APAP vs. CPAP Quality of Sleep Difference

[tigeragent]

I began CPAP in October 10 with a CPAP prescription for 11cm. The pressure did not bother me, but I wanted to see what APAP felt like. Taking the advice of other members on the board, I set my S9 AutoSet to a range of 9cm - 13cm.

In looking at the ResScan data, I noted that the main difference between the CPAP sleep and APAP sleep was that under CPAP, I would get a handful of both obstructive and central apneas each night (although my AHI was always 2 or lower), while under APAP I am not getting obstructive apneas any more.

What is also interesting is that the highest pressure the S9 has reached is 11.2, with most nights averaging about 11, my titrated pressure.

I'm wondering why my obstructives have stopped, but my pressure has stayed the same, or even decreased. For now, I'm leaving it on APAP because I am certainly happy with those results....

[alex a]

I noticed similar findings. I moved to a PR Syteme 1 Auto from their more basic CPAP model. Using the software I was able to determin that with the settings initially prescribed I was having an AHI of around 5-7. With the auto settign I am down to an AHI of 3. My pressure ranges from the prescribed 7cm to 10. Very happy with the auto unit and also feeling better.

[avi123]

I began CPAP in October 10 with a CPAP prescription for 11cm. The pressure did not bother me, but I wanted to see what APAP felt like. Taking the advice of other members on the board, I set my S9 AutoSet to a range of 9cm - 13cm.

In looking at the ResScan data, I noted that the main difference between the CPAP sleep and APAP sleep was that under CPAP, I would get a handful of both obstructive and central apneas each night (although my AHI was always 2 or lower), while under APAP I am not getting obstructive apneas any more.

What is also interesting is that the highest pressure the S9 has reached is 11.2, with most nights averaging about 11, my titrated pressure.

I'm wondering why my obstructives have stopped, but my pressure has stayed the same, or even decreased. For now, I'm leaving it on APAP because I am certainly happy with those results....

I would try to set the APAP to 9 to 11 cm/H20 and see if it responds faster to events

[jmelby]

This is an interesting observation... I am no expert, but I wonder if simply the act of the pressure increasing is helping "open up" your airway when a flow limitation is detected. That is to say that the steady pressure would not have prevented your airway from constricting, but the act of increasing the pressure did (even though the actual pressure was no different or even less).

The respiratory tech at my sleep lab tried to switch me to CPAP mode after my 95% pressure was determined, but I too found that my AHI went way up (on a straight pressure of 11) vs. APAP 9 - 13. I also woke up each day from CPAP feeling awful, so I switched it back to APAP and have never turned it back.

[Muse-Inc]

Remember, APAPs are preventative, they respond to certain breathing irregularities (assumed to precede an event) by increasing pressure to abort the impeding event. When breathing stabilizes, the APAP drops pressure. It could be that more events are being caught by the APAP.

My constantly changing airways (chronic congestion issues) mean that I need continuously changing pressures to keep my airways open and prevent those breathing irregularities. There are a number of us who do better on an APAP than a CPAP.

[avi123]

It's interesting that past studies showed the opposite.

Excerpt:

Bi-PAP with an inspiratory
pressure of 12 cm H20 and an expiratory pressure
of6 cm H20 seems to be much less effective
in splinting the upper airway open than a
CPAP of 12 cm H20.

[jmelby]

It's interesting that past studies showed the opposite.

Excerpt:

Bi-PAP with an inspiratory
pressure of 12 cm H20 and an expiratory pressure
of6 cm H20 seems to be much less effective
in splinting the upper airway open than a
CPAP of 12 cm H20.

This is talking about Bi-PAP with a very low expiratory pressure.... not sure I see how this compares at all to APAP. APAP is not dropping pressure during expiration. It lowers the pressure slowly over time until it detects an event that causes it to rise again.