No respiratory events but still lousy sleep

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
ohwhatanight
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Re: No respiratory events but still lousy sleep

Post by ohwhatanight » Fri Feb 24, 2012 9:13 am

I've been getting better (but still not great) sleep for the past couple of nights. My AHI is around 1.6 so I guess that is good, but they are sometimes clustered pretty close together so for those time periods my AHI is probably a lot higher (this is consistent with my original study where I had a total AHI of 8.7, but it an AHI of 76.4 when I was in REM sleep). I still think I am waking up more than I should but I had to stop turning off and on my machine because it was messing up the data that my DME was getting from me (over a modem). They only got one hour's worth of data one day when I had actually had 8 full hours. I've quit using the ramp altogether because at the lower pressure, I feel like I am suffocating.

I am considering getting a Zeo so I can see how much deeper sleep I am getting on a nightly basis. I've seen mixed reviews - especially about the false sleep readings when you are awake. If it accurately measures the deeper sleep, I can live with it being off on the other. Opinions/Advice?

I'm tolerating the CPAP better but called my DME today to see if I can try a nasal pillow instead since I am not thrilled with the mask I have and am getting a lot of leaks around my eyes which is causing really bad eye dryness all day. (I've watched the videos for fitting several times - I think the mask just doesn't fit my chubby face shape well.) I wake up with dents all over my face and strap marks even though I have it sitting pretty darn loose. If, I get a Zeo, I'd have to have a different mask since the one I have has a big old honkin' forehead piece.

The SleepyHead program is only showing about 3-4 RERAs a night so I figure that probably isn't a big deal, though I still don't know what these are exactly. I had a RERA index of .53 last night. Anyone know if that is good, bad or average? I am also confused about the Vibratory Snore #2 events. I have an average of 130 a night of those with a max around 40. Again, is this good, bad or average?

One more question - is it normal to have my respiratory rate all over the place? It looks like a crazy roller coaster ranging from 10-30 all night long with no consistent pattern. What is the significance of the resp. rate?

HoseCrusher
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Re: No respiratory events but still lousy sleep

Post by HoseCrusher » Fri Feb 24, 2012 5:34 pm

robysue wrote: But I'm not sure how an oximeter would help to detect wakes---particularly wakes that are NOT the result of an arousal caused by OSA.
Remember that a pulse oximeter records two channels of data. Oxygen saturation and pulse rate.

Arousals are frequently (always?) accompanied by a change in pulse rate. If the parameters are properly set, these can show up as pulse events.

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robysue
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Re: No respiratory events but still lousy sleep

Post by robysue » Fri Feb 24, 2012 6:23 pm

ohwhatanight wrote: I've quit using the ramp altogether because at the lower pressure, I feel like I am suffocating.
On the PR System One you should be able to INCREASE the beginning RAMP pressure from the PATIENT's set up menu. So if you want the ramp, but can't handle the low starting pressure, increase the starting ramp to maybe 1cm lower than your normal beginning pressure.
I am considering getting a Zeo so I can see how much deeper sleep I am getting on a nightly basis. I've seen mixed reviews - especially about the false sleep readings when you are awake. If it accurately measures the deeper sleep, I can live with it being off on the other. Opinions/Advice? (empahsis added)
My hands on experience with the Zeo indicates it is far, far more likely to misscore my REM or LIGHT as WAKE rather than the other way round. I often see "long wakes" in the Sleep graph that I know are not there because they don't correspond to any time I remember even vaguely as being awake or restless. So my take is either the zeo is misscoring REM/LIGHT as WAKE or I really am the weird insomniac who consistently OVERESTIMATES my total sleep time instead of underestimating it. (Studies have indeed shown that most chronic insomniacs pretty seriously underestimate their total sleep time and pretty seriously overestimate the amount of time they lie in bed awake. One major part of CBT for insomnia is to both learn AND accept this truth and then actually apply it in daily life when reflecting on the question of "how much sleep did I get?" each morning.)

And near as I can tell my Zeo seems to score Stage 3 (Deep) pretty accurately.

I'm also learning to put together the Zeo data AND the wave flow data in SH to get a pretty good idea of just when the zeo has seriously misscored something. Sleep breathing once you're getting quality sleep is much more regular than wake breathing and once you get used to zooming in on the wave forms to the point where you can see five minutes worth of the individual breaths, it's not that difficult to pin-point when something is markedly different or weird. Sometimes, of course, the weirdness is easy to associate with OSA events. But sometimes it's out of the blue and that usually indicates (for me) a wakeful/restless period that is usually picked up by the zeo unless it is very short. The Zeo doesn't tend to pick up extremely short arousals----the device just isn't that sensitive and it lacks an EEG sensor on the BACK of your head, which seems to be important in picking up arousals---at least according to what someone at Zeo was telling my hubby the other day. (Hubby has a professional interest in modeling sleep cycle data using something called a hidden Markov model. So once I got my Zeo, he started contacting folks at zeo; eventually he got lucky and managed to get an email and phone conversation with someone there who knows something about the particulars of how the Zeo works.)
The SleepyHead program is only showing about 3-4 RERAs a night so I figure that probably isn't a big deal, though I still don't know what these are exactly. I had a RERA index of .53 last night. Anyone know if that is good, bad or average?
RERAs on a sleep study are best understood as arousals that follow evidence of increasing respiratory effort---i.e. you arouse yourself to fix the breathing before the situation is "bad enough" to be flagged as a hypopnea or an apnea. They go into the RDI and if you have lots of them you can still wind up with a diagnosis that leads to CPAP therapy even if you have no hypopneas or apneas at all.

RERAs scored by the System One are based on a proprietary algorithm. PR has studied the wave forms from many, many PSGs and they think they've identified characteristics in the wave flow that indicate a high probability that a PSG RERA has occurred based on the shape of the wave flow. When I look at RERAs scored by my machine, sometimes I can spot a a bit of ever so slightly ragged breathing followed by a sudden deep inhale (a recovery breath) and sometimes I can't see a damn thing suspicious in the data. If you're only getting 3 or 4 RERAs a night, then forget about them for now.
I am also confused about the Vibratory Snore #2 events. I have an average of 130 a night of those with a max around 40. Again, is this good, bad or average?
Snoring is something I've not yet figured out on the System One. My own snores are split into VS #2's and VS #1's because I'm running in AUTO mode. (The VS #1's increase pressure, the VS #2's don't.) What the heck the criteria for scoring a VS #1 or a VS #2 is seems to be a mystery. My own snoring numbers bounce around rather dramatically. I'll have several nights in a row where there are less than 10 or 20 VS#2. And then I'll have a monster night with 50 or more. Last spring during tree pollen season, I'd have nights where there were over 100 VS2's, but not many. I've also noticed that my VS#1 and VS#2 numbers and indices in SH appear to have little in common with the VSI as reported in Encore Viewer. And half the time when the machine says I'm snoring, hubby says he heard nothing. And sometimes hubby says he hears snoring and the machine didn't pick it up. (Maybe he heard his own snoring, which is highly intermittent, not bad on a nightly basis, but can get really awful every now and then.)

My guesses:

1) Snoring is considered a "precursor" to OSA events---i.e. where there's snoring, there's evidence that the upper airway may be compromised and more prone to collapse. And that's why it's scored. Snoring can also cause arousals of the person doing the snoring. And you may or may not remember the arousal. Or you may or may not remember the snoring that lead to the arousal---i.e. you may remember waking up, but not remember that it was your own snoring that woke you up. You might want to call the sleep doc's office and ask what the snoring numbers looked like in Encore and whether the sleep doc is worried about them.

2) The pattern of the snoring may also be important. Some folks have reported that the System One is prone to scoring VS2's when there's no snoring going on. The hose rubbing against the table edge is thought to be a culprit by some folks.

3) No-one really knows what the scale on the snoring graph represents---this graph is NOT available in Encore Viewer or Encore Pro. But it's there in the data. Our best guess is that larger numbers indicate louder snoring. What is "roof-raising" snoring? I don't know. My own snoring on my PSG was described as "soft snoring". On my worst nights, I sometimes see the snore graph get peaks up between 20 and 30. I don't know what my highest snore graph value is right off the top of my head.

4) Some folks have more problems snoring when on their backs. Some folks have more problems with their snoring when they are also fighting nasal congestion. So those are two other things to consider about the snoring.

5) If you want to try a small increase in pressure to see if that brings the snoring numbers down, then you might eliminate one more source of wakefulness.
One more question - is it normal to have my respiratory rate all over the place? It looks like a crazy roller coaster ranging from 10-30 all night long with no consistent pattern. What is the significance of the resp. rate?
The respiratory rate is the number of breaths you are taking each minute. Average at rest (while awake) respiratory rates for healthy adults are usually reported to be somewhere in range of 10-20 breaths. (Different sources will cite different "average rate" ranges that are tighter than what I've given. But this range seems to encompass all of the ones I'm familiar with.) In sleep, the average respiratory rate for adults seems to be in the lower half of that range: Most typically it's reported to be somewhere between 12 and 16 breaths per minute.

The respiratory rate should not look like a crazy roller coaster. But when I go back and look at my early data, there's a lot of crazy roller coaster mixed in to it and many of those nights are the "really rough" nights according to my journal. My guess as a patient who has been there and done that: Some of that roller coaster is simply due to anxiety, which can often trigger rapid breathing, and some of the roller coaster stuff may be due to restless sleep. Wakeful breathing is not as regular as normal nighttime breathing is supposed to be and so when you're restless and moving in and out of WAKE and light sleep, there's going to be more variation in the respiratory rate than when you are sound asleep.

It's not that normal sleep breathing will have a completely constant respiratory rate, but it will pretty much stay in a rather small range and not bounce around that much. When I'm sleeping well, my respiratory rate typically stays between 10 and 15 for most of the night, for example, and most of the changes are gradual rather than sudden jumps. When I'm sleeping poorly, there's more variability: It may peak above 15 far more often and even when it doesn't it will more rapidly go from 10 to 15 rather than very slowly increasing or slowly decreasing. Other things that affect the respiratory rate on a short term basis include: changes in sleep stage and moving around in bed. When you change sleep stages, there can be a change in the respiratory rate, but it shouldn't look like a roller coaster. And when you start moving around in bed the respiratory rate can go up as well.

So my guess is that most (or all) of that roller coaster respiratory rate is just you figuring out how to breath with the machine. And I think I've read somewhere that some folks tend to hyperventilate a bit (high respiratory rate) when they start CPAP; it could just be part of the acclimation process, or it could be triggered (or at least aggravated) by anxiety and worry.

So for NOW, I'd recommend that you not worry at all about the respiratory rate. What you need to focus on is teaching yourself how to sleep well and how to sleep with a six foot hose on your nose. Don't give yourself more things to worry about just yet.

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deltadave
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Re: No respiratory events but still lousy sleep

Post by deltadave » Fri Feb 24, 2012 7:12 pm

robysue wrote:The Zeo doesn't tend to pick up extremely short arousals----the device just isn't that sensitive and it lacks an EEG sensor on the BACK of your head, which seems to be important in picking up arousals---at least according to what someone at Zeo was telling my hubby the other day.
Electrodes at the back of the head (occipital) are used to differentiate Wake from Sleep. Arousals are scored from electrodes on the top of the head (central) although interestingly, O’Malley et al showed improved detection of cortical arousal following obstructive respiratory events using frontal leads.

Whoa. I see ol' Dave and Bob came up there, too.

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ohwhatanight
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Re: No respiratory events but still lousy sleep

Post by ohwhatanight » Fri Feb 24, 2012 7:33 pm

Thanks for all the nice detailed answers. I think I will wait a while before getting a Zeo - right now it would probably just add more anxiety as one more thing for me to analyze to death. I had a pretty decent night last night (finally) without all the usual anxiety about whether or not I would get enough sleep, so I guess I need to go with that for a while. I'm still really exhausted during the day but I think I have a heck of a lot of sleep debt to make up for. Also, air leaks around my eyes is making them really dry and tired during the day so that may make me feel sleepier than I really am. Hopefully that will be taken care of with a new mask (if I can ever get one!)

I think you are probably right about the respiratory rate roller coaster being related to me just getting used to the whole thing. I'll compare in a few weeks and see if it settles down some. The same for the snoring - it isn't bothering anyone else right now and I don't seem to be waking up (that I am aware of) at the same times it looks to be the loudest. My doctor said she didn't have my snore data, which seemed odd to me, so I doubt she will raise my pressure yet.