CompSA, Hypoventilation, PLMs, Bradycardia and Hypotension?

[Muffy]

I think it's academic.

Meaning a challenge by any set of scoring standards...?

Well first, we have to make sure that apneas are scored correctly (hypopnea rule will come into play in a moment).

AASM says:

A thermistor is recommended for detection of the absence of airflow for the purpose of identifying apneas. A nasal pressure transducer with or without square root transformation of the signal is recommended for the detection of a flow reduction for the purpose of identifying hypopneas. As indicated in the scoring manual review paper, J Clin Sleep Med 2007; 3:169/, use of only a nasal pressure transducer can result in misclassification of hypopneas as apneas.

http://www.aasmnet.org/FAQs.aspx?cid=29

So if the thermistor needs to be the channel to score apneas, then how many apneas are there, and of those, how many are obstructive?

Muffy

[-SWS]

According to this chart, it's all a matter of simple yes-or-no questions (or in one apparent typo, no-or-no questions) once you do CPAP and a follow-up Epworth.

I had no idea it was all supposed to be this simple!:

If I understand the process correctly, we take the flowchart home, plug it into the wall, and we're good to go! They're available down at Staples Office Supply... right next to the red buttons:

[Muffy]

So if the thermistor needs to be the channel to score apneas, then how many apneas are there, and of those, how many are obstructive?

And you can't count that one, cause it's only 7.6 seconds long:



Muffy

[jnk]

Does is count against us if we guess wrong? Or do we get credit just for trying? And do you promise not to yell at me?

'Cause with the dancing belts, I'm guessing obstructive, and with the dancing thermo-thingy, I'm guessing hypopneas maybe?

Besides, I hear that UARS has been cancelled due to lack of interest.

Please don't fire me. It's my first day. And I cry easy.

jeff

[SleepingUgly]

Muffy, when you score hypopneas, do you use the Chicago Criteria, the AASM Recommended, or the AASM Alternative criteria?

I think it's academic.

What would you use here?

Well, at the top I see is a maximum security prison that was heavy-handed with the barbed wire. Just under that I see minimum security, possibly even a half-way house. Just under that, I see medium security prison. In the first prison, the felonies were hard cord and these guys are not getting out soon. Those in the minimum security prison are fairly petty crimes, and they'll be out and back to no good in no time. The medium security prison is where there's more trouble. I might ask to keep the inmate cuffed and I will definitely keep my back against the wall. I wouldn't wear necklaces, skirts, or high heels. Is this what you meant???

Thanks for asking my opinion on this, Muffy. It means a lot to me that you think I could best decide what criteria should be used. Here is my opinion: If you're going to use the AASM Recommended criteria, you must be satisfied with a high false negative rate. There will be people that, thanks to you, will remain symptomatic with no AASM recommended diagnosis. If you use the Chicago Criteria, you may have a higher false positive rate, but your false negative rate is low, so you're not missing many people who have SDB. In someone who has no sleep complaints, no oxygen desaturations, no EDS, the standard can be more stringent. In someone with significant EDS and other problems, you want to make sure you capture any disorder that might be lurking, so I'd use the Chicago Criteria. I would never require a desaturation to score a hypopnea because many thin people don't desaturate. An arousal instead of desaturation should be enough. One day a change in blood pressure will be enough. For today I'll accept an arousal.

So, what do you mean about it being academic? WHAT CRITERIA DO YOU USE TO SCORE HYPOPNEAS? (I just know he's going to answer me this time...)

[jnk]

WHAT CRITERIA DO YOU USE TO SCORE HYPOPNEAS?

I still believe that the answer is that you use whichever criteria each individual sleep doc tells you to use, if he/she has a preference.

But I'm going to bed before I fail the flowchart and mess up my Epworth for tomorrow. Good night!

[unadog]

Please don't fire me. It's my first day. And I cry easy

Stop it JNK! Stop it! They **like it** when you cry!

It is supposed to mean something to them, or something like that, to girls at least.

Don't you remember that massage thread? Gave me the creeps .... rubbing and all ...

So I vote for a massage. A person has to be slightly deranged anyway to acquiesce to getting naked and paying a stranger to rub them while soft music plays in the background... (I mean, how did that get to be socially acceptable, not to mention legal?!) Also, if he has a good cry during the massage, the massage therapist will be very flattered that the massage was so incredible as to bring him to tears. At the end, -SWS can hug the massage therapist with one hand (while hopefully holding on to the towel with the other).

This is where it happens, in the secret prisons. I kind of thought that was where we were headed when we started out in the black helicoptors:

The medium security prison is where there's more trouble. I might ask to keep the inmate cuffed and I will definitely keep my back against the wall. I wouldn't wear necklaces, skirts, or high heels. Is this what you meant?

Off to secret prisons, where they handcuff you and give you a massage! Like the lady says, jnk: Keep your back to the wall, especially if they make you wear a skirt!

Brings new meaning to the term "BFF". But I kind of thought our whole culture was heading in that direction ...

("cell phone died during posting" edit ....)

[-SWS]

Right before the limb movement... does that constitute a 90% amplitude reduction for at least 10 seconds on the thermocouple line? Nasal pressure is pretty flat for an extended period in that segment as well.

Unadog, I was downright pleased with my massage experience... I felt as if I was living inside the very experiential song itself by James Brown---thanks to that ChancellorJNK/SleepingUgly prescription.

Muffy, so you rightly take issue with the apnea scoring. But how about the hypopneas?

[Muffy]

Right before the limb movement... does that constitute a 90% amplitude reduction for at least 10 seconds on the thermocouple line? Nasal pressure is pretty flat for an extended period in that segment as well.

Right. That one (in 60-second view):



and the one I had marked are the only ones I believe qualify for discussion (HOLD THAT THOUGHT!) as obstructive apneas. The other events are either central, too short or hypopneas.

Muffy, so you rightly take issue with the apnea scoring. But how about the hypopneas?

OK, so now we need rules. Although we don't NEED anything, because we have raw data to work with. But for arguements sake, lets get the hyponea-defining stuff...

[Muffy]

...so let's look grossly (30 minute view)(BTW, it would certainly be helpful to do this live to see the differences as we pass from 30 second to 1, 5, 10, 30 minute views and more, but the time frame is noted at the bottom of the epoch, and when in doubt, count up the respiratory rate. ~12 breaths = a minute (assuming he's breathing).

ANYWAY....



If we're going to score hypopneas, we need to know the desats.

Muffy

[Muffy]

Oh, right, REM.

Everybody wants to see REM.

So there's bbREM:





Muffy

[Muffy]

Are those piezo or RIP belts?

Muffy

[blizzardboy]

Are those piezo or RIP belts?

Not sure Muffy. If they are easy to differentiate visually I could try and tell from the video files. Are you referring to the sensors that measured thoracic and abnominal effort? I'm loving the images! Cheers,

[SleepingUgly]

From:
Ruehland, et al. (2009). The New AASM Criteria for Scoring Hypopneas: Impact on the Apnea Hyopnea Index. Sleep, 32(2), 150-157.

In 1999, the American Academy of Sleep Medicine (AASM) produced a consensus report... These guidelines (also known as “Chicago Criteria”) described 2 types of hypopneas: (i) Those with a > 50% decrease in a valid measure of airflow without a requirement for associated oxygen desaturation or arousal, and (ii) Those with a lesser airflow reduction in association with oxygen desaturation of > 3% or an arousal...

in 2001...the AASM, via the Clinical Practices Review Committee, published a position paper which described a hypopnea as an abnormal respiratory event lasting ≥ 10 sec with ≥ 30% reduction in thoracoabdominal movement or airflow, and with ≥ 4% oxygen desaturation. This is currently the approved hypopnea definition for the Centers for Medicare and Medicaid Services in the United States to determine eligibility for treatment funding.

Nevertheless, in 2005 the AASM, via the Practice Parameters Committee, reported that, “Several clinical definitions of hypopnea are in clinical use and there is no clear consensus.” In a further attempt to improve standardization, the AASM recently published the Manual for the Scoring of Sleep and Associated Events. In this manual there is a “recommended” and an “alternative” hypopnea definition; and either can be used at the discretion of the clinician or investigator. The recommended definition is the same as the definition published in the AASM 2001 position paper: hypopnea scoring requires ≥ 30% reduction in nasal pressure signal excursions from baseline and associated ≥ 4% desaturation from pre-event baseline. The alternative definition requires ≥ 50% reduction in nasal pressure signal excursions and associated ≥ 3% desaturation or arousal.

If we're going to score hypopneas, we need to know the desats.

Ergo, Muffy is using the AASM Recommended criteria.

BTW, this is an interesting article because it shows that impact definitions of hypopneas have on the AHI and therefore on diagnosis of OSA. e.g.:

Using AHIRec, 36%, 43%, and 48% of patients previously classified as positive for OSA using AHIChicago would now be negative with AHI cut-offs of 5, 15, and 30/h, respectively. Using AHIAlt, 17%, 26%, and 25% of patients previously classified as positive for OSA using AHIChicago would now be negative.

Here is a link to the article:
http://www.journalsleep.org/ViewAbstract.aspx?pid=27368

[Rebecca R]

Well, at the top I see is a maximum security prison that was heavy-handed with the barbed wire. Just under that I see minimum security, possibly even a half-way house. Just under that, I see medium security prison. In the first prison, the felonies were hard cord and these guys are not getting out soon. Those in the minimum security prison are fairly petty crimes, and they'll be out and back to no good in no time. The medium security prison is where there's more trouble. I might ask to keep the inmate cuffed and I will definitely keep my back against the wall. I wouldn't wear necklaces, skirts, or high heels. Is this what you meant???

Hmmm…I think you might have mixed up the questions on the first part of the exam SU. Perhaps you thought you were answering this page.


Since we all agree that the internet is the best place for medical advice, it is cheaper to take the internet version of the test: http://theinkblot.com/


P.S. I'm requesting an exemption 'cause the dog ate my homework again.