FLs slip past the defenses. Like maybe limit the max to 15 and see if it helps or not along with see if any OAs or hyponeas pop up with less max.

Are you on your back or on your side at the beginning of the night?

Any nasal congestion happening? Nasal congestion can be perceived by the machine as flow limitations and it responds as such but more pressure won't fix nasal congestion. Instead you have to fix the nasal congestion by normal methods...meds, sprays, rinses, etc.

Approx how long does it take you to fall asleep?

The pressure increase is due to the amount of flow limitation you experience during that part of the night. Two experiments you could try -- but only one at a time, so you know what changes in outcomes are due to what changes in your settings. I'd suggest trying the first experiment first.

* Increase your EPR to 3. This can help to decrease flow limitations. Try it a couple of nights and see what happens to your AHI and your pressures. Also take a careful note of how you feel during the night and the next day.

* Set your maximum at, say, 14. Closely monitor what happens to your AHI. Again, take careful note of how you feel.

I'll be interested to know the outcomes if you try one or both of these experiments.

Pugsy wrote: ↑

Fri Sep 04, 2020 10:15 am

Are you on your back or on your side at the beginning of the night?

Always start on my back.

Any nasal congestion happening? Nasal congestion can be perceived by the machine as flow limitations and it responds as such but more pressure won't fix nasal congestion. Instead you have to fix the nasal congestion by normal methods...meds, sprays, rinses, etc.

Some. But I'm always doing something to mitigate as I can't fall asleep unless I can breathe thru my nose comfortably.

Approx how long does it take you to fall asleep?

Once I'm ready, I fall asleep fairly quickly. Within 5 minutes most cases.

The reason you have such a significant and abrupt pressure increase is because you have significant Flow Limitations. They are huge during the first session.

We need to figure out why you have so much FL, when you start your therapy.

Are your nasal passages clogging up? Is your initial head placement on your pillow creating a limitation on the airway? Is your sleep position different? Are you taking any kind of medication or sleep-aid?

Some things to try:

• Different sleep position
• Cervical collar
• Turn on Ramp to get you through that period
• Limit you Max Pressure to something you can tolerate

A little caution regarding changing Ramp and Max Pressure. The machine *is* increasing its pressure to address the Flow Limitations. It's going where it needs to go. Preventing that *might* contribute to the Flow Limitations becoming full fledged Apneas.

Miss Emerita wrote: ↑

Fri Sep 04, 2020 10:15 am

The pressure increase is due to the amount of flow limitation you experience during that part of the night. Two experiments you could try -- but only one at a time, so you know what changes in outcomes are due to what changes in your settings. I'd suggest trying the first experiment first.

* Increase your EPR to 3. This can help to decrease flow limitations. Try it a couple of nights and see what happens to your AHI and your pressures. Also take a careful note of how you feel during the night and the next day.

* Set your maximum at, say, 14. Closely monitor what happens to your AHI. Again, take careful note of how you feel.

I'll be interested to know the outcomes if you try one or both of these experiments.

Since both you and pugsy recommended trying lowering max maybe I'll try that. Note: this is the first time the machine blasted the mask off my face basically. Oscar tells me that the machine does in fact ramp up quickly to 20 every night.

Thanks much for the suggestions!

I am the same way with my nose...if I can't breathe through my nose I can't fall asleep.

You can try limiting the max to say 15 and watch for an increase in OAs or hyponeas. Just because the machine thinks it needs to go to 20 doesn't mean we should just let it go there if the going there creates more problems than the FLs it is trying to kill creates a problem.

You are new to therapy. Maybe revisit allowing the machine to go higher (when it wants to) at a later date when the going higher might not disturb you so much.

On your back...worse position in the world for making OSA worse but sometimes we can't sleep in any other position.
Do you ever wake up on your side? That might explain the difference in pressure needs and respiration pattern.
If you can comfortably sleep on your side...try starting the night out on your side and see what happens. I am betting the FLs will reduce a bit and your pressure needs will also reduce.

The other alternative ....wearing one of those soft cervical collar to help keep the chin up and the airway open a little better.
Lots of people do it....some people (like me) simply wouldn't find that option attractive but it is an option.

But your machine wants to give you more pressure because of the flow limitations. It's just doing its job. You can limit it though if you wish.

Dog Slobber wrote: ↑

Fri Sep 04, 2020 10:28 am

We need to figure out why you have so much FL, when you start your therapy.

Agreed! But how?

Are your nasal passages clogging up? Is your initial head placement on your pillow creating a limitation on the airway? Is your sleep position different? Are you taking any kind of medication or sleep-aid?

Nasals are clear enough for me to breathe thru my nose when I fall asleep. Might they be clogging as soon as I fall asleep? Dunno. Not taking any kind of sleep aids. Do take DHEA right before bedtime.

Limit you Max Pressure to something you can tolerate

I've been tolerating max pressure fine this whole time until last night where the mask was blasting off my face which woke me up. Oscar tells me after this massive ramp-up (consistently) I'm fine the rest of the night.

A little caution regarding changing Ramp and Max Pressure. The machine *is* increasing its pressure to address the Flow Limitations. It's going where it needs to go. Preventing that *might* contribute to the Flow Limitations becoming full fledged Apneas.

I hear ya. So..... monkey with the Ramp? Or EPR? Or....?

Pugsy wrote: ↑

Fri Sep 04, 2020 10:35 am

On your back...worse position in the world for making OSA worse but sometimes we can't sleep in any other position.
Do you ever wake up on your side? That might explain the difference in pressure needs and respiration pattern.
If you can comfortably sleep on your side...try starting the night out on your side and see what happens. I am betting the FLs will reduce a bit and your pressure needs will also reduce.

Don't think I could fall asleep apart from starting on my back. For whatever reason, as I acclimate to the mask and it "disappears", then I can roll onto my side and sleep that way - and frequently do.

grounded wrote: ↑

Fri Sep 04, 2020 10:36 am

A little caution regarding changing Ramp and Max Pressure. The machine *is* increasing its pressure to address the Flow Limitations. It's going where it needs to go. Preventing that *might* contribute to the Flow Limitations becoming full fledged Apneas.

I hear ya. So..... monkey with the Ramp? Or EPR? Or....?

I don't like changing too many things at once.

I like the limiting the Max Pressure option the best because you still get all the telemetry from the machine. Playing with Ramp, you will lose that.

After a bit consider EPR, but I don't really agree with Miss E, about increasing EPR reducing FLs. Often people increase pressure, and compensate by increasing EPR to have a similar experience. It's the increased pressure that reduces the FLs.

Increasing EPR doesn't always reduce FLs in all people. You don't have much room to increase it anyway. You are at 2 now and 3 is the most you can get.

If it were me...I would limit the max to 15 and see how I did with it and watch for a potential increase in OAs or hyponeas and not worry about the FLs as long as I was sleeping good and feeling good.
If OAs and hyponeas stayed low and I was sleeping good and the pressure changes no longer caused wake ups...I wouldn't worry about the FLs. Sometimes killing them causes more problems than they cause.

grounded wrote: ↑

Fri Sep 04, 2020 10:27 am

Pugsy wrote: ↑

Fri Sep 04, 2020 10:15 am

Are you on your back or on your side at the beginning of the night?

Always start on my back.

Start on your side, see if that makes a difference.

palerider wrote: ↑

Fri Sep 04, 2020 11:11 am

Start on your side, see if that makes a difference.

Wish I could. Don't know why I struggle so much to do that, but alas I do...

Pugsy wrote: ↑

Fri Sep 04, 2020 10:57 am

I wouldn't worry about the FLs. Sometimes killing them causes more problems than they cause.

Where can I read more about flow limits? Is that where the airway is getting restricted due to the relaxing tongue & throat, but short of a full closure?

There's a pretty good introduction here:

http://www.apneaboard.com/wiki/index.ph ... limitation

For some people, FLs are inconsequential. For others, they can make a big difference. If you have to exert extra effort, breath after breath, to complete your inhalations, that is tiring in itself. And this effort can also disrupt sleep architecture.

EPR or pressure support can be very helpful in reducing flow limitations -- not always, but pretty often. I'm attaching a couple of FL graphs showing EPR of 3 (Airsense 10 Autoset) compared to pressure support of 4.8 (VAuto Aircurve). (EPR counts down from the inhalation pressure; pressure support counts up from the exhalation pressure. But it's the same idea: higher pressure when inhaling; lower pressure when exhaling.) For me, reducing FLs really improved how rested I feel. That might not be true for you, of course; we're all different.

Your charts are interesting because you have the very heavy FLs at the beginning of the night, which does suggest something like a postural problem, as other people have pointed out. Then again, your FL graph is fairly busy for the rest of the night too.

You are getting an abundance of excellent ways to follow up. You are not going to hurt yourself trying any of these experiments (higher minimum pressure, higher EPR, change in sleep posture, etc.) Unless one of them is a disaster, I'd suggest that you give the things you try a few nights before you evaluate them.