what's an acceptable leak rate?

Six days into my CPAP treatment.

I downloaded the ResMed software yesterday and had a chance to look at the detailed data for my first 5 nights of therapy. (Thanks, Uncle_Bob for providing the link!)

I can now see why the LCD screen's "Leak" data is largely meaningless since it is just the 95% leak rate, and so far it's been well, well above the software reported "median leak rate" and pretty close to the software reported "max leak rate"

Now, I know my median leak rate has to be pretty good since on the five nights that I've looked at the data, the median leak rate was listed as 0.0. In looking at the detailed leak rate graphs, it is clear that every night I seem to have no leaks for most of the time---flat horizontal line right at 0 for most of the night, but I also have somewhere around 3--5 leaks per night that seem to be about 15--20 minutes long and peak at around 10--15 L/min, which is well below ResMed's red line that's just below the 25 L/min. Every morning the LCD shows the Green Smiley face in the short version of the Sleep Quality Information.

Are these leaks significant, or are they minor enough for me not to worry about?

Good question. On the Activa the leak is zero. On Swift II nasal pillows, the leak is 5. If one's AHI is under 1.0 with either, is the leak rate of no significance ?

Read your manual for your mask. There should be included information that gives you the acceptable leak rate at a given pressure setting.

I think the leaks are significant if the noise or air is waking you (or sleeping partner), or the air is leaking into your eyes (and causing dry eyes). Or if they are caused by mouth breathing.

When you look at your data, narrow the lower Detailed Graph to 10 minutes, and see if there are any events during the leak period. Or, if your pressure is going up during the leak period. That will tell you that the leaks are affecting your therapy.

KatieW,

Thanks for the tips. So far the leaks have not seemed to bother my hubby at all. And except for the first night, I haven't had any problems with leaks blowing into my eyes. I've woken up a time or two and adjusted my mask most nights, but it's not been a battle. The most significant bothersome leaks occured on nights 3 and 5 *before* even got as far as lying down in the bed. Got so mad on night 3 that I even threw the mask at the CPAP machine and it took a long time for my husband to settle me down enough to try putting it on again. A similar thing happened at the beginning of night 5

I did indeed quickly look at the Detailed Graphs on 30 minute windows looking for correspondences between events and leaks. Seemed almost random. Sometimes yes, sometimes no. This weekend I'll look at the data much more carefully though.

Physician wrote:If one's AHI is under 1.0 with either, is the leak rate of no significance ?

Hi,

If there are leaks, the event data and the AHI numbers might not be valid. Leaks have to be within the normal level of any given mask before you can count on the AHI numbers being accurate.

-john-

taberge wrote:Read your manual for your mask. There should be included information that gives you the acceptable leak rate at a given pressure setting.

That's true if a person is using a Respironics machine like the Respironics M series machine your equipment profile shows, taberge.

But for those using a ResMed machine (as robysue is) ResMed accounts for the expected acceptable leak rate (from the mask vent) when the person chooses the correct "mask setting" on the machine for the mask they are using. Ideal leak rate for a ResMed machine (since the acceptable leak rate is already subtracted) is 0.0.

Ideal leak rate for those using a Respironics machine is the acceptable leak rate for the mask and pressure they're using. Won't be (and shouldn't be) zero for a Respironics machine user.

rested gal wrote:

taberge wrote:Read your manual for your mask. There should be included information that gives you the acceptable leak rate at a given pressure setting.

That's true if a person is using a Respironics machine like the Respironics M series machine your equipment profile shows, taberge.

But for those using a ResMed machine (as robysue is) ResMed accounts for the expected acceptable leak rate (from the mask vent) when the person chooses the correct "mask setting" on the machine for the mask they are using. Ideal leak rate for a ResMed machine (since the acceptable leak rate is already subtracted) is 0.0.

Ideal leak rate for those using a Respironics machine is the acceptable leak rate for the mask and pressure they're using. Won't be (and shouldn't be) zero for a Respironics machine user.

Same for an IntelliPAP AutoAdjust user, as 'discussed' at this topic -- viewtopic/p524284/ResScan-vs-SmartLink- ... ml#p524276

Ok, back to topic: I"m using a Resmed S9---not a Resprionics or Intelipap so the link in DHC's post is not useful to me. The S9's owner's manual and clinic manual say darn little about how to interpret the leak data.

For what it's worth:

My mask is a Resmed Swift FX and the mask setting on the S9 is set correctly to "pillows".

My hose is the Slimline that comes with it and the hose setting on the S9 is correctly set to Slim. [This is not the same as the heated Climate Control hose that's listed under "humidifier" in my sig. There seems to be NO option to pick the Hi5 without the Climate Control hose by the way].

Except for a very few, very short leaks caused by me partially taking the pillows off for a minute or two, ALL my detailed leak data stays below the red line the ResScan software draws at 0.4 L/sec = 24 L/min. What I can gather from the owner's manual and the clinical guide is that if your 70% leak rate is above this line, that's when you get the Red Frowny Face on the LCD under the sleep quality information menu. Most of my data falls well below that line. Except for my very first night, the ResScan software indicates my median leak rate as 0.0 L/m every night. That means that my leak rate is at 0.0 for at least half of every night. My 95% leak rates have stayed below 15.6 L/min, and most of the time are much lower. So at these rates is it reasonable to trust that the event data is correct?

I've now had a much closer look at the data: The events that go into my AHI are almost always during times where the leak is 0.0 L/min: Out of the 37 events recorded in the seven nights I've used the machine, 31 of them have occured with a leak rate = 0.0. Of the six events that occured with a leak rate > 0.0, the leak rates range from 1.2 to 19.2 L/min. At this range, should I be able to trust the apnea and hypopnea data?

And in looking at the leak data itself, what seems to happen most of the time is that a slow, but steadily increasing leak starts. Somewhere between 10 and 20 minutes after the leak starts, there's a very sudden drop in leak rate to 0.0---the drop to 0.0 occurs over a 10--30 second time frame. Seems to me like I'm most likely waking up very briefly to fix the leak and then pretty much immediately falling back to sleep. This happens maybe 4 or 5 times a night.

So I know that my leak rates are not perfect. But are my leak rates decent enough for a beginner to not get overly worried about?

robysue wrote:Ok, back to topic: I"m using a Resmed S9---not a Resprionics or Intelipap so the link in DHC's post is not useful to me. The S9's owner's manual and clinic manual say darn little about how to interpret the leak data.

Sorry about that. Since that other topic was addressing the ResMed S9's apparently unique algorithm for calculating leaks versus others, I thought it might be helpful.

Apologies for the disruption.

robysue wrote: So I know that my leak rates are not perfect. But are my leak rates decent enough for a beginner to not get overly worried about?

I don't know what the magic number is. But I think it's something you should continue to work on, because waking up 4-5 times to adjust your mask does disturb your sleep. Finding a mask that fits well, is comfortable, and doesn't leak is a challenge for most of us. I would suggest also looking at your hose management and head pillow, as they might be dislodging your mask. It takes time to work all this stuff out. For a beginner, you're doing fine.

Most masks expiratory port leak rates are between 30-40 LPM. You can indeed find this rate in the masks user manual.

KatieW wrote:

Finding a mask that fits well, is comfortable, and doesn't leak is a challenge for most of us. I would suggest also looking at your hose management and head pillow, as they might be dislodging your mask. It takes time to work all this stuff out.

I'm working hard on dealing with the hose management issue and pillow issue since I think they're my number one issue right now because they're at the root of the insomnia I'm having right at bedtime. It's going to take some time and work to get those issue really resolved nicely. And that's why I'm hoping that my current leak rates are "ok" enough where I can put them on the back burner.

Yes, the leaks are apparently waking me up, but I don't remember the wake ups at all and I do remember the long struggle to get comfortable enough to fall asleep at night. So if I can safely ignore these leak problems for the time being, I"d like to. That will let me focus on solving my main problem, which as you picked up on is hose, pillow, and cover management, not mask comfort. [The FX doesn't bother me that much unless it gets caught in my hair and pulls, which happens when I"m trying to get the mask on and sealed at bedtime.]

You may well find that your periodic leaks are being caused by tension on the hose, and that a good hose management plan will help that issue, too.

DHC wrote:

robysue wrote:Ok, back to topic: I"m using a Resmed S9---not a Resprionics or Intelipap so the link in DHC's post is not useful to me. The S9's owner's manual and clinic manual say darn little about how to interpret the leak data.

Sorry about that. Since that other topic was addressing the ResMed S9's apparently unique algorithm for calculating leaks versus others, I thought it might be helpful.

Apologies for the disruption.

You didn't disrupt anything at all, DHC. In fact, the link you posted went to a very helpful discussion. Thanks!