Dealing with high pressure (New Kid on the Block)

[Frog Prince]

I had my sleep study done a little over a month ago. Halfway through the first night baseline study I guess they saw enough of my severe apnea (AHI – 78, OI -64%) and decided to start CPAP right then. After trying various nasal masks that didn’t fit or leaked they tried one with nasal pillows which seemed to work. They started at 6cm and stepped up to 18cm over a 6 hr. period. Much to my surprise I slept straight through the night even with the varying pressure settings. Normally I would be getting up every hour or hour and a half. I had assumed this problem was related to being diagnosed with BHP(benign prostate hypertrophy) which I’ve had for several years, but with CPAP I slept like a baby without having to get up at all.
I returned the following night for a follow up study. This time they found a large Comfort-Gel nasal mask that seemed to fit. The evening started out OK but long about midnight I started to weak up from a leaking mask. For what ever reason the technician kept jacking up the pressure which was blowing the mask off my face ending up at IPAP= 22 and EPAP= 17.
When I received the reports they prescribed a Philips Respironics System One BiPAP at settings of IPAP= 22 and EPAP= 17 with a full face mask. When I purchased the machine from a different sleep clinic they couldn’t get a full face mask to seal properly at the high pressures. The best we could find was a large Comfort-Gel nasal mask with a chin strap.
When I reviewed the sleep study reports I could see no reason why they set me so high. The report indicated that events were minimal at about 16/11cm. I wrote a letter to the doctor but got no response. I finally got an appointment for the first follow up visit after the study on Nov 4.
I’ve acquired a clinical manual for the Philips Respironics System One BiPAP machine as well as Encore Viewer 2.0 software. But I have not changed the prescribed settings (yet) but the first 20 days of data would indicate the pressure could be adjusted down.
At the 22/17 settings I have an average AHI of 3.6, Large Leak Rate of 6.6%, HI average 0.8, CA average 2.0, OA average 0.6, and a PB average 2.1 and this was due to just a couple of night being high, its mostly below 1.
It took me a couple of night to get use to the rushing noise of the air going through the mask even when it did seal. It’s the periodic leaks that wake me up.
The questions I have are:
Is this high pressure unusual? What would make the doctor prescribe this high pressure?
What masks work well with this high pressure?
Many of my problems have gone away since starting CPAP. No more night sweating. I have to get up maybe once a night rather than 5 to 6 times. No more trashing around in my sleep. No more snoring to the point I keep my partner awake or scare her with my stopping breathing for up to 30 seconds. No more falling asleep at my desk or getting drowsy behind the wheel.
I never realized it could have this effect and I’ve learned so much just reading the forum.
Now I just want to try and get the pressure down to a level that doesn’t wake me up from the leaking and blow-by around the mask.
Any advice would be welcomed.

[KatieW]

In your sleep study, how much of your titration was in REM Sleep? And was there a positional difference? Are you on any meds that might affect AHI? Perhaps that's why your pressures were set higher, to allow for those. Let us know what your sleep doc says.

[Janknitz]

This time they found a large Comfort-Gel nasal mask that seemed to fit. The evening started out OK but long about midnight I started to weak up from a leaking mask. For what ever reason the technician kept jacking up the pressure which was blowing the mask off my face ending up at IPAP= 22 and EPAP= 17.

I'm not positive, but it sounds to me like they kept jacking up the pressure because the mask was leaking. But that doesn't make a lot of sense as any readings would be incorrect as long as there was leaking. Maybe someone who is a tech can chime in and explain the rationale.

At any case, nasal pillow masks will work at your pressures, and it sounded like you were quite comfortable in them during your first study. From what I understand, the ResMed bipap won't work with some nasal pillows because of the settings, but the Respironics machines will. So you might want to try a Swift Mask (LT or FX) and see how it goes. There is less surface area contact with nasal pillows, and less area to spring leaks.

Are you using a ramp setting on your machine? That is often a source of leaks at higher pressures. When you put the mask on the pressure is low and that's how you fit your mask. When the pressure goes up, the setup won't hold against a higher pressure. If you are fairly comfortable with your pressure settings, you might want to discontinue the ramping. At the very least, turn it off and go to your regular pressure settings while you adjust the mask.

[Guest]

I thought an auto bipap decides what pressure you need to keep your airway open

there seems to be no reason why you can't have your pressures set from 8 to 25

start the ramp at 4...then it ramps up to 8...then the machine decides what you need

I have one and I don't think it goes above 25...but the machine is supposed to find the right pressure

my average is around 13...though the doctor thought I would need higher pressure...hence the 25

I'm new at this...only 3 weeks...I see the doc next wednesday to go over the info on my machine

evan

[jweeks]

Is this high pressure unusual? What would make the doctor prescribe this high pressure? What masks work well with this high pressure?

Hi,

High pressures are not all that unusual. Typical CPAP & APAP machines can go to 20, a BiPAP usually goes to 25, and ST and ASV machines typically go to 30. A pressure of 17/22 is pretty high. I am at 13/20 when I am on my side, but no pressure level can treat me if I am on my back.

The idea with pressure is that a variety of different pressures are tried until they find a pressure that treats your events as best as it can. The pressure acts as a "stent" to hold open your airway when you breathe. Once you hit that magic pressure level, you suddenly are able to breathe just like someone one flipped on a switch. The pressure level is independent of severity. You can have a mild case that needs high pressure, or a very severe case that needs only modest pressures. The majority of people that cycle through the forum seem to be in the 7 to 12 range.

High pressures can be tough to deal with. I have tried 8 different masks. The only one that I can deal with is the Swift LT, and even that doesn't work perfect since I have slightly slotted nares (rather than exactly round holes at the bottom of my nose). The front of my face is very rounded with a high cheek bone, so none of the nasal or full face masks work for me. I had some success with a hybrid, but I ended up having to have it so tight that it hurt my jaw over time.

Unfortunately, this is a trial and error kind of thing that can quickly get expensive. But once you find something that works, life can quickly return back to near-normal.

What I am concerned about is the mask leaks. That can invalidate the AHI numbers and it can make your machine go bonkers with the pressure. Each mask has a planned leak level. If you are much above that, or get into a situation called "large leak", then anything that the machine does or reports is suspect. If you can read your data graphs, look first at your leak line.

If you did get titrated incorrectly, then you have three options...

1) get a new sleep study, hopefully at a better sleep center such as a major cardiac care center
2) try to titrate yourself on your own
3) go with what you have given that you are having some success

Many of my problems have gone away since starting CPAP. No more night sweating. I have to get up maybe once a night rather than 5 to 6 times. No more trashing around in my sleep. No more snoring to the point I keep my partner awake or scare her with my stopping breathing for up to 30 seconds. No more falling asleep at my desk or getting drowsy behind the wheel.

I found exactly the same thing. I was getting up every 60 to 90 minutes to go to the bathroom. That can really put wear and tear on your kidneys, especially if you have high blood pressure. I haven't gotten up once to go to the bathroom since I started on the machine. My neighbors used to pound on the wall when I was snoring. They no longer do that, so I hope I am not snoring any more, or at least not at richter scale levels.

-john-

[PST]

Welcome, New Kid. Most aspects of your experience fit right in with those of others around here. Having a "split study" is normal for those who demonstrate severe apnea during the first half of the night. Your AHI at 78 is high, many people appear here with AHIs in that territory. Mine was 87, which is not to try to one-up you but just to reassure you that yours doesn't single you out. I do think that an oxygen saturation of 64 percent is unusual, so it's good you're getting treatment.

One aspect of your experience that rang a bell with me was the sudden end of nocturia. Many of the middle-aged guys getting up five times a night think it is due to BPH, and we are amazed when our constant trips to the bathroom stop suddenly the first night on CPAP, bang, just like that. There is a reaction to low oxygen saturation in which some of the arterioles to the lungs constrict in order to perfuse more lung tissue. This raises the blood pressure to the right side of the heart, and stretch receptors there generate a chemical signal to the kidneys to get moving. The whole sequence is a form of protection against congestive heart failure, with the body dumping water to lower the strain on the heart.

What does not seem familiar in your experience is the initial prescription of a BiPAP machine and the very high pressure. I think that most people here with BiPAP at high pressure got there only after the more usual treatments didn't fully do the trick. I wouldn't want to second guess anyone's doctor, but in my opinion, your situation calls for a detailed face-to-face conversation with your sleep physician ASAP in which he or she explains why your results call for this level of pressure. Most CPAP and APAP machines max out at 20, and this is enough for most cases. I know from my own experience that 17 can be frustrating for leak prevention. That's not to say that your pressure is wrong, but it falls outside of the routine, so I hope some technician's calculation is not getting perfunctory approval by the doctor. Your level of pressure is going to make adjustment harder, so you deserve a thoughtful analysis of your case and an explanation of why it is really necessary.

Congratulations, though, on how well your therapy is relieving symptoms. When you get positive feedback like that from the start it's much easier to solve the problems than when you aren't sure it's working yet.

[Frog Prince]

Thank you all for the advise and thoughts on my high pressure problems.
I'm meeting with my doctor today with about 28 days of reports in hand.We'll see what they have to say.
Thanks again for all your input. It does put my mind at ease when I know there are caring people that understand the problems.

Frog Prince (aka Walt)

[Deano]

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[Frog Prince]

At my appointment yesterday I convinced the Dr. to change my settings from BiPaP - IPAP=22 / EPAP=18 to BiFlex with a max of 20 min 14. What a difference, the IPAP never got above 18 and the AHI=0.3!!! I had the best nights sleep since I've been on CPAP.
I told them to take there sleep study analysis and put where the son doesn't shine.
Now the next step is to investigate nasal pillow masks.

Thanks again for all input.

Walt