Here's the situation-After being unable to tolerate the CPAP titration at the sleep clinic ("Just leave me alone now and let me sleep!), I was sent home with an APAP to see what I could do at home. At return visit to DR after 30 days, the 7-day average and 30 day average was in the 9-10 range so a pressure of 10 on a CPAP was recommended. From information obtained by reading this forum, I knew I wanted to continue with an APAP instead of a constant pressure. Now, two weeks later, the APAP shows my average is going up close to 11. Leakage rate is down, API score close to 2/hr.
If I had taken home the CPAP set to 10 would I have been in trouble now? What causes an increase in average pressure now? I wake up occasionally with the machine pumping out 13-14 and mask leaking noisily from higher pressure (CL2).
Pressure average change
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Pressure average change
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when the machine is continually saying you need a higher pressure it may be an indicator the machine is misreading your events. You would have to consult back to your first PSG and look for any notation of CA (central apnea) or MA (mixed apnea) events found on the report.
If those events show up (even a small number) it can mean you may be at risk of central apnea. During a manual titration the PSG tech will see those CA's and avoid them with any pressure increases. They then give you a pressure to use on your CPAP which would be a pressure that avoids those particular events.
Now you switch to an autopap, it doesn't have the EEG information the tech had so it cannot see sometimes the difference between a central hypopnea and an obstructive one (no air flow in both cases). So if the machine incorrectly identifies an event as obstructive, it will increase pressure next time it sees that pattern, but if the event is really a central event, then that pressure increase itself can cause more central events. So if you continually increase the Max. pressure and the machine continually creeps up on that pressure, that is a good indicator this could be happening.
The best way to avoid it is consult with your PSG and see if those CA's or MA's were noted on the report. IF they were, then you want to set your Max. pressure to the pressure found by the PSG titration because that will be the pressure that avoids triggering those events. If that titration study showed 10cm, then that is what you set the Max. to.
If those events show up (even a small number) it can mean you may be at risk of central apnea. During a manual titration the PSG tech will see those CA's and avoid them with any pressure increases. They then give you a pressure to use on your CPAP which would be a pressure that avoids those particular events.
Now you switch to an autopap, it doesn't have the EEG information the tech had so it cannot see sometimes the difference between a central hypopnea and an obstructive one (no air flow in both cases). So if the machine incorrectly identifies an event as obstructive, it will increase pressure next time it sees that pattern, but if the event is really a central event, then that pressure increase itself can cause more central events. So if you continually increase the Max. pressure and the machine continually creeps up on that pressure, that is a good indicator this could be happening.
The best way to avoid it is consult with your PSG and see if those CA's or MA's were noted on the report. IF they were, then you want to set your Max. pressure to the pressure found by the PSG titration because that will be the pressure that avoids triggering those events. If that titration study showed 10cm, then that is what you set the Max. to.
2 posts
• Page 1 of 1