I need help with ASV settings please

[Asjb]

I'm into the 12th week of using ASV. Generally a great success, with no 'centrals' or 'obstructives' reported since I started and fatigue much improved. But I continue to have some noticeably less good nights - either the AHI increases (from, say, 0.2. to 2.0) and/or (often associated) a very poor nights sleep. This occurs 2-3 nights/week.

Over the three months my mean pressure has been 13-14; 90% pressure 15-17. Leaks are very well controlled more than 95% of nights - and the poor quality nights don't correlate with maximum (but OK, less than 20 and brief) leaks. I take all possible steps to sleep on my right-hand side and I think this has been pretty successful. (My diagnostic test showed position-dependent apnoeas on my back but also just as bad on my left side). I use an oximeter a couple of nights a week and mean pO2 is excellent at 96% and no significant desats - so I think the intermittent tiredness is not O2 related.

I have tried fixed EPAP min of 10 or 11; tried auto EPAP at 10-12. Pressure support of min 1, max 6, up to min 2 max 8.

For the last five nights (I haven't updated the Board control panel): auto EPAP 11-13, PS min 1, max 6. Woke unrefreshed and tired each morning. Last night's Sleepyhead pics are attached and are typical.

I don't have a sleep doctor any more and my technician is not really au fait with the Resmed ASV. I don't mind too much what the AHI number is (within reason…), I would just like more nights with refreshing sleep. After trying these assorted pressures I now haven't a clue what I am doing! and I would be grateful for advice on settings please. But given that, throughout these months, I have had poor quality sleep with an inspiratory pressure of 18 or more - I guess it must be micro-waking me repeatedly. So I need a trade-off perhaps? But if so, what?

Thank you if you can help.

http://imgur.com/a/LsC2K

PS how does one post thumbnails from Imgur.com? - their webpage doesn't seem to give that as a choice

[Sleeprider]

Your chart is pretty interesting for that period. It would helpif you would shrink the calendar by clicking that triangle next to the date, and maybe turning off the pie chart so the machine data and tidal volume data becomes visible. This tutorial describes how to organize the charts: http://www.apneaboard.com/wiki/index.php...ganization

The period you zoom into on the chart is a periodic breathing pattern with hypopnea terminating in recovery breathing with an interval of a minute to 1-1/2 minutes. We can see the machine attempt to correct the hypopnea by increasing pressure support during periods of suppressed breathing, but not a lot of response in your respiratory volume. The flow rate before and after the event appears to suggest a low tidal volume overall.

Just to review (please correct if I'm wrong) your using auto mode with EPAP min is 11.0, EPAP max 13, PS min 1 PS Max 6?

[Asjb]

Dear Sleeprider - thanks so much for taking an interest. You've been very helpful to me in the past too. I have officially <lost the plot> about my settings now!

I've uploaded five more images on:
http://imgur.com/a/5FQff

The first one is a better screenshot of last night, that I linked in my original post. Yes, you are correct, that was auto mode with EPAP min 11.0, EPAP max 13, PS min 1 PS Max 6.

Then a bad night's sleep, February 1st, with a very similar pattern to last night (two screenshots). Pressures that night were auto-EPAP 10-12 with PS min 1.4 & max 8.
And a PS I'm always bradycardic like this - damage to my sino-atrial node and on a beta blocker. Longstanding and nothing to worry about - I am fine and stable heart-wise and I don't have cardiac failure. The minimum pO2 of 84% registered in the data for that night I feel confident was an artefact - I've not been dipping below 89% (and that's been very rare) since I started with an ASV machine.

Then for comparison an excellent night's sleep, February 8th, & an AHI of 0.1 (two screenshots). That night the pressures were auto-EPAP 10-12 and PS min 2-7.

I appreciate it rather looks like I change my pressures every night, but I don't. I let things bed in for at least 5-6 nights before changing anything again.

I don't know if it's relevant but I've posted before that I have a genetic muscle disorder which gives me intermittent floppy paralysis (minutes to hours at a time) and I know that when it happens when I am awake that it affects my respiratory muscles too - noticeable hypoventilation and it probably collapses my upper airways a bit more too. But it's nothing catastrophic, I'm very used to it now after 50 years of it happening most weeks.

Thank you again - I very much value your expertise.

[Sleeprider]

That February 8 session you uploaded looks a lot better. It's nice to have the SpO2 data, although it would be more useful to see where the minimum occurs in relation to events. The average looks quite good. I originally though from the appearance of the first graph posted that routinely hypoventilate, but your average tidal volume and other data contradict that, and so that aspect of your sleep respiration looks great. So no need to increase minimum PS.

There is zero indication of obstructive issues with EPAP Min set to 10.0, so that is a safe baseline, and I don't see any reason to increase your EPAP. If anything, I think you can experiment with lower EPAP Min, and recommend you try slowly decreasing the EPAP down towards 8.0. This should provide good respiratory support to prevent obstructive and flow limitation events, and may let us work with more PS Max to deal with the hypopnea and periodic breathing events. If we see obstructive events pick up, then we'll know we lowered EPAP to the threshold or too far.

A PS Max of 8.0 worked fine, and the recent PS Max of 6.0 clearly was unable to resolve hypopnea and mixed events. The machine in auto mode should the pressure support needed to maintain respiratory volume as long as you have an open airway, so I think you need PS Max of 10 or more to overcome resistance apparent in the February 1 data. This should allow the machine to induce the volume into your breathing during those episodes. It may or may not use all of the support you allow, so let's see what happens. I have worked with people that allow more PS in some cases, but without chronic restrictive lung disease, this should get the job done.

Summary, EPAP min 8-9, PS min 1.0, PS max 10. The usual disclaimers apply. I have no expertise, and this is based on review of the available information and your description of where you're at in therapy. Good luck, and be sure to post back your ideas and results.

Tom

[Asjb]

I originally though from the appearance of the first graph posted that routinely hypoventilate, but your average tidal volume and other data contradict that, and so that aspect of your sleep respiration looks great. So no need to increase minimum PS......There is zero indication of obstructive issues with EPAP Min set to 10.0, so that is a safe baseline, and I don't see any reason to increase your EPAP. If anything, I think you can experiment with lower EPAP Min, and recommend you try slowly decreasing the EPAP down towards 8.0.......
Summary, EPAP min 8-9, PS min 1.0, PS max 10.
Tom

Hello again - thank you so much, extremely reassuring. May I just check - you recommend to take the min EPAP slowly down from, most recently, 11, towards 8 (as low as remains effective against obstructives). Shall I stay on *auto* EPAP, and if so, do you recommend to reduce the max EPAP by the same amount? e.g. move now to, say, min EPAP 10.4, max EPAP 12.4, or shall I keep the max EPAP as it has been over the last week i.e. at 13?

I'll also make the PS changes you recommend, from tonight.

Thank you again. Fingers crossed!

[vsheline]

Hi Asjb,

Those hypopneas and apneas in original post look clearly obstructive, so I suggest not lowering Min EPAP. The apneas are marked as of unknown type only because your machine never tries to detect central versus obstructive apneas. So apneas will always be scored UA.

Obstructive events have a triangular envelope, wherein the Flow restarts suddenly with deep recovery breaths, followed by the peak Flow per breath getting smaller and smaller until we are again in apnea or hypopnea.

On bilevel machines (like yours), usually the way to avoid obstructive events is to raise the Min EPAP.

Agree with suggestion to raise Max PS. Needs to be at least 8 or 10 to adequately "breathe for us" during central events.

Although Min PS of 1 may be doing okay for you, raising to 2 or higher would make it easier to breathe against high EPAP pressure which will sometimes be needed to avoid obstructive events. Also, I think it would provide more consistent PS and therefore would be easier to avoid leaks if Min PS is not way lower than Max PS. I suggest Min PS at least 2.

How have you been doing as far as air swallowing?

Take care,
--- Vaughn

I originally though from the appearance of the first graph posted that routinely hypoventilate, but your average tidal volume and other data contradict that, and so that aspect of your sleep respiration looks great. So no need to increase minimum PS......There is zero indication of obstructive issues with EPAP Min set to 10.0, so that is a safe baseline, and I don't see any reason to increase your EPAP. If anything, I think you can experiment with lower EPAP Min, and recommend you try slowly decreasing the EPAP down towards 8.0.......
Summary, EPAP min 8-9, PS min 1.0, PS max 10.
Tom

Hello again - thank you so much, extremely reassuring. May I just check - you recommend to take the min EPAP slowly down from, most recently, 11, towards 8 (as low as remains effective against obstructives). Shall I stay on *auto* EPAP, and if so, do you recommend to reduce the max EPAP by the same amount? e.g. move now to, say, min EPAP 10.4, max EPAP 12.4, or shall I keep the max EPAP as it has been over the last week i.e. at 13?

I'll also make the PS changes you recommend, from tonight.

Thank you again. Fingers crossed!

[Sleeprider]

I have no disagreement with the suggestion for PS min of 2.0. It is a far more conventional setting and should be more comfortable in general.

The thought on lowering EPAP min is to see if obstructive issues arise or not. There were charts with good results with EPAP min at 10, so I'll admit it's a guess on my part. Vsheline uses these machines on a daily basis, and I really respect his opinions.

Asjb, your ideas to move pressure slowly is a good idea, and as mentioned above the most important thing is increasing PS.

[Asjb]

Dear Sleeprider and Vsheline,

quote: The apneas are marked as of unknown type only because your machine never tries to detect central versus obstructive apneas. So apneas will always be scored UA......

Ah - thank you. I didn't know that. I have clearly been falsely reassured by Sleepyhead always telling me with this machine that I have zero obstructives and zero centrals. Thus - with the Aircurve ASV, Sleepyhead 'obstructives' and 'centrals' will always be zero because they are flagged only as 'unknown apnoea', and one can tell which only by looking at the wave form. Have I got that right?

quote: Although Min PS of 1 may be doing okay for you, raising to 2 or higher would make it easier to breathe against high EPAP pressure which will sometimes be needed to avoid obstructive events.....

Last night I changed the PS to min 3 and max 10 and lowered the auto-EPAP to a setting that had been very comfortable previously, auto 9.6 to 11.6. (I know in principle one shouldn't change so much all at the same time, but there was logic, and your advice and my experience, supporting these changes).

And I've just had a very good night's sleep, AHI 0.2, & waking full of the Joys of Life (despite it being grey and below zero here in La Belle France).

It wasn't a good night for leaks, which is rare for me, but I'll sort that out. I recently started using Remzzzs mask liners and have been so stunned by their price! that I think I am not changing them often enough - I even tried more extended use one time by washing a liner, but it was but a pale reminder of its former self afterwards. A new Remzzzs each night would cover the cost of a decent second-hand CPAP machine after a year... When I finish the pack of Remzzzs I shall try the home-made approach and cut up a tee shirt. I've found having a mask liner very successfully stops all those annoying times being woken by noisy 'mask burps'

quote: How have you been doing as far as air swallowing?

Well now. Never any abdominal pain, so the wind is basically not a problem. But occasionally a little delicate socially. And at home I can always blame the cat!

Thank you both again for your wise advice. Very much appreciated.

with my best wishes

[Sleeprider]

Well then! Yesterday was a good day. Keep at it and I bet this will all come together. With increased pressure support, you should not revisit some of those ugly looking apnea / hypopnea periods. Keep in touch on this this thread and hopefully things are getting closer to your needs now.

[vsheline]

Thus - with the Aircurve ASV, Sleepyhead 'obstructives' and 'centrals' will always be zero because they are flagged only as 'unknown apnoea', and one can tell which only by looking at the wave form. Have I got that right?

Right.

Higher Min PS is good for increasing our average SpO2 by increasing our average ventilation, but I would not expect the higher PS to keep obstructive events away.

Usually, to keep obstructive events away, avoiding bad sleep positions is the best approach, when feasible. I think the next best approach for lowering obstructive events is to raise EPAP.

It wasn't a good night for leaks, which is rare for me, but I'll sort that out. I recently started using Remzzzs mask liners and have been so stunned by their price! that I think I am not changing them often enough - I even tried more extended use one time by washing a liner, but it was but a pale reminder of its former self afterwards. A new Remzzzs each night would cover the cost of a decent second-hand CPAP machine after a year... When I finish the pack of Remzzzs I shall try the home-made approach and cut up a tee shirt. I've found having a mask liner very successfully stops all those annoying times being woken by noisy 'mask burps'

I am very careful to not follow manufacturer's directions to stretch the liner, but eventually (after a week or so) the liners stretch out too much to use.

I place them in a small mesh laundry bag for washing small items and wash them with my whites with just an ounce of bleach for the whole wash, and when still damp I press them.

quote: How have you been doing as far as air swallowing?

Well now. Never any abdominal pain...

Good.