Switched to Bipap and AHI increased

I recently switched from CPAP to BIPAP, using an AirCurve 10 S. My pressure settings are 11 and 7, inhale and exhale respectively. My AHI has gone from 6-7 with the CPAP to 12-13 with the BIPAP. Total AI and CI have increased as well. Last night, my AHI went through the roof to almost 25. When I woke up, it felt like the pressure was very low. I put my hand to my mask to be sure the machine was on. I expected the opposite results. Can anyone help me make sense of these results?

What is the breakdown of that AHI in the 3 different event categories?
What are you using in terms of software to see your results? Off the LCD screen or software?
Why did they change you to bilevel (bipap)?

sleepykiddo wrote:I recently switched from CPAP to BIPAP, using an AirCurve 10 S. My pressure settings are 11 and 7, inhale and exhale respectively. My AHI has gone from 6-7 with the CPAP to 12-13 with the BIPAP. Total AI and CI have increased as well. Last night, my AHI went through the roof to almost 25. When I woke up, it felt like the pressure was very low. I put my hand to my mask to be sure the machine was on. I expected the opposite results. Can anyone help me make sense of these results?

What were your CPAP settings?

Last night's results: Total AHI 24.7, Total AI 21.9, and Total CI 16.7. Previous nights had similar breakdowns, although the numbers were about half of last night.
We are reading the clinical sleep report off the LCD each morning.
With CPAP, my pressure needed to be about 14-15 to keep my OSA's down but my CIs increased. Doctor suspected high pressure was making exhaling difficult and machine was mis-reporting it. Switched to BIPAP to better control exhale pressure.

sleepykiddo wrote:Last night's results: Total AHI 24.7, Total AI 21.9, and Total CI 16.7. Previous nights had similar breakdowns, although the numbers were about half of last night.
We are reading the clinical sleep report off the LCD each morning.
With CPAP, my pressure needed to be about 14-15 to keep my OSA's down but my CIs increased. Doctor suspected high pressure was making exhaling difficult and machine was mis-reporting it. Switched to BIPAP to better control exhale pressure.

You need 14-15 IPAP but you are only getting 11 with your new machine. That certainly explains why you AHI got worse.
Were you using pressure relief with your CPAP (did the pressure drop down during exhalation and by how much?)

sleepykiddo wrote:I recently switched from CPAP to BIPAP, using an AirCurve 10 S. My pressure settings are 11 and 7, inhale and exhale respectively. My AHI has gone from 6-7 with the CPAP to 12-13 with the BIPAP. Total AI and CI have increased as well. Last night, my AHI went through the roof to almost 25. When I woke up, it felt like the pressure was very low. I put my hand to my mask to be sure the machine was on. I expected the opposite results. Can anyone help me make sense of these results?

Why did you switch?

Did you have an in lab sleep study where they attempted to find a suitable pressure for you and if you did do you have a copy of that result and does it show many centrals.

The bulk of your AHI is central and if you didn't have any centrals prior to the addition of the cpap pressure it is possible that the centrals are a result of the pressure.
If that is the case then they may go away with time or you may end up needing a different type of machine again that can specifically deal with centrals and obstructives.

Also sometimes the difference between inhale and exhale (called pressure support on your machine) can also cause centrals to happen.
I know someone who has about 15 to 20 centrals when she uses 4 Pressure Support and none to speak of when she uses 3 Pressure support.

How long have you been on cpap/bipap?

When did you have your sleep studies and do you have a copy of both the diagnostic and titration reports? If not, get them.
You need to figure out if the centrals are new or you had them even before cpap.

These machines are really accurate and I doubt that the machine is misflagging OAs and calling them centrals.