What is a normal leak rate and AHI rate?

Hi...I've been on CPAP since 1993 and have been tolerating it well. I recently got a new machine that keeps track of everything (Respir. m series pro). I've had it a little over one week now and it is showing a leak rate of 24L/min and my AHI average is 3.6. What is a normal or an acceptable leak rate and AHI #? Thank you

A "normal" or acceptable leak rate depends on your pressure(s) and your mask. In the User's Guide that came with your mask is a graph showing what vent rate will be compensated for by the machine with that mask at your pressure.

I see you have the Swift LT. I have that as well. I have my auto set at a pressure range but my 90% pressure is 12 cm. If I look at the graph, I see that the machine will compensate for a leak rate of about 33 L/m on my machine at that pressure using that mask. That's about what my leak rate is when I look at my smart card data each time. If it's at or very near 33 L/m, I know that my leak rate is good. You need to compare your pressure with the graph to see if things are good. If I use another of my masks, it will be different.

As far as the AHI goes, an average of 3.6 is very good. An AHI of less that 5 is considered as apnea well treated.

Hope that helps.

The acceptable leak rate differs with each mask, and it's also dependent on your set pressure. Each mask's user manual provides a chart of some sort which explains the acceptable leak rates. In your case, Resmed provides an okay but not great amount of info about leak rates for the Swift LT. If you still have your User Manual, there's a chart on page 9 entitled "Pressure Flow Curve." If you don't have the User Manual, here's a link to an online version: http://www.resmed.com/en-us/products/se ... er-mul.pdf

The idea with the chart is to match your set pressure with what your machine says is your leak rate to see if it's acceptable or not. Your machine says your leak rate is 24 L/min, and if your pressure is 6, you'd be about exactly what the chart says is good. If your set pressure is higher than 6, you'd be better than good.

Any AHI of 5 or less is acceptable. Zero is the target, but it's rare to consistently hit zero. Your AHI is quite acceptable.

So my not-at-all-expert opinion is that your numbers are very good, and if you're getting at least 7 good hours of sleep each night, it sure sounds like you're doing very well. The bottom line is this: How are you feeling? Do you wake up bright-eyed and bushy-tailed? Are you awake and alert throughout the day? Do you have good energy? As you can see, I'm quite new here, but from what I've read here, those are the most important questions.

Marsha

Hawthorne wrote:...
As far as the AHI goes, an average of 3.6 is very good. An AHI of less that 5 is considered as apnea well treated.

..

I though it was an AI <5 (not an AHI <5)

georgepds wrote:

Hawthorne wrote:...
As far as the AHI goes, an average of 3.6 is very good. An AHI of less that 5 is considered as apnea well treated.

..

I though it was an AI <5 (not an AHI <5)

I'm interested in this also! On the Resmed my HI are always over 5, but my AI's tend to be less than 1. I'm using the adage that the Resmed over report the Hypopnea's.

While Resmed machines do report more Hs than other machines, an AHI of below 5 is still considered well treated, in my opinion.

AI is the more important number but Hs should not be ignored. People with experience with Resmed machines may comment here but I still think you want your AHI below 5 or(in the case of Resmeds) it not 5 or below, certainly not very far above 5.

The person asking the question showed a Remstar machine as the machine they use. That's the machine with which I have experience and so answered from that perspective.

Resmed users may say something different for those machines.

alexcue wrote:

georgepds wrote:I though it was an AI <5 (not an AHI <5)

I'm interested in this also! On the Resmed my HI are always over 5, but my AI's tend to be less than 1. I'm using the adage that the Resmed over report the Hypopnea's.

My bad.. it looks like it is the AHI, but, the definition of hyponea is not fixed. For example, the Medicare definition requires a decrease in O2 saturation of 4%, thus commercial cpaps cannot use this definition (because they do not include oxiometers). Moreover, commercial labs use different definitions.

---Here they use AHI (http://www.apneos.com/severity.html)
"Severity Airflow drops per hour of sleep: Mild, 5 to 15; Moderate, 15 to 30; Severe 30 or more"

---Here they quote the Medicare definitions (http://www.siumed.edu/medicine/pulmonar ... neaPPT.pdf )

"Medicare Definition
-Apnea: cessation of airflow for at least 10 sec.
- Hypopnea: abnormal respiratory event lasting for at least 10 sec with at least 30% reduction in thoracoabdominal movement or airflow, as compared with baseline, with at least 4% oxygen desaturation.

They also note in the slide " Should Hypopnea Be Included- Studies showed hypopneas are clinically important, and can be scored reproducibly. Definition of hypopnea is quite variant, a survey (1994) of 45 accredited sleep labs showed that no two labs used the same definition and measures of hypopnea"

So, hyponeas are clinically important, but the precise definition varies. The Medicare definition is fixed, but not measurable with a machine that does not include an oxiometer

Though AHI and leak rate are important, what's most important is how I feel...

I can have AHI between 2-3, but if my 'Avg time in Apnea' is high, I'm not going to feel well.

I refrain from letting AHI lead me by the nose. It's about quality sleep, how I feel and how my body is healing with the therapy.

Each of us have had SA for different lengths of time and severity. SA is like an Arsonist going about the body and lighting fires randomly.

AHI and leak rate are important, I keep an eye on them. I don't correlate my entire recovery to those measurements. How do you feel??

Take care,

SG

Your leak value is pretty good at 24 with pretty much every mask; many machines alarm for a high leak value. I am a sleep tech.

You say that a leak value of 24 is pretty good with just about any mask. 2hands4u has not mentioned his/her pressure setting so how can you say that 24 is pretty good for any mask?

As far as I know, the acceptable leak rate is based on a person's pressure setting.