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BiLevel Pressures Needed for Managing Clear Airway Events - rafimf - 03-12-2017
I am 76 years old with a history of a-fib and a-flutter and have a pacemaker implant. My flutter was “cured” after two ablations. I have been in sinus rhythm for about 8 months and stopped anti-arrhythmia meds 6 months ago when starting bi-level cpac therapy. I use a RESMED AirCurve 10 S with settings of 16-10 and a Phillips Amara View mask.
My average monthly AHI’s over the past 6 months has been between 2.4 and 4.3. During this period my Obstructive index has declined from 1.17 to 0.03, while my Clear Airway (CA) events initially decreased then increased slightly (from 2.93 to 1.59 to 3.86). My Hypopneas’ have been consistently less than 0.01. From my relatively neophyte view, I would think these results are pretty good since my sleep study AHI was 15.3.
Although the number of CA events are within the normal range (<5), the vast majority of my AHI events are now Clear Airway events (initially 69% now almost 90%). Most of the CA events are clustered in the hour before awaking. I have read that patients with A-fib are likely to experience central sleep apnea, or vice versa. My cardiologist thinks that the diligent use of CPAC may prevent a recurrence of a-fib. So far that has been the case. My compliance numbers are greater than 99% with an average usage of 7 hours and 30 minutes a night.
So all seems to be going well … but I do have a question about my pressure settings. It would seem that “clear airway” events would not need the high pressures I have been using? Or are these pressures necessary to ensure that the obstructive events stay less than 1.0?
I would appreciate any insights you may have about these questions.
RE: BiLevel Pressures Needed for Managing Clear Airway Events - justMongo - 03-12-2017
I wouldn't mess with it. Your CPAP pressure is now part of your left-right hemodynamics. I wouldn't change what works.
Quote:My cardiologist thinks that the diligent use of CPAP may prevent a recurrence of a-fibI believe most, if not all, cardiologists would agree with that.
Since the CAs are clustered before waking, I would speculate it to be "wake-sleep junk" Or, you are in REM sleep.
RE: BiLevel Pressures Needed for Managing Clear Airway Events - Sleeprider - 03-12-2017
I think your CA events are related to the relatively high pressure support you are using. At 16/10 your pressure support is 6.0 cm. Obstructive apnea is mainly controlled by the EPAP pressure (10 cm), so reducing your pressure support by lowering IPAP should not have an effect on your OSA. I recommend you start by lowering IPAP to 15 cm. This should have an immediate positive effect on CA. If you have an obstructive pulmonary condition or low ventilation rate (tidal volume, minute vent), then this suggestion might be something to discuss with the doctor, but for most people in otherwise good health, a reduction in IPAP should not have an effect on your health, other than reducing the incidence of CA by avoiding the hyperventilation that reduces your blood CO2 levels and can affect respiratory drive. I think it's just a bit too much, and would have the same effect on me.
RE: BiLevel Pressures Needed for Managing Clear Airway Events - trish6hundred - 03-12-2017
Hi rafimf,
WELCOME! to the forum.!
Good luck to you as you continue your CPAP therapy.
RE: BiLevel Pressures Needed for Managing Clear Airway Events - rafimf - 03-12-2017
very much appreciate everyone's replies ... I have been on the fence about making any changes....I will wait until I take a look at March info. Next doctor's appointment is in early June so that still leaves time to do a little tweaking and seek what happens.By the way, my tidal volume and minute ventilation stats are:
Tidal volume over 177 days:
- median was 600, stable over this period
- 95% was 960, trending down from 1440 to 900
- max was 2880, trending down to 1800
Minute Ventilation over 177 days
- median 8.00 and stable
- 95% was 14.62 and stable
- Max was 30 and stable
RE: BiLevel Pressures Needed for Managing Clear Airway Events - Sleeprider - 03-12-2017
rafimf, your respiratory statistics are very strong. Cutting IPAP by to make a PS between 4 and 5 cm makes a lot of sense. It will reduce CA.