position and respirator

[rada]

I am interested in the relationship between sleep position and SpO2. My doctor's advice had led me to believe that sleeping on my side was a way for me to address my OSA and so whether sleeping with a respirator or not I had been trying to sleep on my side. What I have found is that with respirator, I can get good SpO2 on my back (probably better than on my side), and I feel better skeletally, muscularly, and neurologically after a night on my back than a night on my side. Without a respirator, sleeping on my back is terrible for SpO2. For instance, two nights ago, I took off my mask in the middle of the night and slept without it on my back for several hours. My SpO2 suffered (several times below 87%). This night, I slept with my mask for 6 hours and another two hours without respirator on my side, and SpO2 stayed good while I was on my side. My tentative conclusion is that sleeping on my side helps SpO2 when I am without respirator, but that with respirator SpO2 on my back is better. I might speculate about some pathophysiology for this as follows: the respirator keeps the throat open and being on my back puts less pressure on my lungs; however, without the respirator my tongue falls less into my throat when I am on my side. Does anyone have other insights on this?

[JohnBFisher]

... I might speculate about some pathophysiology for this as follows: the respirator keeps the throat open and being on my back puts less pressure on my lungs; however, without the respirator my tongue falls less into my throat when I am on my side. Does anyone have other insights on this? ...

That's about correct - as far as O2 in the blood during night goes.

When you sleep on your back you probably place less load on both your lungs and heart. But when you sleep on your side you probably get more air more consistently into your lungs (it reduces the apnea events).

Unfortunately, without CPAP (respirator as you put it), you still stop breathing on your side. And that leads to severe problems with hypertension, can trigger diabetes (due to related weight gain), and can lead to heart failure and/or strokes.

So, at this time, the only known effective solutions (and certainly not a cure) for obstructive sleep apnea is to use CPAP. Though position helps it does not address all the problems.

[roster]

I am interested in the relationship between sleep position and SpO2. My doctor's advice had led me to believe that sleeping on my side was a way for me to address my OSA and so whether sleeping with a respirator or not I had been trying to sleep on my side. What I have found is that with respirator, I can get good SpO2 on my back (probably better than on my side), and I feel better skeletally, muscularly, and neurologically after a night on my back than a night on my side. Without a respirator, sleeping on my back is terrible for SpO2. For instance, two nights ago, I took off my mask in the middle of the night and slept without it on my back for several hours. My SpO2 suffered (several times below 87%). This night, I slept with my mask for 6 hours and another two hours without respirator on my side, and SpO2 stayed good while I was on my side. My tentative conclusion is that sleeping on my side helps SpO2 when I am without respirator, but that with respirator SpO2 on my back is better. I might speculate about some pathophysiology for this as follows: the respirator keeps the throat open and being on my back puts less pressure on my lungs; however, without the respirator my tongue falls less into my throat when I am on my side. Does anyone have other insights on this?

A couple of suggestions:

1)You complain about "skeletally, muscularly, and neurologically" when sleeping on your side. You might consider sleeping in the Falcon position (viewtopic.php?f=1&t=36738&st=0&sk=t&sd=a&start=15) which many people have found is the best position for comfort, especially comfort of the spine. Also, in the Falcon position, similar to a side position, gravity is not acting directly to pull the tongue into the airway. A potential side benefit is, if you have any aerophagia, you may find it is lessened or avoided by sleeping in the Falcon position.

2)For patients whose anatomy is such that the “tongue falling into the back of the throat” is part of their problem, many may find that a lower pressure is needed in the Falcon position or a side position. You may want to self-titrate your pressure separately in all three positions. I, for instance, found a large difference in pressure needs for backsleeping (requires higher pressure) as compared to Falcon position or side position. So I set a lower pressure and make sure to avoid backsleeping.

3)I am sure you did not relate all your analysis in just the above post. But just in case, let me mention that a couple of nights comparing SpO2 in sidesleeping position versus backsleeping position might not be statistically significant. Also, between the nights, there are likely many more variables changed than sleeping position. For instance there could be differences in unintentional mask leak, nasal congestion, digestive response to the day’s diet, exercise (or lack thereof), stress levels, room temperature, and 401k performance.

Good luck.

[harry33]

my sleep doc says everyone is different regarding their best sleeping position generally its best on side or sleeping sitting up in an armchair

[rada]

John, Roster, and Harry,
John, thanks for the feedback about the pathophysiology. The reason I said respirator rather than CPAP is that I use 'autoset with ERP' which remains unclear to me as to how it differs from biPAP and CPAP, but autoset, CPAP, and biPAP are all respirators. They all have positive pressure but differing amounts in differing patterns. Should I call my autoset simply CPAP? Back to the topic of position and respirator, under what conditions could a person reduce how much of their obstruction with position?
Roster, thank you for the pointer to the Falcon position description. I have now read that 4-page thread with wonderful descriptions from Dr. Falcon. I have tried sleeping in the prone position unsuccessfully. I had not heard of the half-Swastika position but will try it.
As I have been monitoring my sleep every day for months with a plethora of measurements, what I found an interesting anomaly which led to today's post about 'position and respirator' was this:
(a) on the back for me seems worse without respirator than on side without respirator, but
(b) on the back for me seems better with respirator than on side with respirator.
John and Roster may be suggesting that back would not be better with respirator. I have not looked deeply enough yet. John and Roster are suggesting that a person would need higher cmH2O from CPAP when on back. I agree that higher pressure is a disadvantage and will investigate that further.
Because of my radiation neuropathy to the spinal accessory nerve and brachial plexus, I met my physical therapist last week and asked her about the pros and cons of side versus back position for sleep, and the physical therapist recommended back over side for my musculoskeletal complications -- each of us has complications that add to Roster's list of diet, mask leak, 401K performance, and more.
Harry, thanks for the note about position.
Thanks,
Roy

[JohnBFisher]

... Should I call my autoset simply CPAP? ...

Your AutoSet II is an APAP unit, it automatically adjusts the Positive Airway Pressure.

... under what conditions could a person reduce how much of their obstruction with position? ...

Well, anytime you move about, differing amounts of stress, differing amounts of alcholol consumed, etc. all adds up to differing needs for pressure. That's the advantage of an APAP unit. It provides the pressure you need when you need it.

... (a) on the back for me seems worse without respirator than on side without respirator, ...

That's pretty normal.

... (b) on the back for me seems better with respirator than on side with respirator. ...

That's not as normal. But everyone is different. Your needs are not my needs.

... John ... may be suggesting that back would not be better with respirator. ...

Nope. Normally on your back you will have more apnea events than on your side. But you clearly don't follow that pattern. However, the APAP is adjusting to the pressure you need to minimize obstructive apneas.

... John ... are suggesting that a person would need higher cmH2O from CPAP when on back. ...

Yes. That's when most people have the greatest number of apnea events.

... I agree that higher pressure is a disadvantage and will investigate that further. ...

That's the advantage of APAP. It provides the pressure only when you need it.

... I met my physical therapist last week and asked her about the pros and cons of side versus back position for sleep, and the physical therapist recommended back over side for my musculoskeletal complications ...

So, it seems sleeping on your back would be better. So, I would use your AutoSet all the time (back or side) to be certain you breathe as well as possible.

[rada]

John (and at end Roster),
Last night was one of my best nights in years and the relatively homogeneously good data leaves little room for supporting some hypotheses about causality between treatment and result. However, I will try to map the pressures on back to those on side. By way of background the SpO2 was above 96% essentially all night and the AHI was 7 but % time in apnea only 0.1. According to webcam, I was on
• back from 00:43 till 3:05
• left side from 3:10 till 4:20
• back from 4:20 till 5:43
• right side 5:43 till 6:54
• back 6:54 till 8:10
• 8:10 till 9 a.m. in Falcon position without APAP.
I don't have yet an automated way to compute pressure averages over specified periods of time but will eye-ball my ResScan graphs to suggest average cmH2O during those periods as follows
• 9 cmH20 from 00:43 till 3:05
• 9 cmH20 from 3:10 till 4:20
• 10 cmH20 from 4:20 till 5:43
• 9.6 cmH20 from 5:43 till 6:54
• 9.2 cmH20 from 6:54 till 8:10
I would say some other factors would need to be considered to explain that data rather than simply 'back needs higher pressure', but I could see evidence in it for your hypothesis that back needs further pressure.
Average SpO2 % during that time I can get precisely using my computer program for computing averages that I posted a couple weeks ago:
• 96.7% back from 00:43 till 3:05
• 97.3% left side from 3:10 till 4:20
• 98.3% back from 4:20 till 5:43
• 97.6% right side 5:43 till 6:54
• 97.2% back 6:54 till 8:10
This data without further modeling and study also seems inadequate to shed much light on the hypothesis.
Also thanks for correction of terminology to APAP. The pull-down menu on the cpaptalk.com site called my machine autoset CPAP but I prefer APAP.
For ROSTER, I did for 40 minutes try the Falcon position. Eponyms are the bane of health care professionals. Let me say 'modified prone sleep position'. Anyhow, the position was reasonably comfortable and supported decent SpO2. However, I was surprised at the level of congestion and rise in pulse. Dr. Falcon uses antihistamine for the congestion that might increase in this position. Definitely, I will further experiment with the 'modified prone'.
Cheers,
Roy

[rada]

Last night was more interesting than the night before it. For starters the AHI was much higher and thus provides more data points -- notice also the plethora of 10-second apneas:

For another, I was experimenting with the modified prone position described elsewhere on this discussion board. My table titled "Summary of Activity for Feb 23" shows various data points throughout the sleep from 11:39 p.m. Feb 22 till 6:53 a.m. Feb. 23. The pressure and AHI seem to follow two phases -- lower in the first 3 hours and higher in the last 4 hours. SO2 was much worse without APAP from 6:21 till 6:53 a.m., but otherwise the averages hide the few spikes. A clear relationship between position and pressure is not obvious to me. In other words, whether I am sleeping on my left side (called 'left' in the table), on my back(called 'back' in the table), on my back with my head to the right (called 'head to right'), or in one of the modified prone positions (labeled with 'swastika'), the only clear pressure pattern seems to be that pressures were greater in the last half. In this one-night-sleep, the back position corresponded with a higher AHI than left-side sleeping.