I recently did a sleep study which revealed I have moderate OSA, with an ahi of 19. All obstructive apnea occurred within rem sleep. The thing I don't understand is that my lowest sa02 for the night was 93% and the average was 95.7%. The Sa02 literally never dipped below 90 despite several OAs? Does this even make sense? Or does it indicate a problem with the test results?
Hi Williminal
This is a subject I know very little about (amongst many) but I do know that the hospitals want your O2 to be at least 95 so there is some impact if that is what you were looking for.
19 is moderately survivable so perhaps it takes higher numbers to impact significantly on O2 levels.
Having said that it is not a number to be ignored either because if you can't make some major changes it will almost certainly get worse.
It means your oxygen saturation probably started at something like 97% and, when you had an obstructive event, it dropped by only a few percent to no lower than 93%. This means that your events only cause a small drop in oxygen. This is not unusual. Unfortunately this does not mean that they don't do you damage because they still place your heart an other organs under stress, so it is still worth getting treated. And, as Biguglygremlin mentioned above, it will only get worse over time. In order to be counted as an obstructive apnoea or hypopnoea, each event has to cause either a drop in oxygen saturation of at least 3%, or a change in your brain activity. So you can have severe OSA, which is causing your body a lot of damage, but your oxygen level may never drop below 90%. I hope that helps.
Thanks for the feedback, I guess I had read that most hemodynamic and metabolic risks occurred with saturation dipping under 90. Interesting to hear that any dip poses a risk.
You've got to stop throwing big words around Williminal!
It's getting late in my world and I'm struggling. :(
You're situation is interesting because in my mind it is on the edge of the drop-off point. If you could bring it back a few points you would be relatively safe but if it progresses the numbers will get worse along with the risks.
The odd thing is that the ent doctor said oxygenation was too high to recommend cpap and jaw is too far forward for a mad, so sort of low on options. Going hard on a throat and tongue exercise regimen currently
Oxygen too high to recommend CPAP? That's just bizarre. Is that the ENT's perspective or is it an official rule that they must abide by? If they're worth the money they're being paid, they should know that just because your oxygen saturation doesn't drop below 90% doesn't mean that you can't have severe OSA that will threaten your health (an eventually your life).
I don't believe the ENT is correct in saying a CPAP would not be appropriate. An apnea event not only causes oxygen desaturation, it also initiates arousals and awakenings which disturb your sleep. Unless your AHI is mainly central apnea events, a CPAP is likely to make a very significant reduction in that AHI of 19 to less than 5 and without centrals to about 1.