That's probably so about a good many limited flows, which is what an hypopnea is. However, I think it's important to eliminate hypopneas that cause arousals without any significant desats involved. Arousals can wreck sleep architecture. Enough of them and a person could wake up in the morning not feeling rested at all, even if they didn't have much/any dip below 90% in their O2 sats all night.NightHawkeye wrote:Many/most cases of reduced breathing are simply normal events without any adverse effects.
One of several definitions of an hypopnea is:
from sleepydave:
"The definition of a hypopnea varies a bit, but generally, it's a 50-80% reduction in breathing, with a desaturation and/or an arousal." (bold emphasis, mine)
http://www.apneasupport.org/viewtopic.php?p=2827
So, hypopneas can interrupt smooth sleep by causing just an arousal, without a dip in oxygen saturation.
Explaining "arousal", sleepydave writes:
"An arousal is simply a 3 to 15 second break in sleep continuity, and an awakening is 15 seconds or more. It's usually to an alpha pattern. You may be aware of awakenings (not to be confused with really being "awake") but you won't be aware of arousals.
A hypopnea needs either an arousal and/or a desaturation to be scored as such. In adults, virtually all respiratory events will be terminated by an arousal (the rule kind forces that issue)."(bold emphasis, mine)
http://www.apneasupport.org/viewtopic.php?p=27820
Your doctor is right to be looking for significant desats, Paul B, as lack of sufficient oxygen during sleep can be very damaging to every cell in the body. Gotta keep that heart and brain in particular well oxygenated!
