Hello everyone.
I am new to this forum so I will introduce myself. :-)
WHO I AM
My real name is Daniel and I tell everyone to call me Dan. I am a 71 year old retired engineer bilingual French-English. I live in Canada, province of Quebec, city Shawinigan. Unfortunately, I am a smoker.
MY SLEEP STUDY
I was diagnosed with apnea and part of the results of my sleep study were:
Central apneas : 1.3
Obstructive apneas : 23.3
Mixed apneas : 1.7
Hypopnea : 7.7
Apneas + Hypopnea : 33
RERAs : 2.3
That study was done in February 2021.
MY CPAP
I got Philips machine first but problems with the sleep clinic (not the Philips recall) forced me to change the machine. I then got à Resmed Airsense 11 and started using it December 22, 2021.
MY THERAPY
Untill June 2022:
I struggle to get my numbers down. I got different advice for the pressure settings and played with those with no real improvement. The final pressure settings are now 10/20 which is the maximum for the high pressure. It was also suggested I wear a cervical collar because of probable "positional apnea". I tried two collars with the second one showing some improvement. I call it a semi-rigid collar. My results were still up and down and not really good.
After June 6, 2022:
As I was searching internet for information about apnea and treatments, I stumble on an article about a MAD (mandibular advancement device) that would be a help for some people. So I got one device from Amazon to try. It is not something I should keep wearing for long because it can have a bad impact on the mouth and teeth (so says my dentist). From the first night I tried the MAD, I saw my numbers drastically improve as shown in the table below.
If those results stay as good as they are now, I will get a MAD made by a professional.
MY QUESTIONS
My big question is when you look at my numbers (images below), is it possible to improve on that or should I be happy with what they are?
I started yesterday to stop drinking coffee with the hope I will cut down the fragmented sleep which is my usual night. For now I do not seem to experience caffeine withdrawal problems.
Finally, can you think of anything else I could do for improvements?
I have more information available should you want it. Thank you for any comment you would submit.
Your post was probably delayed due to the graphics. I just saw it today.
On your sleep test are those numbers events per hour? If so an AHI of 33 is moderate apnea and should be treated. I am a bit surprised that the pressure you are using is as high as it is (95% at about 18 cm). My AHI at diagnosis was 37 and I use 11 cm of pressure.
I find your results from the MAD device very interesting and are worth exploring. They are expensive but it would be worthwhile getting one made by a dentist.
You are using EPR at 3 cm and full time. People respond differently to EPR. I went a long time with EPR at 3 cm but on ramp only. When I switched to full time at 2 cm my hypopnea events went down significantly and my AHI improved from about 2 to less than 1. It is hard to predict the value of EPR and the best way is to try with it on and without it to see what works best for you. For some having EPR off can reduce the frequency of obstructive events and as a result reduce required pressure. Trial and error seems to be the only way to figure out what works best for each individual.
I have had issues with central apnea which you do not seem to have. The other big improvement I got and especially with respect to CA events was to switch from auto mode to fixed pressure CPAP. In auto it seems that the machine can sometimes start to chase its tail and raise pressure too much. I also think it can raise pressure too much based on hypopnea events which may be central (open airway flow reduction) in nature rather than obstructive. The machine is smart enough to not raise pressure in response to central events, but it seems to not be able to distinguish between central hypopnea and obstructive hypopnea. In any case I was running pressures in auto up to 15 cm, and now I am using a fixed 11 cm of pressure with full time EPR at 2 cm. It may be worth a try to see if it works for you. It is a trial and error process and based on your one night you may want to try 15 cm to start. And at least in the beginning make 1 cm changes in each direction to zero in on the optimum fixed pressure for you. Once you get close then you can fine tune with smaller steps. See my history below to get some idea how I did. Not very scientific, just patient trial and error!
On coffee I drink lots of it, but never after 12:00 noon, or any other caffeinated drinks in the PM or evening. There is some good sleep info at this link. It was set up by a professor of pharmacy in Nova Scotia I believe. His objective was to try and get seniors off sleeping pills.
Thank you Sierra, your comments are greatly appreciated :-)
On your sleep test are those numbers events per hour?
Yes, they are.
the pressure you are using is as high as it is (95% at about 18 cm)
At the beginning the pressure settings were Min. 6.0 Max 16.0 (cmH2O). The results were not very satisfactory so I tested different settings. I got the best results at the settings Min. 10.0 Max. 20.0 (cmH2O). One thing I just realized is that all the tests I made was before I started using the MAD. I will retest with different pressures and see if there are positive effects.
You are using EPR at 3 cm and full time.
I do not have a clear understanding of what the EPR is or do. Based on your results, I will try different settings and check for improvements. I think I should do those tests after the ones with the pressure.
I read somewhere that the caffeine effects could last for 1 to 2 weeks. Since I have no problem cutting it, I am waiting for a couple of weeks before concluding on its effect on me. I used to drink coffee throughout the day and even at night when I woke up.
What is hard for me is getting the patience required. I am not naturally very patient.
P.S. Is there a place instructing how to post. I got this one by chance I think.
I started my tests with pressure. After one night with 4 sessions, the results are not conclusive. I will continue those tests for a few more nights.
I read somewhere that the 95% Flow Limitation should ideally be below 0.1. My average for the last 3 months is more 0.3. Is it something I should try to bring down and if so, how can I do that? Is this a case that would benefit from a BiPAP?
Did you export the data to produce that graph?
I export the data to CSV files and then use them with Excel to get different graphs.
The other possibility is a switch to the For Her mode. I believe the A11 machine includes that as an option.
I don't see that option on my A11.
BiPAP I believe they can go up to about 10 cm
The AirCurve Vauto specifications say 25 [cm H2O (hPa)]
I think the first thing I would try on your machine is tightening up the pressure range by increasing the minimum pressure. I would suggest 14 cm as a minimum
My test last night was with pressure settings at 15 cm and 20 cm for the first 45 minutes and then I reset the pressure to 12-20 cm because there were leaks at the mask when I exhaled. I will give it a shot at 14 cm.
a trial at a fixed pressure (CPAP) may be worth a try
I will have to check on my A11 to see how to set such fixed pressure. As for the ramp, I don't really need it. I fall to sleep very rapidly, within a few minutes. I was thinking to check if I could just eliminate the ramp and see what it would do.
Since there are many things to set to finally have a clear picture if that is possible, I am going step by step with those tests. A few more nights to try and finalise the pressure settings.
Does someone has ever seen something like my last night sleep?
That is for the same night. No change in anything. I got up and went back to bed into the same sleeping position. For both sessions I woke up in the same position.
Why is my second session different? Could there be clues in some other OSCAR graphics?
Just for example you may get away with a maximum pressure of 15 cm, but with a 10 cm pressure support. Then the machine pressure will alternate between 15 cm on inhale and 5 cm on exhale. This could be much more effective and more comfortable than what you are getting now, which is 20 cm on inhale and 17 cm on exhale.
I am confused. I can set my machine (AirSense 11) with a range of 4 to 20 cm. So I could set it to 5 - 15 cm. Is that what your saying? I had it set to 6 - 15 which is close.
Keep in mind that I am not a medical professional. Like you I am a retired engineer with sleep apnea that is now pushing 73! Your summary is basically correct. My theory is that you need breathing assistance more than just higher pressure. Breathing assistance is gained with more pressure differential between IPAP and EPAP. My hope would be that with more differential, your IPAP would not need to be so high. The reason is that you don't seem to be having a high obstructive apnea frequency, and it is flow limitation that is causing your CPAP to raise pressure, when what you really need is more differential.
Engineers like graphs. This section of the VAuto Clinical Manual may help in understanding how they work.
Here I am once more with questions about flow limitation.
From advice on the subject, my case seemed to require a change of my AirSense 11 for a BiPAP (Resmed AirCurve vAuto).
I found that it is almost impossible to get such machine without a prescription which means I have to convince my lung doctor to change her initial prescription. So far I have not been successful.
I am thus trying to find more arguments to convince my doctor.
So, I took a different look at my results. Almost all graphs out there are time based. Showing different events per hour. I wanted to see if there is a relation between my AHI, my pressure and my flow limitation. Like you said, engineers like graphs :-)
The graph I produced confirmed pretty much one information I got that flow limitation under 0.1 is a good objective. You can see on the graph that below the 0.1 value for flow limitation, I have no events occurring. That is a clear indication for me.
Also shown on the graph is that higher the flow limitation is, higher the AHI also is.
From WiKi: .... Flow limitation may be inspiratory (during inhale) or expiratory (during exhale). It refers to any condition which impairs the flow rate of air through the respiratory tract.... Flow limitations can result from anatomical narrowing of the airway, airway obstruction, and positional obstruction where the airway is restricted due to an individual's sleep position resulting in occlusion of the airway (I am wearing a cervical collar). EFL may also result from intolerance to CPAP pressure during exhale. Both IFL and EFL seem to respond well to bilevel therapy where the exhale positive air pressure (EPAP) is a lower pressure than the inhale positive air pressure (IPAP).
So I do need to fight flow limitation which in my case sometimes goes up to 0.8.
I am thinking of presenting this argument to my lung doctor.
If you can improve/correct the above, please do so.
Thank you.
Yes, flow limitation and obstructive events are related. Flow limitation often precedes an obstructive event. I think your basic problem in getting a prescription for a BiLevel machine is that your current machine is getting your AHI below the standard 5 level which is considered acceptable treatment. It is struggling a lot to do it, and frequently is hitting the 20 cm limit of the APAP, but the average AHI is still reasonable from a medical treatment perspective. So, the AHI is the weak point of your argument for a BiLevel machine. Your strong points is the duration of time that the machine is at 20 cm of pressure. I would expect that is not all that comfortable and may impact your sleep, and she should be told that (if it is true). The big advantage of the BiLevel for you is not the maximum pressure increase, it is the Pressure Support of up to 10 cm that would be of value to you. She should know that Pressure Support is what is needed in the case of flow limitation issue. Again you would need to convince her that flow limitations are a problem affecting your sleep, and need to be reduced independently from reducing the frequency of obstructive events. It is a bit of speculation on my part, but I would expect your overall pressures would go down if you had more than 3 cm of pressure support. What you really need is breathing support from a bigger differential between IPAP and EPAP. This addresses flow limitation on both inhale and exhale.
The other evidence you could give here is a zoomed in shot of your flow rate during these times of flow limitation. Not sure what yours looks like, but my wife has higher flow limitation than I do, and here is an example when FL gets up to 0.5 or so. You can see that the tops (peak inhale flow) of the breaths are flat topped and irregular. If yours are similar, that would be something you could take an image of an show her.
From the look of the flow chart it would appear my wife suffers more from flow limitation on inhale (up direction) compared to exhale.
Maybe it is because it is late and I can't get my fingers to hit the right keys, but this is my third attempt with this message.
To prepare my arguments for my doctor, I took a different look at the presentation of the data. Almost all graphs I have seen are time based and I thought of producing some based on the Flow Limitation.
The 2 first ones demonstrate that if I can get my Flow Limitation down to 0.1 as I was advised, I should get much better results.
The 2 last ones show that the pressure is maxed out above 0.1 for Flow Limitation. Since it seems only a BiPAP (I think) can lower Flow Limitation, there is my argument.
I would again greatly appreciate any comments you would submit.
BTW, should you like to have similar graphs, I can make them for you if you are not too familiar with Excel. I would only need your CSV files for the period you would like covered. To keep private, you can send anything to my email address:
I hope this is also useful for you and many thanks again for you superd support :-)
I am not sure if you have any time where EPR was set at 0 cm or off? The EPR was off for 1.12% of the total time of treatment and is was set to Ramp Only for 7.49%. I don't think it is significative to see a difference since my stuff goes up and down all the time.
I have a private insurance that covers CPAP but they have a time period of 5 years wait before you can submit a new reclamation.
One last thought is that if you are prepared to pay for a machine, there are no regulations that I am aware of preventing you from buying a used machine.
I did search for used machine and found only dealers that still require a prescription to buy one.
The only one I found without the requirement is shown on Facebook. I sent the guy 3 requests for him to contact me. He never answered.
I did a few graphs based on pressure but I don't think they are very useful.
So I will now request an interview with my lung doctor and do the best I can to convince her to write a new prescription.
