[Diagnosis] New sleep study after surgery?

[Phasenoise]

I used a CPAP machine for a year prior to FESS surgery, untreated AHI was 24/h.  Treated using the Airsense for her, it fell to the 0.6/h range pressure in a range of 8-12 cmH2O. 9 cmH2O was the most common pressure.

I had surgery in early August, to remove a grade 2 nasal polyp, correct a deviated septum, and also a turbinate reduction. 

I saw no real change in the treated AHI number after surgery, it was still in the 0.6/h range.

For the past two nights, just as an experiment, I disabled the adaptive algorithm in the Autosense.  I set the pressure to 4.0 cmH2O, which is the lowest setting.

The attached screenshot shows that the obstructive index at the reduced fixed pressure is 0.39/h, being 3 events in 7.6 hours.

Is there any chance I don't need the CPAP machine anymore?  Should I get myself re-tested?

[harrywr2]

Your flow limits(0.28) seem pretty high to me.

[Phasenoise]

Flow limit graph attached in case it's helpful.     
Overview.    

I use a nasal mask and there was some evidence of mouth breathing (saliva on pillow).

[Osiris357]

In my opinion you still need CPAP or APAP in your case. Those flow limitations disturbed your sleep a little more than 1 time an hour. That’s the equivalent of someone shaking you to wake up once an hour. Annoying to say the least right? If you were to sleep without the machine that number would likely skyrocket. I know for me when I take my mask off and put my head back down and end up falling asleep without it I wake up with this feeling of oxygen deprivation annoyed with myself for laying down without the mask on.

My AHI is regularly below 1 since I started wearing a soft cervical collar. Without the mask and collar I may think I slept but I stay in light sleep the entire time with spikes to awake according to my sleep tracking app. With the mask and collar I’ve gotten up to 5 hours of deep sleep in 9 hours and feel great when my eyes open.

The soft cervical collar prevents your chin from going to your chest folding over your airway. Without it my pressure spikes without any apneas actually occurring because of flow limitations

[Gideon]

You should always include a set of the daily charts when you as for advice.  That will be done by selecting the "Standard" charts, then hitting F12 for the screen print.  key word there is will.  

Using the autoset at a pressure of 4, and this is important.  

How do you feel at 4?
How do you feel with it in Auto?  
Is one better than the other?

You should not stop CPAP without a diagnostic sleep study that says that you do not have Sleep Apnea.

Try a night or 2 without the device.

How do you feel?
Which is better, with or without the CPAP?

If, and only if it feels better without the CPAP, get a diagnostic sleep study.  Otherwise, it is not, IMHO, worth the expense since you have already determined that with a CPAP is better.

If you continue to use your machine, I would want to manage your RERAs and likely reduce your flow limitations.

[Phasenoise]

You should always include a set of the daily charts when you as for advice.

Attached.    

How do you feel at 4?

After two nights at fixed pressure of 4 cmH2O, as well as when I am 8-12 auto.

How do you feel with it in Auto?  
Is one better than the other?

I will try that.

If, and only if it feels better without the CPAP, get a diagnostic sleep study.  Otherwise, it is not, IMHO, worth the expense since you have already determined that with a CPAP is better.

Could you post a picture of what a medical bill looks like?  I've never seen one. 

[Gideon]

Very funny,
I hope you are not mocking my right to a dual citizenship.
If it doesn't cost you dollars, it costs you time, discomfort, and effort.

[Phasenoise]

Nah, the sleep techs were scorching babes last time.  I would crawl over broken glass to see them again.

I am going to order a soft cervical collar, should not be expensive.  I tuck my chin into my chest, it feels comfortable to me, maybe that's causing the restriction.  My BMI is pretty normal, I go to the gym 3 times a week for 1.5 hours per session.

[Osiris357]

I find tucking my chin to be comfortable also. The collar may take some time getting used to and you may find yourself waking up because of it, but stick it out because the difference in the flow limitation chart along with the pressure not varying more than 1 cmH2O was motivation enough for me to keep going with it. Not to mention feeling great in the morning and throughout the rest of the day because my flow limitations were next to nothing. 

Good luck to you.

[Geer1]

I don't think you can get an accurate interpretation as to whether or not you need CPAP by lowering pressure to 4 cm.

As bonjour said try a few nights with and without APAP and see if you notice any difference.

I think I would almost trust a recording oximeter more than I would doing a single night 3rd party home sleep study again. At least you can see the data and track it for multiple days. Not a perfect test but if you are feeling fine and oxygen levels are staying in a normal range and you aren't having obvious desaturations then I think it would be safe to assume you are ok without PAP treatment.