[CPAP] AHI increased after doctor increases pressure 2nd time

[ppk8]

Hi All,

So I had been using cpap for 3-4 mths and my AHI was not going below 10 (please see screenshot titled "Situation 1"). My min pressure was at 4. 

So i decided to go see my sleep doctor who increased the min pressure from 4-10. This helped and reduced the AHI to 5 (please see screenshot titled "Situation 2"). But it was not going below 5 and i was still waking up feeling tired.

So my doctor then decided to increase my pressure again (from 10-12) and this severely increased my AHI to 15 (please see screenshot titled "Situation 3"). I woke up feeling horrible today

I would love if anyone could help me as my doctor is not available for a few days so I will not be able to consult her. 

I use the resmed nasal pillow. 

Thank you very much for all your help. 

PK

[DeepBreathing]

G'day ppk8. Welcome to Apnea Board.

The outstanding trend I see is that you are experiencing a lot of "clear airway" apneas, and these increase with every increase in pressure. There are two basic types of apnea: 1) Obstructive, where your airway collapses in your sleep, blocking the flow of air to your lungs; 2) Central ("clear airway"), where the brain does not send a "breathe now" message to your lungs and diaphragm.

It's important to know if you had central apneas in your initial sleep test before you went on to CPAP. Central apneas can occur naturally, or they can be induced by CPAP therapy. The therapy causes a change in the amount of CO2 in your blood stream, and this tricks your brain into thinking that it doesn't need to breathe. Quite often these induced centrals will go away over a few weeks as your body gets used to this new way of breathing. Sometimes they don't and a different type of machine is needed.

There are a number of things you can try to reduce the number of centrals, and hence your overall AHI. First two things I would try are: 1) Turn off the flex, and 2) return your minimum pressure setting to 10. Other members might suggest different settings - the thing is to adopt one set of advice and stick with it for a few nights to a week and let your body adjust. Don't be tempted to try a new setting every night.

When you see your doctor, make sure she is fully aware of all the central apneas which are getting worse with pressure increases. A lot of doctors don't seem to understand centrals and treat all apnea as obstructive - this is a big mistake.

[ppk8]

Hello,

Thank you for your reply and I will try what you mentioned.

No, indeed my sleep study suggested I only have OSA and not central sleep apnea. That's why I am shocked as to why this is occurring now?

Pk

[Walla Walla]

I think I'd drop the pressure back to 10cm and turn off the flex. You seem to do better at 10cm and turning off the flex should help lessen the CA events. It's a short term fix to try and make you feel better. Your Doctor needs to get involved to fix the CA events for the long term.

[Sleeprider]

After looking at all three graphs, I think Deepbreathing and Walla are both correct that a lower pressure is going to work better for you. With pressure from 10-20, you still had nearly 6 AHI, mostly CA events. I think your magic number is closer to 8-cm pressure and 10 is still too high. Your Flex level at X1 seems okay, but you might do better with Flex off. Try it both was. If you use auto pressure instead of fixed CPAP, then maximum pressure should not be higher than 12 cm. I actually think you'd do best at fixed CPAP at 8.0.

[ppk8]

Hi All,

I lowered my minimum pressure to 9 and turned off flex. Unfortunately my AHI was at 10. The 90% pressure was at 10.

Question:
1) Should I increase my minimum pressure to 10 or lower it to 8?
2) Should I turn flex back on?

As you see in situation 2 chart, my AHI was around 5 with pressure at 10 and flex on.

Please let me know your thoughts.

Regards,
Pk

[Sleeprider]

Pressure at 10 and Flex at 1 resulted in the best therapy you have posted. You seem to have very mixed events. Did you have a sleep study and titration study? Do you have copies of any sleep study? With complex (mixed) apnea, your results may be very inconsistent at any pressure. Your doctor is probably going to want you to keep trying, but if it doesn't settle down in 3-4 weeks, you will probably be looking at a bilevel therapy with backup rate to resolve the central events. Just so you are aware, the technology is adaptive servo ventilation (ASV), but you aren't there yet.

[ajack]

10 seems to be a good number for you.
The good news is the way the insurance works, it will take some time to jump through the hoops and you will know if you need another machine by then. If you didn't have a lot of central CA during your sleep study, you may be okay. New user, pressure induced clear airway CA settle down for most people within 12 weeks.

A lot of clear airway CA seems to be the body balancing out the co2/o2 levels and don't have an o2 desaturation, which is a real central CA. A month will give you a good idea whether they are reducing. You can also use the 'events' tag above the ahi number, this will give you the length of the clear airway CA, if they are all under 20-30 seconds, it's a good sign. Later you can put up some zoomed in sections for opinions.

[DeepBreathing]

The good news is the way the insurance works, ...

I didn't know you were an expert on the Thai insurance system, ajack.

[ppk8]

thank you for your help guys, i will switch to 10 as the minimum pressure

should i switch flex back on and keep it on level 1 (as per before) or should i switch it off? or does it even make that big a difference...