Cpap improves AHI but not sp02

[help007]

Hello, new friends, I'm about 4 weeks into cpap therapy: resmed airsense 10, p10 nasal pillows, diagnosed with at home test AHI of 5.4 and low blood oxygen level of 85%. My original rx was a pressure of 5-10, but I couldn't breath well, now at 7-13. I now tolerate the cpap pretty well- I only take it off in the night about once a week, and I have the fit of the mask worked out pretty well.

I got a contec logging oximeter, and I wear it to bed about once a week. My cpap treated AHI averages about 2, but I'm still very tired most of the day. My overnight oxygen levels are still spiking down into the low 80s every time I log my oxygen overnight. 

I've attached my sleepyhead log for last night. If anyone has any suggestions, I'd love to hear them.

[Walla Walla]

I would try reducing the EPR to 1cm and see if that helps clear up the CA events your getting. The O2 level overall isn't bad and I suspect that if you can get rid of the CA events you won't have any more O2 dips.

[sheepless]

I agree your O2 drops are largely related to the central events. did you have clear airway or central apnea events during your home test? how many obstructive apnea did you have in comparison? there's a loose association between pressure above 7 and the ca's in your chart. pressure won't fix and probably worsens ca. can't tell at this scale if higher pressure stopped any obstructive events but there are only 1 oa and 1 h in that chart so you can try reducing max pressure; even try fixed 7 if you can breathe easy at 7. usually when it's hard to breathe we raise min but not necessarily max and it doesn't look like the higher pressures are necessary.

[Sleeprider]

I'm going to give you some homework about using your CPAP to affect SpO2. Oxygenation when using non-invasive venitlation is correlated to PEEP (Positive End Expiratory Pressure). Look it up. You are using a pressure of 7 to 13 with EPR 2, so your end expiratory pressure is pretty low. In addition, the EPR may encourage the few central events you have.

To be clear, from a therapy point of view, you are getting good results, and the 2-CA events per hour are not a problem, but if you want to increase SpO2 you need to increase EPAP. That can be done by increasing minimum pressure, removing EPR or even moving to fixed pressure that produces a higher expiratory pressure. Your obstructive sleep apnea appears to respond well to fairly low pressure to keep your airway patent, but if you want to use CPAP to increase oxygenation, a higher pressure, and especially end expiratory pressure can do that.

[help007]

Thank you for the responses. It sounds like all of you agree that low to no pressure relief would be helpful. I will give that a try tonight.

The extra insight is incredibly helpful- the tech sees that I'm under 5 AHI and meeting insurance requirements, so she wasn't interested in helping tweak things. However, while I deal pretty well with the cpap, if I'm still going to be tired all the time it would be hard to bother keeping up with it.

I need to dig up my initial report to see how things compare- at the time I received it, i didn't understand most of the terminology.

[Sleeprider]

If you ever need help with any reports or other information, we can help to interpret. There are at least a half dozen people on the forum that can help translate what I post.