Newbie intro ....

[osborsr1]

Folks -- Hi! ....I'll be drifting through here from time to time to share what I know (not much at this point) and learn (a lot I suspect/hope) from the collective wisdom on this forum .... I'm a 58 year old male recently diagnosed with OSA ... moderate AHI (15.4) except severe in REM (can't recall, but it's very high - 60??) .... my wife has been "tolerating" my load snoring for a couple of years now .... finally got Dr's to prescribe a sleep study this past November ..... viola!! .... now I'll be joining the ranks of the night-time scuba-sleepers (sorry - the gear just reminds me of this) .... my titration study yielded a pressure of 9.1 .... so I guess I'm a middle-of-the-roader .... scanned through many of the interesting posts .... I did find a web site of a medical study on CPAP and using APAP as an alternative to CPAP titration ..... what was interesting is that a reference pressure (represents the median setting for a group of folks - there's a spread around this median) that is proportional to some constant times your AHI plus another constant times your neck circumference plus a third constant times your BMI plus a fourth constant .... plugged in my numbers and BINGO! .... my titration results matched the "Pref" almost identically (=9.4) .... if interested, I will provide this equation - if only for curiosity .... but perhaps this is old news to the veterans here .... any, "glad" to be part of this forum .... ciao ....

[kteague]

Hi. Would be interesting to see if the equation comes pretty close in most cases. Can you add a link to the medical site or give the equation? Glad you and your wife now have a chance to get more/better sleep.
Kathy

[Guest]

Hi osborsr1,

Thanks for joining the forum! The more input from CPAP users will help us all deal with this unusual type of therapy. Please keep us up to date on your experiences, especially in the beginning as it will surely help others starting out.

I am not familiar with the formula you mention and it might be an idea to just post/link it for information. My first reaction was " sounds too simple" but may well be a a decent generalization. My titration yielded a particular numerical value for pressure - I think it was 8, and if I had done what the doctor prescribed - CPAP set at 8, I am really not sure where I would be today (2 years later). He more or less booted me out and did not offer a follow up appointment because I went out and purchased an APAP. He said the algorithms with APAPs were not proven and would not be responsible for my treatment. With the help of forum members (thanks Wader!) I set a wider pressure range around my titrated prescription and lo and behold my mean pressure was 9.2, peak was 15.9, and 90 percentile was 11.

These numbers were a while back but haven't changed much and they do fluctuate in this relative range every night and throughout the night.

I guess my point is, you can have a formula that would suggest a particular pressure setting and be within a suitable range for the individual. But I feel you still need a range of pressure to accommodate varying nightly sleeping patterns, temporary health issues (colds, allergies, congestion, alcohol consumption etc, etc) as well as physical changes such as weight, anxiety and others. A set formula, just as an annual titration adjustment to a particular pressure setting is really not good enough to effectively treat the apnea condition on a day to day basis.

Yeah, I know, I am a bit long winded but it's probably due to inflated APAP pressure all this time and am just now releasing it. Aah, that felt good!

Anyway, please keep us up to date - appreciate your post.

Bob F

PS - When I did a preview, it didn't show my user name - unclebob.

[unclebob]

The above post was mine, sorry.

Bob F

[osborsr1]

OK, thanks for replies Kathy and Bob!! .... will be getting fitted with my "gear" this PM and give it run tonight .... will provide update on that experience later .... Bob - you're absolutely correct about the "pressure calculation" and the formula estimates an average pressure (there is a gaussian spread around it) .... the actual equation is --

Pref=.193x(BMI) + .077x(neck circumference in cm) + .020x(AHI) + .389

please don't hang me with this though ... I'll try to refind the actual paper that discussed using this as a starting place in setting an APAP to do the CPAP titration study and provide the url .... as I said (and Bob noted also), there's a few cm's H2O + and - to the Pref .... what is interesting is how each parameter plays into the effect ....more later ....

Scott