Sleep Study results-

[Alathea_Squared]

Can anyone help me interpret some of this? I guess my biggest question in all of this is 'is this apnea' or something else? I know the doc say OSA, but I was reading somewhere about how if your RDI was way higher than your AHI that there was something else that it could be "UARS" or something. It looks to me that there are no 'apneas' only disturbances. The chart at the end with the 'Events' seems to indicate otherwise.

1-Severe OSA
2-PLMS w/out arousals
Total sleep time 298 minutes


Sleep efficiency-61.8
AHI- 34.3/hr
RDI-50.4/hr
Respitory arousal index- 21.5

Number of arousals per 4.8 hours sleep time (pre treatment)-170
Arousal Index -34.2
PLMS Index 34.8
PLMS arousal index 2.1

Number of isolated limb movements 15
Isolated Movements with arousals-2

Lowest Sa02 level- 85
Percent time Sa02>89 73.3

Hypopnea Index 14.1
Hypop Arousals 0
Hypop Desats 70

No apneas/obstructive/central/mixed
AHI Supine 93
AHI non-supine 10

RERA index 8.5
RERA 42

[kteague]

Can you clarify for me that the limb movements mentioned were in your diagnostic study? What did they look like in your titration testing? Couple reasons for asking. Limb movements during a diagnostic study can at times interfere with apneas fully manifesting. The flip side is that apneas during a diagnostic study can interfere with limb movements fully manifesting if one happens to have Periodic Limb Movement Disorder (PLMD). I'm not familiar with what it might mean when the RDI is higher than the AHI. I look forward to reading input from others who might be more experienced in understanding results like yours.

[Pugsy]

Well I am totally confused here.

I see this

AHI- 34.3/hr

AHI being of course hourly index or average for Apneas + Hyponeas
and then I see this

Hypopnea Index 14.1

so that the Hyponea portion of the AHI. Then I see this

No apneas/obstructive/central/mixed
AHI Supine 93
AHI non-supine 10

So where is the other portion of the AHI? I assume the 93/10 is total over the night. Where is AI portion of the AHI?
Math tells me missing the 20.2 index for something which would normally be the Apnea Index. The respiratory arousal index is the closest at 21.5. Perhaps they are factoring in the RDI or Respiratory arousals somehow??? I can't get the math to compute.

Roughly 5 hours of sleep.

The mentioned graph image is missing. Could OP please try again to get the image to show. Perhaps that will shed some light on things.

Whatever though....still points to needing cpap. Even UARS is treated with cpap.

[turbosnore]

Couyld it be that the "No" here is an abbreviation of "Number", and AHI here could mean something like
"incidents" instead of "Index"?

I still can't figure out the maths here either.

[jamiswolf]

Alathea,
One thing that seems clear is that there's positional component to your apnea, So if you can train yourself to sleep on your side (as opposed to back), your apnea should be much easier to manage.
Jamis

[Alathea_Squared]

[avi123]

When I look at the Post Treatment column I see nothing out of the ordinary. I can't see their diagnosis and/or prescription if any. As to positional effect on events, most people have them to a certain degree.

[Alathea_Squared]

Diagnosis is severe OSA, prescribed a ResMed S9. My main curiosity was that there is an AHI/RDI, but no apneas listed, just the hypopneas.

[Pugsy]

Diagnosis is severe OSA, prescribed a ResMed S9. My main curiosity was that there is an AHI/RDI, but no apneas listed, just the hypopneas.

I can see where you would be curious. I can't get the usual math to compute here but the bottom line is that you did have enough Hyponeas (partial airway obstructions) to cause your Oxygen levels to drop to 85% and that is sure enough to warrant the diagnosis. Have enough Hyponeas back to back and they can actually be worse than one short lived apnea (full airway obstruction) with regards to the stress on the body.

Even if it was UARS, which is hard to define...treatment is still cpap.

As others have mentioned. There does seem to be a high degree of positional influence. The events are worse on your back. This is not unusual at all. Happens to a lot of people, very common in fact.
Minimal REM first sleep study and some REM second sleep study. Also makes sense. With the events causing arousals you never could really cycle into good REM stage sleep. Second study the events were treated well and you got into some REM.

Just because a person doesn't have many full grown apneas doesn't mean that the diagnosis is wrong. It just means you have enough Hyponeas to be as bad off as having full grown apneas. Bottom line is still the same.


Edit: Think of it this way. Which is worse on your body? A 10 second apnea (full obstruction) or two 45 second Hyponeas (partial obstruction) close together or back to back? What we don't see on these reports is how long the events lasted.

[stevos2000]

What I noticed in your results is that during the first part of your study, the diagnostic part, you didn't have any REM sleep. Typically, it is during REM sleep that your obstructive apneas would be much more likely to occur. Part of the reason for that might have been that your sleep was so fragmented with the various kinds of arousals and the strangeness of the whole sleep lab setting that you couldn't get into REM. Also, most REM periods typically tend to occur in the second part of the night. This is one of the flaws with the whole split night testing protocol. Still, the fact that you did have REM once you were under CPAP is a good indication that the CPAP treatment could be beneficial for you. Most of your problems seem to be positional in nature, so you might also consider other kinds of corrective measures, such as wedge shaped pillows and such

[Lizistired]

You should be getting some actual sleep by now. How do you feel?

[Alathea_Squared]

Im sleeping pretty well, when I get those 6 hours or so (after grad school study, kids to bed, DVR with the wife, etc) im actually sleeping, not wake/sleep/wake/sleep. Now i need to figure out if any of my VA medication for my lower spine/nerve injury is contributing to my difficulty with weight loss and/or contributing to OSA. I took Elevil in the Army for sleep difficulties but was never diagnosed OSA, then I got injured and discharged in 2002. I kept taking elevil until it ran out and then never refilled it-it made me a zombie. FF to now when im finding out that my spinal pain, depression, and fatigue are all tied together in some convoluted way.

[robysue]

Robysue the mathematician can explain the numbers!

The odd thing about the way the data is presented in this sleep study is that the event counts are for the total events for the entire night, some indices are computed for the whole night, some indices are computed for the diagnostic (pre-CPAP) part of the night, and some indices are computed for the treated (with CPAP) part of the night.

Alathea_Squared got right at 5 hours of sleep total. Of that, 122.5 minutes = 2.04 hours were in the diagnostic part of the test and 175.5 minutes = 2.93 hours were in the treated part of the test.

The respiratory event counts for the entire night were:

42 RERAs
70 Hypopneas with desaturation.

My guess is that the hypops with desat were probably scored under the AASM Recommended Standard; in that case they required at least a 4% drop in O2, but did not require an arousal. However, if a hypop has both an arousal AND at least a 4% drop in O2, it counts as a hypop with desat, not a hypop with arousal.

Now, the overall AHI = 70/5 = 14.1 and the overall RDI = (70+42)/5 = 112/5 = 22.4 (There's some roundoff here because the total sleep time is actually just a wee bit under 5 hours.)

But those mysterious and apparently implausible AHI figures listed in the Pre-Treatment column at the end of the table are based the 122.5 minutes = 2.04 hours of Pre-Treatment sleep. Of these 2.04 hours of sleep, 29% was supine. Hence the Pre-Treatment supine sleep totaled .29*2.04 = 0.59 hours. And that means 2.04-.59 = 1.45 hours of PRE-treatment sleep was non-supine. We can now apply a bit of old fashioned algebra to determine how many of the events happened in the Pre-Treatment part of the study and how many happened Post Treatment. To summarize the sleep times in the PRE-Treatment part of the test:

• 2.04 hours of total PRE-treatment sleep
• 1.45 hours of non-supine PRE-treatment sleep
• 0.59 hours of supine PRE-treatment sleep

Easy part first: Since the POST treatment AHI = 0.0, that means all 70 of the hypopneas with desat happened during the PRE-treatment part of the test. That means the PRE-treatment AHI's are calculated as follows:

• Pre-treatment AHI = 70/2.04 = 34.3
• Pre-treatment supine AHI = 93 means (# hypops supine)/.59 = 93, which implies (# hypops supine) = 93 * .59 = 55. In other words, of the 70 hypops recorded during the study, 55 of them happened during the 36 minutes of supine sleep in the PRE-treatment part of the test.
• Pre-treatment non-supine AHI = 10 means (# hypops non-supine)/1.45, which implies (# hypops nonsupine) = 10 * 1.45 = 15. In other words, of the 70 hypops recorded during the study, 15 of them happened during the 1.45 hours of non-supine sleep in the pre-Treatment part of the test.

The RDI numbers, which include the RERAs can be found by first determining the number of RERAs that occurred during the Post-treatment part of the test:

Post-Treatment RDI = 3.1 AND post-treatment AHI = 0.0 together imply that all the events in the numerator of the post-treatment RDI are RERAs. So we have: (# post-treatment RERAs)/2.93 = 3.1, which implies (# post-treatment RERAs) = 3.1 * 2.93 = 9 post-Treatment RERAs.

And since 9 of the 42 RERAs occurred in the post-Treatment part of the test, that means 42-9 = 33 RERAs occurred during the PRE-treatment part of the test. So the Pre-treatment RDI is computed as follows:

Pre-treatment RDI = (70 hypops + 33 RERAs)/2.04 = 103/2.04 = 50.5

Now the upshot of all this arithmetic? Here are the figures you want to think about as your diagnostic figures:

• 2.04 hours of sleep, with 0.59 hours supine and 0.0 hours REM
• 70 hypopneas with desat (most likely requiring at least a 4% drop in O2 levels); overall AHI = 70/2.04 = 34.3
  • 55 hypops with desat while sleeping on your back; supine AHI = 55/0.59 = 93
  • 15 hypops with desat while NOT sleeping on your back; nonsupine AHI = 10/1.45 = 10
  • No REM means No AHI index, with is reported as REM AHI = 0.0
  • NREM sleep time = 2.04, so NREM AHI = Overall AHI = 34.3, but it is rounded to 33
• 33 RERAs occurred during the pre-treatment period; hence pre-treatment RDI = (33+70)/2.04 = 50.4

Your diagnosis of severe sleep apnea was based on that Pre-Treatment AHI = 34.3. The fact that the events are all hypopneas with desaturation instead of apneas is not important in making the diagnosis. The fact that your RDI is much higher probably does indicate that you've also got some UARS going on, but keep in mind that many sleep docs view UARS and OSA as a continuum of sleep disordered breathing. In other words, think of the RERAs as "baby hypops" that may very well turn into real hypops (and those real hypops may turn into apneas) if you left your OSA untreated for a long enough period of time.

And, as pugsy points out, there appears to be a very significant positional component to your (untreated) apnea: It is far, far worse on your back than not on your back. But even the nonsupine AHI = 10 puts you in the middle of the mild OSA range.

[Alathea_Squared]

Thanks Roby! Wow. Ill have to digest this-it certainly is easier to read than the report they gave me. VA is great with treating, not so great always with explaining what they are doing.