Understanding a Sleep Study

Below is information I just found on a web site. I hope it's not illegal to post this info on this forum, but as a "newbie", I found this information very helpful and thought others might also.


UNDERSTANDING A SLEEP STUDY

1. RESPIRATORY EVENT: ONE OF FOUR BREATHING DISTURBANCES THAT MAY OCCUR DURING SLEEP INCLUDING CENTRAL APNEA, OBSTRUCTIVE APNEA, MIXED APNEA, AND HYPOPNEA.


2. OBSTRUCTIVE APNEA: A PERIOD OF 10 SECONDS OR MORE, NO AIRFLOW IS MEASURED AT THE NOSE AND MOUTH BUT ATTEMPTS TO BREATHE CONTINUE (BREATHING ATTEMPTS ARE DETECTED BY THE BELTS AROUND THE CHEST AND STOMACH).


3. CENTRAL APNEA: A PERIOD OF 10 SECONDS OR MORE, WHEN THERE IS NO AIRFLOW MEASURED AT THE NOSE AND MOUTH, AND THERE ARE NO ATTEMPTS TO BREATHE DETECTED (A FEW OF THESE OCCURRING WHEN FIRST FALLING ASLEEP CAN BE NORMAL).


4. APNEA/HYPOPNEA INDEX: THE NUMBER OF RESPIRATORY EVENTS THAT OCCUR PER HOUR OF SLEEP (AVERAGED OUT OVER AN ENTIRE NIGHT OF SLEEP).


5. MIXED APNEA: A COMBINATION (OR MIX), OF A CENTRAL APNEA THAT TURNS INTO AN OBSTRUCTIVE APNEA.


6. HYPOPNEA: A PERIOD OF 10 SECONDS OR MORE WHEN REDUCED AIRFLOW IS MEASURED AT THE NOSE AND MOUTH, WHILE ATTEMPTS TO BREATHE CONTINUE. THERE CAN BE A 4% DECREASE IN 02 SATURATION.


7. Sa02: THIS ABBREVIATION STANDS FOR BLOOD OXYGEN SATURATION AND IS EXPRESSED IN PERCENT. NORMAL Sa02 = 90% OR HIGHER


8. PERIODIC LIMB MOVEMENT INDEX: THE NUMBER OF LEG MOVEMENTS THAT OCCUR PER HOUR OF SLEEP (AVERAGED OUT OVER AN ENTIRE NIGHT OF SLEEP).


9. PERIODIC LIMB MOVEMENT INDEX WITH AROUSAL: THE NUMBER OF LEG MOVEMENTS THAT OCCUR PER HOUR OF SLEEP WHICH, CAUSE DISRUPTION TO THE SLEEP (AVERAGED OUT OVER AN ENTIRE NIGHT OF SLEEP).


10. HEART RATE: THE NUMBER OF TIMES THE HEART BEATS PER MINUTE (NORMAL RANGE = 60-100).


11. AROUSAL: AN INTERRUPTION OF SLEEP, WHICH MAY OCCUR FOR A VARIETY OF REASONS (RESPIRATORY EVENT, LIMB MOVEMENT, SNORING, LOUD NOISE, NO APPARENT REASON, ETC).


12. STAGE 1 SLEEP: THE LIGHTEST SLEEP, WHICH NORMALLY OCCURS FOR A FEW MINUTES WHEN FIRST FALLING ASLEEP. STAGE 1 IS OFTEN SEEN AFTER AN AROUSAL OCCURS. NORMAL AMOUNT IS APPROXIMATELY 6% BUT VARIES WITH AGE.


13. STAGE 2 SLEEP: A DEEPER SLEEP THAN STAGE 1. NORMAL AMOUNT IS APPROXIMATELY 40-60% BUT VARIES WITH AGE.


14. STAGE 3-4 SLEEP: THE HEAVIEST OR DEEPEST SLEEP. NORMAL AMOUNTS OF THIS SLEEP CAN INCLUDE FROM 0-26% BUT VARIES WITH AGE.


15. REM SLEEP: STANDS FOR RAPID EYE MOVEMENT SLEEP (DREAMING). NORMAL AMOUNT IS APPROXIMATELY 20% HUT VARIES WITH AGE.


16. SLEEP EFFICIENCY: THE AMOUNT OF TIME DURING A SLEEP STUDY THAT IS ACTUALLY SPENT ASLEEP (EXPRESSED AS A PERCENTAGE OF TOTAL TIME IN BED).


17. REM LATENCY: THE AMOUNT OF TIME IT TAKES TO START DREAMING FROM THE TIME ONE FALLS ASLEEP. NORMAL REM LATENCY IS ABOUT 90 MINUTES BUT VARIES WITH AGE.

Connie

Hi Connie,

Your post is fantactic. Very nice job. This is extremely usefull information for all.

THANK YOU!!!

Ted

Ted,

You've got that right! awesome! ...Thanks Connie!

I would love to know how I scored in many of these catagories during my two sleep studies.

All I was told was my AHI and my titrated pressure.

I'm going to have to get pushy and get a copy fo my results.

Wading,

You are entitled to the same report the physicial gets from the scoring tech. You may not get the sleep tech's notes from that night, but you will get the scoring tech's summary and supporting evidence of why they made the descision.

T

All of the above is interesting.

At the followup visit to the doctor after the sleep test, he went over the report some, but not all of it, and of course I forgot some of it. Would you believe I asked for his pen so I could jot down a couple of the numbers of the report and he looked at me like I was out of my mind?! So I pushed for him to have a copy of the test result report made for me. I'm glad I did. But, he had showed me more pages, which included interesting graphs monitoring the sleep during the test. He copied some of the pages for me, but not all of it, including the graphs. (I didn't realize this until I got home). That @#$%$## doctor must have thought that this was too much info for a woman to worry about! I'm going to call and ask for the rest. The graphs really are interesting.


Can anyone tell me what a bad oxygen level is? From the above post, it seems 90% is normal, I think. Do you know what the percentage means? Unfortunately, the % typed on my report got smudged in the copying and I can't read it. But I swear to god the doctor said I had 50% oxygen. My god, does that mean I'm walking around with half my oxygen? Is it so bad I should be rushed to a hospital? (I am out of breath alot). ....... Also, my AHI was 45.5 per hour. Is that typical, or even higher than most? The doctor said I had severe apnea, but I still don't how severe is severe. ......Oh dear, I'm hyperventilating just thinking about this!

Thanks.

Linda

Hi Linda,

As far as oxygen saturation, you should have 90 and above. Anything below 90 is concidered abnormal. I have a friend that dropped down to 50%, and the doctor told him that 20 years of this, he was lucky that he didn't have a stroke or heart attack.

The good news is that once you use the hose, you correct the issue. It is that easy. Also, if you have high blood pressure, you will get that more in line as well.

Good things are to come for you... Just make sure to use the pap.

Good Sleep,

Ted

Ted,

Then the doctor probably did say 50%. He did say that it took a high level of pressure through that cpap thing (during sleep test) to open me up and eliminate most of the incidents.

I'm so anxious to get started with the treatment, given how I feel. It's frustrating being told it will likely take a week or more before I get started. ..... I told God that if I could just get one decent nite of sleep and any improvement in this oxygen level, all by Christmas, ....I promise one major good deed....

Thanks.

Linda

Linda, what pressure did the doctor say he was going to prescribe for you?

Hi Rested Gal,

Thanks for asking. The doctor didn't say, but I just looked at the copy of the test report and it said that I would "benefit from the use of BiPAP at a pressure of 18/14 cmH2O". It went on to suggest the ramp (which I know what that is thanks to this forum) and a humidifier. Is this high? And does the "cmH2o" mean anything?

I'm most grateful for answers. Thanks so much.

Linda

Hi Linda,

"cm H2O" is simply the way cpap pressure is measured...the force of air it takes to raise a column of water so many centimeters. "cm" is a shorthand way to talk about cpap pressure settings. 18 cm or 14 cm. etc.

Apparently 18 is the pressure your machine will be set to blow at you while you inhale. 18 is a high pressure...can be hard to breathe against. So, your BiPap machine will be set to drop that pressure down to 14 each time you exhale, making it easier for you to breathe out against a little less pressure. 18/14 = 18 for inhalation, 14 for exhalation.

At that high a pressure, I (I'm not a doctor!!) really would recommend either the Activa nasal mask (covers the nose) or the Breeze with nasal pillows. If you choose the Breeze, be sure to get pillows that the DME would probably say are "too large" for you. Either of those interfaces can handle high pressures well with the least chance of leaking or having to be worn tightly. I think a cheapie mask like what the DME is probably going to try to get you to accept would be a leaky, nose bruising disaster. Also, be sure that they give you a heated humidifier - not just a "passive", "passover", or "cold" humidifier.

Oh thanks so much!

That tells me alot, and helps me when I make those arrangements.

Do insurance companies fight the additions or substitutions you describe? Or will I likely just pay more out of my pocket? Also, my sleep/cpap test was with pure oxygen added. The test report doesn't mention additional oxygen. The doctor said I would probably need it, but he wasn't sure yet whether to add it first or wait until I use just the forced air. I only remember from that bizarre sleep test (I had the half nite tests, the two in one), the technician started with just fresh air. But she quickly added oxygen from that big scary oxygen tank. I only know is that once she started that I was more uncomfortable. I guess it was likely because of the increased levels of pressure tested. And the air with oxygen was so cold to the throat. (wasn't as cold when starting with just air).

I'm not wild about this doctor, but he's all I can do for now. You know, I made the mistake of telling him I had been browsing the internet (I didn't mentoin the forum) to learn more. I got such a negative response from him. I could have decked him. What nerve saying nothing good could be learned from the internet! The internet and this forum are more of a lifeline to us than he cares to know. My primary care physician, however, always points me to the internet to get information on everything. What difference doctors make!

Your knowledge (perhaps you should be a doctor) and help is such a relief!

Linda

Oh, Linda...I just thought of one thing that would not be in favor of the Activa mask since you'll be using a BiPap. The reason the Activa seals so well against leaks and can be worn with straps very loose (even at high pressure) is because of its unique "bellows" cushion. But that very good feature tends to make the Activa move up and down on your face as you breathe and the airflow changes slightly inside the mask. (I've heard it described as being like a lovesick octupus doing pushups on your face. heheh) I notice it as a slight movement - easy to get used to - as I breathe with my autopap. But that movement is magnified a lot for people on BiPaps....a greater change in pressure inside the mask with every breath moves the Activa up and down more. Might not bother some people, but annoy others intolerably. So, the Breeze with nasal pillows might be the better interface for you to get.

The Breeze and the Swift are two very good "nasal pillows" interfaces. If you prefer to sleep on your side, I'd go for the Breeze. If you prefer to sleep on your back, definitely the Swift (but it's noisier than the Breeze.)

I've always just bought my stuff online out of pocket - never had to deal with insurance or DME issues myself. So I guess it would depend on the individual's local DME and insurance policy as to how hard it is to get what you want or need.

Loved the "lovesick octupus" description.

Yes, I'm a side sleeper, definitely not a back sleeper. About the Breeze with nose pillows.....I guess I don't understand them although I see people talking about them. Is it a nose mask like the others but with these pillows in your nose to take the brunt of the air pressure? Are they easy to get used to?

Also, you said BiPAP. What's that versus cpap? Is that with the added oxygen?

Funny, but the doc says my test results showed I slept fine with the high pressure and nose mask. But I remember the end of the test fighting with the mask to get it hold the pressure. It kept moving and leaking, making me cry and wonder how one keeps this thing on comfortably. Maybe I was sleeping OK at first with the high pressure, but the last of the high pressure was finally wreeking havoc on me and my mask.

Thanks hugely.

Linda

Hi Linda,

You've had lots of great questions and rested gal has great answers doesn't she.

My turn though - Bi-pap is just like a cpap only while the "C" stand for constant pressure the "Bi" stands for two pressures. One on inhalation and on on exhalation. These are used for people on higher pressures. your inhalation pressure of 18cm is at the high end of the usual 4cm to 20cm range.

FYI an auto-pap (which I have) automaticaly senses what pressure you require to keep you airway open and adjusts accordingly.

The added oxygen is not referenced in any of these names.

The nasal pillows are little soft plastic bellows about the size and shape of a hershey's kiss except not as pointy. At the small end they have a hole and the thicker end seats against your nostrel to seal out any leaks. Two pillows fit into a chamber that the hose connects to. The head gear holds the chamber in the right place and seats the pillows into your nose.

So I guess your choice is a love sick octopus or two hershey's kisses up your nose

Actually both of the systems the Activa and the Breeze are much better than the others out there.

The added oxygen can really dry you out so maybe you won't need it for long if you do.

Keep asking those great questions