Need Help With Numbers, Please

[LyricZ]

Hello, everyone.

6 Pt. Star very kindly showed me the article about how to retrieve my own numbers. Now that I have them, I need to know what they mean.

Here's what I have for my first night:

AHI 6.1
Leak 34.6

Please, someone, give me a clue. Where can I read an article on the numbers? Or can you give me a lesson?

Thanx

[bdp522]

For your AHI; anything under 5 is considered normal. Most of us like to see it lower, some of us get lots of 0.0, but so long as it's under 5 you're good.
Leaks mean loss of treatment. Masks come with a little chart that shows the exhaust leak rate. You want to be as close to that as possible. So if your leak rate is 36 and the exhaust leak is 25, you have a leak of 11. For me that's way too large a leak, if I can't get the leak rate within 3 or 4 of the exhaust leak rate I keep tweaking. Very large leaks will skew the data from the machine.

Brenda

[Snoredog]

the AHI number is the "avg" SUM of Apnea plus Hypopnea per hour.

In a person without OSA, they would have a AHI of less than 5 per hour. So that is the target we all try to shoot for, get our AHI down to what a normal person would have.

Getting that number down below 5 or in ideal therapy territory you increase pressure on the machine until it drops below that.

So if you are at 8.0 cm pressure, you would increase it to 9.0 and that AHI=6.1 should go down below 5 or closer to zero. It is very difficult if not near impossible to maintain a AHI=0, so if you can get it below 5 and maintain that night after night, you are getting ideal therapy.

Leak:
The leak number comes from the mask. There are two types of leak, intentional and unintentional. Intentional leak is the built-in leak rate into the mask in the form of exhaust. Your mask has this intentional leak so it can evacuate the CO2 you breathe out.

To determine if the leak rate you are looking at is high or low, you have to know what your mask intentional leak rate is. So with your mask comes a specification sheet usually containing a flow graph chart. You first find the pressure you are using on your machine, if its an auto it would be the 90% pressure. Once you know the pressure you are using, you find it on the mask chart.

So if you look on the chart and your pressure is 10 cm, it should give you a intentional leak rate. If your mask has a 28L/m leak rate at 10 cm pressure and the machine is telling you it is 34.6, then you subtract what the machine says from the value observed from the mask flow chart.

So yours might be:

34.6 (reported by the machine)
-28.0 (from the flow chart)
-------
=6.6 actual leak (external or unintentional leak between mask cushion and your face).

So if your resulting leak is 12 L/m or less you don't really have anything to worry about, but if it starts climbing higher you want to manage them better.

[RiverDave]

LyricZ,

bpd is right on. In case you can't find your manual, here are some key leak rates for the Quattro.

Pressure (cm H2) Vent Flow Rate (L/m)
4 22
8 32
12 41
16 48
20 54

Vent flow rate is also known as intentional leak rate or design leak rate

If you want the exact number, post your pressure and I will get it to you. One thing to keep in mind, however, is that the confidence ResMed has published for these number is plus or minus 6 L/min.

Good Luck,

[RiverDave]

Ok,

The forum doesn't like spaces, so:

Pressure = 4, leak = 22L/min
Pressure = 8, Leak = 32 L/min

etc

[Guest]

Please be patient with me, guys. This is not so simple for me.

The sleep doc said that she prescribed that the machine be set at 6. I don't know what that number means.

Then the machine says that it is 90% pressure. I do have it on auto.

Then my manual says "Mask Pressure" (cm H2O) and the scale goes up to 30.
The "Vent Flow Rate" (L/min) side of the graph and the numbers go up to 70.

Where should I see the 90% pressure? Or where do I find the mask pressure? I'm so confused. I do understand what you all have written, but I'm not sure how ...what the ...? I'm a bit slow.

Oh, wait!!! I looked at the graph again. See if this is correct.

So the number 6 that the doc mentioned is the Mask Pressure.
And the Vent Flow Rate for that number is I think 28.
My actual number for last night was 34.6, which I am going to round up to 35.
So I subtract 28 from 35 and get a sum of 7.
So I'm unintentionally leaking 7 liters of air per minute? Eh?

[Guest]

Also, if this is correct, is 7L/m too much? How close should it be intentional vent flow rate?

One more question, are the 4 blue lights supposed to stay on when the machine is off? I push the middle button to turn it off. Is there another button that turns the whole thing off completely? I really love seeing the blue lights, they're not bothering me. I just don't want to burn anything out by keeping it on constantly if it's supposed to be turned off some other way. I may have missed it, but I didn't see anything in the manual about this.
Thanx

[Guest]

Hi all,

Are there any books, wed sites that talks about sleep apnea's cpap treatment management that explans technical parts like AHI, Leaks, CPAP, APAP, BPR, etc? please help. thank you.

1)Books Titles/ISBN#
2)Web Sites.


mckooi

[RiverDave]

LyricZ,

I am assuming it is you who is posting as the first guest. If so, you got it!

If your 90% pressure is 6, then the intentional leak rate for your mask is 27.2. This would make your unwanted leak rate about 7.4. From what I have seen on the forum, that's not too bad. Ideally (and a challenge to achieve), you want this to be 0.

For comparison, I have managed to keep my weekly leak averages between 3 and 5 and have had zero leak rate 17% of the nights I have been using xpap.

Unfortunately, I use a different machine that yu, so I don't know about the lights.

Good luck,

[bdp522]

Here are some definitions from Snoredog;

Stuff seen on a PSG Report:

Arousal: An interruption of sleep lasting greater than 3 seconds.

BR Arousal index: The number of breathing related arousals(apnea, hypopnea, snoring & RERAs)multiplied by the # hours of sleep.

Bruxism: Grinding of the teeth.

Central apnea: A respiratory episode where there is no airflow and no effort to breathe lasting greater than 10 seconds.

EEG/EOG: Comments about sleep stages, brain waves (EEG), or eye movements (EOG)

EKG/ECG: Comments about heart rate, abnormal heart beats, etc.

EMG: Comments about leg movements and or teeth grinding (bruxism).

Hypopnea: A respiratory episode where there is partial obstruction of the airway lasting greater than 10 seconds. Also called partial apnea or hypo-apnea.

Non-supine: Sleeping in any position other than on the back.

NSR: Normal sinus rhythm.

NPSG: Nocturnal Polysomnogram, or sleep study.

(#)Number of Awakenings: The number of pages scored as wake after sleep onset.

Obstructive apnea: A respiratory episode where there is a complete cessation of airflow lasting greater than 10 seconds.
PLMs: Periodic limb movements.

PLM arousal index: The number of periodic limb movements that cause arousals multiplied by the number of hours of sleep.

PSGT: Polysomnographic technologist.

REM latency: Latency to REM(dreaming) from sleep onset.

RERAs: Respiratory effort related arousals. Episodes that are not apneas or hypopneas, often related to loud snoring, that generally do not cause a decrease in oxygen saturation.

Respiratory: Any specific comments about respiratory events.

RPSGT: Registered polysomnographic technologist.

Sleep efficiency: Total sleep time multiplied by time in bed.

Sleep latency: The first 30 seconds (one `epoch' of recording time) of sleep.

Sleep onset: The first 90 seconds (3 `epochs) of uninterrupted sleep.

Sleep stage shifts: The number of incidents of sleep stage changes.

Snoring intensity: Level of snoring loudness determined by the sleep technologist. Ranging in degrees from mild to very loud snoring.

Spontaneous arousal index: The number of spontaneous arousals (e.g. arousals not related to respiratory events, limb movements, snoring, etc) multiplied by the number of hours of sleep.

Stage 1: The lightest stage of sleep. Transitional stage from wake. top

Stage 1 shifts: The number of times the sleep stage changed to stage 1.

Stage 2: The first true stage of sleep.

Stages 3/4: The deepest, most restorative sleep.

Stage REM: The dreaming stage; Normally occurs every 60-90 minutes.

Supine: Sleeping on back.

Time in bed: The time in the study from `Lights Out' to `Lights On'.

Total arousal index: Total number of all arousals multiplied by the number of hours of sleep.

Total # of PLMs: The number of leg movements in sleep that last greater than 0.5 seconds.

Total sleep time: Total time asleep.

WASO: Wakefulness after sleep onset.

WNL: Within normal limits.

Brenda

[LyricZ]

Yes, that was me that posted as Guest. I used my laptop on that post, and forgot to log in.

Thank you all sooo much for helping me to understand. I've got it now. I'm going to print this out and keep it with all of my other info.

Thanks, bdp52, also for the further info.

You all have been so very helpful, and I appreciate your patience.

[Wulfman...]

If you haven't yet.....go up to the yellow lightbulb (Our Collective Wisdom) and start reading. Most of this information is in there, somewhere.....and, links to more information on the Internet.

There's a "learning curve" to this therapy, but it's like anything else.....if you want to learn more about it, the information is available.

It's YOUR therapy, YOUR health and YOUR life.....make the most of it.

Den

[debst99]

Just read a great book that someone here recommended. It was called Phantom of the Night-Sleep Apnea. This might help you understand some things also.