I have had very little help from sleep doctor #1 (Nov, 2021 in-lab sleep study was useless) or CPAP Vendor. I am waiting for results from in-lab sleep study conducted Jan, 2022 ordered by sleep doctor #2, who seems to be very competent, but extremely hard to schedule time with. In the meanwhile I have been using a Resmed S9 with well-fitted Resmed AirFit N30i nasal mask, and reading all I can about CPAP treatment and how to 'dial in' the correct settings. I just received an Airsense 11, but suspect it may be defective (delivers fixed pressure when settings are on Auto, causing bad headaches when I wake up), so trying to find the best settings on S9 before I start dealing with the AirSense 11.
I would greatly appreciate some help. I was impressed with the way Sierra found personal ideal settings by following a protocol of: find lowest possible max pressure possible to achieve low AHI; narrow pressures; find a fixed pressure (if possible) with EPR on Ramp Only, lower max pressure to reduce central apneas, then turn EPR back on to Full Time Level 2. Can you help me follow the same protocol to find my ideal settings? I have 18 days of Oscar data, with last night's data posted below. Please let me know if my Oscar data is not in the proper format. I welcome your questions and your advice.
Thank you for your quick response, Sierra. I have made the chart changes you suggested. The charts are much more readable. I will look into a different pillow and cervical collar.
BACKGROUND
You are correct. Here are my current settings. Resmed S9 Mode: Auto Min Pressure: 6.0 Max Pressure: 9.6 Ramp: 30 min EPR: Level 3
Some additional information:
In this period of adjustment, I’m working out the ‘bugs’. In 27 days of using CPAP, I’ve experienced each of the following: a. I had an ill-fitting uncomfortable mask (9 days) with large mask leaks. Now have a proper fitting mask with no leaks. b. My mask came off while sleeping c. My machine suddenly quit and had to be reset d. I forgot to insert the SD card e. I forgot to fill the humidifier f. Therefore, I have ~13 nights’ data that I think are reliable
I believe the CPAP machine sometimes records apneas when I’m awake. When I know for sure the time intervals when I was awake (sometimes 1-2 hrs at a stretch), I manually filter these ‘awake apneas’ out. a. 13-night average, CPAP Recorded AHI: 7.87 b. 13-night average, Manual Filtered AHI: 4.46
SETTING THE CORRECT PRESSURE
TYPE OF APNEAS
I received my in-lab Sleep Study report yesterday. This study did not include titration with a CPAP machine. Total sleep time: 3 hr. AASM AHI: 79/hr Obstructive Apneas: 1/hr Central Apneas: 38/hr Hypopneas: 40/hr
OSCAR data from 13 nights’ at-home CPAP data (Manual Filtered) AHI: 4.46/hr Obstructive: 2.52/hr Central: 1.29/hr Hypopnea: 0.65/hr
Questions:
GENERAL QUESTION
Please feel free to ask for clarification or more information. I am so grateful for your help.
Good Morning Sierra! Thanks for checking in. I am so appreciative of your continuing to help me troubleshoot my CPAP therapy.
I’m still using the S9 to ‘dial in’ the correct min/max pressures. I haven’t wanted to complicate matters by using the Airsense 11. As soon as I feel the min/max pressure is close to optimal on the S9, I plan to switch over to the AS11. I may try the AS11 for a night or two in order to provide you with data to help troubleshoot the problem.
Thanks for offering your suggestion about why the AS11 may be at a fixed pressure. The problem is it stays at the MAX PRESSURE, not the START RAMP PRESSURE, despite the fact that I've set a min pressure (6.0) and a max pressure (9.4). (See OSCAR data for Feb 10 below.) I have spoken with both the vendor and with ResMed customer support about the fixed max pressure, but have gotten nowhere.
On Feb 11, I mistakenly set Mask = Pillows instead of Nasal (Air Fit N30i). Would this setting account for the large Flow Limit (typically my Flow Limit on the S9 is <.20)? What effect would the inaccurate "Pillow" setting have on pressure delivered? (See OSCAR data for Feb 11 below.)
In terms of my CPAP treatment, I’ve been doing well following your protocol. I have been increasing the max pressure by .2 cm every 2-3 nights. With these tiny increments, I am able to avoid morning headaches caused by too big a jump in pressure. As of Feb 20, I’m up to max pressure = 10.0 (see OSCAR data for Feb 20 below).
Results: I got 6.5 hr sleep (vs 3-4 hrs), woke up just once last night (vs 3-7x), but awoke and stayed awake from 1-2 AM (typical not to fall back to sleep quickly). I felt moderately refreshed this morning (vs feeling very tired upon waking).
It may sound obvious to you, but your advice to observe at what pressure apneas were occurring was a key to my understanding how to determine optimal pressures. I’m still experiencing most apneas (OA and CA) @ max pressure, so I will continue to slowly increase the max pressure. I’m watching central apneas closely to see if they increase.
Two questions: Once I establish a max pressure (let’s say, 10.5), why would increasing the min pressure reduce apneas? What is a typical pressure range – 2 or 3 cm (ex: min=7.0, max=10.5)?
This forum is providing me with support and useful information to achieve effective CPAP therapy, which I’m not finding anywhere else. It would be much more frustrating and lonely without myapnea.org. I am grateful.
Your more recent Daily graphs are showing a much higher incidence of CA or central apnea events. Sometimes these events occur when CPAP treatment has been started, and are primarily due to the increased pressure of the CPAP upsetting the breathing control system. In these cases the CSA is called treatment emergent central apnea. In most cases this effect goes away in 6-8 weeks after treatment is started.
In an earlier post you said that your sleep study indicated a very high proportion of CSA events. That is a bit unusual in that no pressure is used during the sleep study test. And the first OSCAR report you posted showed very little CSA which was unusual considering the sleep study outcome. However now you are showing more CSA. This makes me a little less optimistic that minimizing pressure for your treatment may bring your AHI down, or at least the central part of it. You should have a look at the article at the link below to see if any of the causes of central apnea may apply to you. I have seen outcomes from people that live at high altitudes have issues with central apnea for example. There are heart conditions that may lead to central apnea. And there are medications which can cause it as well. The main ones are opiates. I have never taken them, but I do take a beta blocker (bisoprolol) for my blood pressure. It slows the heart rate and at least in my opinion must reduce blood flow rate. Reduced blood flow from heart conditions can cause central apnea. I discussed it with my doctor and convinced him to cut the amount of bisoprolol in half. I think he was skeptical but it did seem to help me. In any case have a read of the article to see if any of the causes may apply.
Central Sleep Apnea and Obstructive Sleep Apnea
The combination of obstructive and central sleep apnea is sometimes called complex apnea. The combination can be tough to deal with. More pressure can reduce the OA events, but cause more CA events. Some sleep clinics push people to move to a BiPAP machine if an APAP (like your S9 or A11) does not work. A BiPAP provides more pressure and more of a differential between inhale and exhale. Neither is really helpful for dealing with central apnea. If you do end up with persistent central apnea that cannot be treated with fine tuning your APAP, you may need to investigate an ASV (Adaptive Servo-Ventilator) with your sleep clinic. I recall you have an upcoming appointment, and that would be a good time to discuss. That said I still hope that there may be opportunity to further reduce your apnea without resorting to that option.
One of the patterns that I see very occasionally (once every month or two) is CSR ( Cheyne-Stokes Respiration). I believe that is associated with poorer blood circulation or perhaps other cardio issues. Here is what it looks like.
If you left click on your graphs repeatedly (or use the arrow keys) you can zoom in on the flow chart to see this level of detail. This may give you some help as to the nature of your central apnea. I click on the left end of the Minute Ventilation chart and move it up near the flow chart to see the relationship. When you see the Minute Ventilation cycling up and down that indicated unstable breathing control.
I hope that helps some. But, I have not given up on you being able to improve things with the machine you have now. The AirSense 11 is not really that much better than the S9 but you could give it a try in standard Auto mode. The biggest advantage of the A10 and A11 is that they have an AutoRamp feature. I see from your OSCAR chart that you must have that turned on. I like it.
You are obviously taking this very seriously and tracking your results. It reminds me of my early days trying to sort out my issues where I was also using a spreadsheet to track things. If you think things are getting better with respect to central apneas then that is a good sign. They may be treatment induced and are going away. Lets hope! One of the things I have found with my apnea which is about 2/3rds central on most nights, is how erratic it is. In the space of a week I can have a night over 2.0 AHI and another night at 0 AHI. I just take comfort that I am now averaging less than 1.0 for AHI.
I have never tried to correct my AHI for apnea when I am awake instead of sleeping. I think it does happen. Some call it "sleep wake junk". Fortunately I sleep well enough that I have never thought it was significant for me.
On the Cheyne Stokes Respiration I did some checking. It is reported and highlighted in green on the A10 machine and I assume the A11. It appears that feature was not in the S9. However it is easy to recognize by just looking at the flow chart zoomed in right before central events occur. It also helps to put the Minute Ventilation beside the Flow graph. Here is an example of what it looks like. Towards the left there are two events which did not last long enough to be flagged. I suspect they were obstructive events. This disturbs the breathing and you can see the Minute Ventilation gets upset. It settles out and then gets disturbed again. This results in three CA events in a row. When you see that wave in the breathing I am breathing deeper and deeper and then more and more shallow. It can start another cycle or cause a central. In any case that to me is what happens when the breathing control system is unstable. If it repeats enough times it gets flagged as CSR. When the breathing goes in regular cycles like this I believe I am asleep. My thoughts would be to look for times when you are seeing a number of CA events to see if there is any pattern like this. Or, look at the time after an obstructive event to see if breathing starts to cycle.
The AutoRamp on the A10 and A11 is really a hold, rather than a ramp. You select a ramp start pressure and the AutoRamp holds the pressure at that level until you fall asleep, then it ramps up to the minimum pressure. If you don't fall asleep in 30 minutes it ramps the pressure up anyway. I find it a comfortable way to go to sleep as I can set the pressure at what I find comfortable. and not have the pressure ramping while I am still awake.
@Sierra, I received all your messages last night. If it wasn’t for your encouragement, I would not have tried using the AS11. But I did use it, and it went well. Barring any unforeseen occurrence, I will be using it from now on. S9 is still available as my backup.
SETTINGS CHANGES
I tried changing from EPR Full Level 3 to EPR Ramp Only, and lowered the max to 9.0 from 10.0 (min/max 6.0-9.0). The result of the EPR change when I was trying to fall asleep I couldn’t catch my breath, it was hard to exhale and I was starting to get a headache. So I re-engaged the EPR to Full Time Level 2 (had been Level 3), and increased the min/max back to 6.0-10.0. Then I was able to fall asleep.
I realize the goal is to set EPR to Ramp Only in order to lower the max (where apneas are occurring), but wondering how to do that without the discomfort, and without losing sleep at the beginning of the night. Is the min of 6.0 too low?
AWAKENINGS
I woke up briefly 3 times @ 1.40, 2.50 and ~4 AM (my usual is 2-7x), but was able to go back to sleep quickly. The peak of the night for apneas was 2.40 AM. Is that what woke me at 2.50? After 5.5 hrs of sleep (avg: 6.5 hr), I woke up a bit tired. Hopefully I’ll wake up refreshed one morning.
CPAP STATS
Last night’s stats show OAs are down, CAs are up: (12-day avg in parentheses): OA=1.04 (2.78), CA=2.22 (1.43), H=0.44 (0.70), RERA=0.59 (no avg available).
AHI = 4.0 (avg=4.14 when awake apneas removed); machine-reported avg: 7.90. I’m not yet concluding that AS11 can tell the difference between asleep/awake, since I didn’t have long stretches of being awake last night. But it would be nice if AS11 could do that.
I know most people don’t look at the ‘Time at Pressure’ chart, but I’ve found it useful. I spent 79 minutes at max pressure 10.0. Events occurred at these max pressures:
Max 9.0 OA: 1, CA: 0
Max 9.2 OA: 0, CA: 3
Max 9.4 OA: 0, CA: 1
Max 9.6 OA: 4, CA: 4
Max 9.8 OA: 1, CA: 0
Max 10.0 OA: 1, CA: 5
As you’ve mentioned, the trick is to strike a balance when raising max pressure between reducing OAs and increasing CAs. Would you suggest continuing to slowly increase the max in order to reduce OAs at the cost of increasing CAs? Would that pattern make the case for getting an ASV rather than an APAP?
What settings would you suggest going forward?
THANK YOU!!
@Sierra, As you suggested, I increased AutoSet Min Pressure to 7.0, and EPR=Ramp Only. It was quite comfortable while falling asleep. See results below.
Unfortunately, my cat made a clatter in the closet at around 2.30 AM which woke me. My nose had gotten stuffed up, so I couldn’t breathe through the mask. I discontinued CPAP at that point. Yet another ‘this never happened before’ event: stuffed up nose. As each ‘never happened before’ event occurs, I check it off my list and feel thankful that I’m one step closer to finding the right CPAP settings for me.
Results: AHI was 6.51. An AHI comprised of CA = 2.17 and OA = .99 would be a very good night for me. However, the AHI of 6.51 also contains H=3.16 + RERA=1.18. Is there a way to tell if the Hs and Rs are due to obstructive or central apnea? I see some Hs on the inhale, some on the exhale. Or are Hs and RERAs not very important?
After ramping up, pressure went to the max, 10.0, and stayed there.
Based on 22 nights, Oscar data show at max<10.0, CAs averaged 1.5. When max>10, the CA average doubled to 3.0. Conversely, at max<10.0, OAs averaged 4.0. When max>10, the OA average dropped in half to 2.2. There are only 3 days’ data at max=10.0, not enough to draw a conclusion at this point, just to suggest a possible trend. Will keep watching.
What settings do you suggest over the coming nights to continue to home in on the lowest possible CAs and OAs? Do you suggest maintaining the same settings for a few nights before making a change?
I’m encouraged by the progress we are making. I’m feeling a little better rested today than usual.
@Sierra, I took your suggestions about chart layout. Happy to make more changes if it makes interpretation easier.
PRESSURE SETTINGS
I’m still experimenting with increasing max very slowly until there are no apneas @max pressure. I’d also like to increase min pressure to create the minimum range before I go to a fixed pressure (9.0, as you suggest) so I can compare fixed 9.0 to an optimal tight min/max range.
LIFE WITH AIRSENSE 11
I’m experiencing no discomfort from CPAP with the AS11 and even slept for 5.5 hrs without interruption last night until 3.30 AM, then couldn’t get back to sleep as usual. That’s a record for me. I’m feeling less tired during the day as a result.
With AS11, ‘Minutes in Apnea’ has decreased from 10 to 5 min, but Large Leaks has gone up from ~1.5% to ~ 2.5%, with 2 nights as high as 10%. I’m using the same mask – Resmed Airfit N30i, which is very comfortable, and I don’t feel any leaks while awake. Is 2.5% significant? Not sure how to fix the problem.
OSCAR CHART QUESTIONS
What is the relationship among Flow Limit, Minute Vent, Flow Rate and apneas? I’m trying to observe which occurs in what order. How do these metrics explain what is happening when CA and H events occur? Do you see any patterns of when OAs, CAs and H’s are occurring and how to reduce them? Or do we need more data?
Is there a way to remove sleep/wake junk (SWJ) data from Oscar charts at times you know you were awake? If I can’t remove the SWJ data, is there some way to denote on the charts the times I am awake?
A new day is dawning when I feel like a human again. Thank you so much!
Here’s an update…
I have officially used my Resmed Airsense 11 for 21 consecutive nights for >4 hrs and have a doctor’s appointment next week to confirm my compliance, so my insurance company will pay for the AS11 and consumables.
I have gradually increased min and max pressures over 3 weeks (see spreadsheet). The results (7-day averages):
AHI 4.40
Obstructive .94
Central 1.43
Hypopnea 1.87
My sleep dr seemed amazed that I achieved this AHI, given my January 2022 sleep study AHI of 79. He was surprised the CAs were low, given almost 100% of my sleep study apneas were CAs.
When I increased the max pressure from 10.4 to 10.6, OA, CA and H all decreased. I’m probably close to that tradeoff point you mentioned Sierra. If I increase max pressure, OA may go down and CA and H may go up. Will continue to make small pressure changes and hold them for awhile before making additional changes.
The AHI numbers may be moving in the right direction, but I still wake up 2-5x/night, with the longest stretch lasting only 2-3 hrs. I never feel completely rested, but am feeling a bit better than I did a month ago.
It’s taking a lot of patience to change only 1 variable at a time and giving it sufficient time to work. I will continue dialing in max pressure and other settings for CPAP, and will be trying a few more things to improve sleep quality. I tried melatonin, but it didn’t work for me.
Does my experience match MyApnea members’ experiences? How long did you use CPAP before you started feeling well rested? I realize everyone is unique, but it helps to have a realistic expectation.
First, I have to say you are doing an amazing job in tracking your progress and keeping the detailed spreadsheets. In looking at the spreadsheets a couple of things jump out to me. First since Feb 28 when you increased maximum pressure to 10.4 cm the OA frequency with the exception of one night has been really good. The average is under 1.0. This suggests to me that 10.4 cm is probably enough to control most of the OA events. The second thing that jumps out is that when you were using the S9 machine with EPR at 3 cm full time your Hypopnea was much lower and looks like it is well under 1.0 compared to nearly 2 now with EPR on ramp only.
Putting this together this is what I would do. First switch the machine to fixed pressure CPAP mode. You are spending very little time at less than the maximum pressure, and gaining very little with increasing minimum pressure. You may as well go to one fixed pressure that you can control. My suggestion based on your spreadsheet data would be to try 10.4 cm for the single fixed pressure. I would try that for a couple of nights just to confirm what it does. And next I would switch the EPR to Full Time with it set at 1.0 cm. Then if everything looks OK, increase the EPR to 2 cm and then 3 cm to find out if that will reduce the Hypopnea. The objective would be to only use enough EPR to reduce the Hypopnea but not increase the OA frequency.
And then after you determine the optimum EPR (the minimum you can get away with), then you could try lower fixed pressures to see what pressure you can get away with, without OA events going up. You may be able to get away with less than 10.4 and less might reduce the CA frequency.
You asked about sleep quality and I am a poor one to ask. I was diagnosed with an AHI of 37 or so, and next to zero CA events. But with treatment the CA problem emerged. And before diagnosis I was sleeping well (but snoring!). So, I did not see a big improvement in sleep quality, but I'm sure my wife appreciates the reduction in snoring. On the other hand, my wife was diagnosed at an AHI of 73 or so. Her treatment has brought her AHI down to 0.6 and she says she has an amazing improvement in sleep quality. But, I think my sleep quality is better than hers. She insists on having daily naps while I do my best to avoid naps during the day and try to sleep between 7 and 8 hours each night.
To give you some idea what it takes to get the machine optimized here is a screenshot of my statistics since day 1 with my A10 machine back in 2018. I kind of went through phases where I reduced the gap between min and max pressures. and then switched to a fixed pressure with many attempts to determine the best tradeoff pressure, and then finally to try EPR at 2 cm. I should probably try EPR at 1 cm but have not done that yet. As you can see, it is a long and winding road to get to some kind of optimum setting.
