AHI suddenly higher

[Outlier]

I'm thinking my mask is too tight. After waking up 3 hours in last night to use the bathroom, I looked at my machine and had an AHI of 15. I laid in bed for the next 30-45 minutes stressing and worrying about all of this, when it occurred to me that my mask was so tight that it was pushing my jaw inward, forcing it into an unnatural under bite. In my exhaustion, I surmised that perhaps this unnatural position was actually making my airway more constricted. I went back to sleep and finished the night with an AHI of 7.1, and SleepyHead revealed only 6 more obstructive apneas past the point at which I loosened my mask. Seeing as how I don't notice any leaks from the mask and that the software reveals very little leakage, the mask being too tight makes sense to me. A few more nights of sleep shall hopefully prove this to be true. Thanks everyone for your kind input.

[JDS74]

Outlier

I made the same discovery with respect to my mask. I tried to control leaks by tightening the strap snuggly and had a large increase in OSA events. Now I control leaks with a cervical collar (leaks caused by jaw drop) and having the strap quite loose. I need the strap because my machine at times can have swings in pressure of 14 cm H2O responding to central apneas and get the pressure up to 24 cm H2O. For normal users of my type mask, the strap is entirely optional.

I'm glad you found the cause of your spikes in AHI.

[Outlier]

I hope it is the cause. The point at which I tightened my mask up so much (because of some small leaks when I moved around) was about the same point at which the AHI shot up. Being the logical type, however, I realize that correlation does not necessarily equal causation, but I'm hopeful that this is the problem. I'm glad to hear from someone else who had the same problem because a Google search of "mask too tight" did not reveal much along those lines.

[JDS74]

I believe your explanation is the correct one since the user materials with my mask explicitly caution against any use of chin straps which have a tendncy to pull the jaw back.

[Outlier]

I believe your explanation is the correct one since the user materials with my mask explicitly caution against any use of chin straps which have a tendncy to pull the jaw back.

I know that one night does not a trend make, but after nearly two weeks with an AHI > 10, I slept very well last night with a newly-loosened mask and registered an AHI of 1.9.

[JDS74]

Wonderful !!!

Glad to hear it.