Help! changed low pressure; pressure spiked off the map!

I changed my low pressure from 8 to 8.5. Then, late in the night, after 6 hours, my pressure spiked higher than it ever has and stayed there for an hour and a half (16-17). I woke up and couldn't believe the pressure! Even when awake it continued. Then, Encore shows that it returned to normal for the last hour and a half of the night.

Did I mess up? the thing is, my pressure was fine for the first six hours of the night. what happened? This is entirely new to me. Was it somehow related to my having changed the lower pressure setting?

hegel wrote:Was it somehow related to my having changed the lower pressure setting?

No.

hegel wrote:Then, late in the night, after 6 hours, my pressure spiked higher than it ever has and stayed there for an hour and a half (16-17).

What is your normal high?

9-10, tops. Maybe 10.5 on occasion.

there was a cluster of events at the start of the spike. an OA, an Hypopnea, a flow limitation, a VS and an RE all lined up! this seems unusual too. But the pressure stays very high well beyond any flags showing on my chart--for another hour and a half. Could the pop in pressure to address this perfect storm of events have caused a leak--I kept adjusting my nasal pillow after I woke up to stop what felt like a leak, although nothing shows up leak wise on my chart--and a sort of self perpetuating spike in pressure resulted? Again, I've never had anything like this happen before. It was like my machine went bonkers.

My total AHI was...1.1.

hegel wrote:I changed my low pressure from 8 to 8.5. Then, late in the night, after 6 hours, my pressure spiked higher than it ever has and stayed there for an hour and a half (16-17). I woke up and couldn't believe the pressure! Even when awake it continued. Then, Encore shows that it returned to normal for the last hour and a half of the night.

Did I mess up? the thing is, my pressure was fine for the first six hours of the night. what happened? This is entirely new to me. Was it somehow related to my having changed the lower pressure setting?

Yep. That can happen. If you're using Sleepyhead, the answers will be in the reports. You probably had lots of flow limitations and/or snores.
And, not likely related to changing the minimum pressure.
Depending on your breathing "events", it will do what it's programmed to do........unless you limit the maximum pressures.


Den

.

Your model number doesn't display.
Can you add it to the comments field?

When I had a similar problem with my AutoBiPap, Phillips replaced the unit.
You might try setting the max pressure to 11 as a temporary measure.

hegel wrote:9-10, tops. Maybe 10.5 on occasion.

there was a cluster of events at the start of the spike. an OA, an Hypopnea, a flow limitation, a VS and an RE all lined up! this seems unusual too. But the pressure stays very high well beyond any flags showing on my chart--for another hour and a half. Could the pop in pressure to address this perfect storm of events have caused a leak--I kept adjusting my nasal pillow after I woke up to stop what felt like a leak, although nothing shows up leak wise on my chart--and a sort of self perpetuating spike in pressure resulted? Again, I've never had anything like this happen before. It was like my machine went bonkers.

My total AHI was...1.1.

How was Wednesday night?

Perhaps the high pressure time was a combination of REM sleep and maybe sleeping on your back for a period of time.

I have had nights where the pressure barely got above 12 all night long and other nights I might see 18 cm for 20 to 30 minutes or so. My OSA is much worse in REM and whenever I saw those pressure spikes it was almost always during a time frame where REM was likely to be happening...like about 90 minutes after I fall asleep which is usually when the first REM stage will happen. I used to call it my witching hour because it was so common to see a substantial pressure increase at that time.

I don't know that supine sleeping makes that big of a deal for me but it can for others.
I once did an experiment where I built a wall that I slept up against so no chance of falling onto my back and I still saw the same pressure changes so I am pretty sure mine was REM related.
But people can have it happen with either REM or supine sleeping or maybe a little of both.

Rest assured though....if the machine wanted to go up there then it had what it felt was a really good reason.
I wouldn't worry about it...I would trust the machine to do it's job and if you are sleeping well and feeling decent then don't worry. Now if you find that those pressure swings are disturbing your sleep often then maybe a little compromise is in order. Maybe limit the maximum a bit and see if it allows too many apnea events to slip past the defenses.

Thanks all for the replies. Last night was perfectly normal. The thing about the pressure spike is, I was awake for most of it, just lying there with a continuous jet of air coming in, right around 15 as I later found out--unprecedented for me. This pressure, for over an hour! But since I was awake for some of this, I was certainly not in any sort of apnea state.

I think that I'm putting this down as an anomaly. I turned the machine off and got up after a while--should have done this earlier--and then when I went back to bed, it didn't spike again. (Or it may be that I hit the ramp button--I know that I did that, but I can't remember the sequence). In any case Encore shows a break in my graph, from a pressure of 15 back to 8.5, and then everything was fine.

who knows?

Stuff happens.