Different CA scores for nasal vs full mask

Hi,

I was originally given a full mask by one doctor on the grounds that I have a deviated septum that means the right side of my nose gets blocked easily. However, another doctor told me I should try the nasal type first.

I have only tried to use the full mask for one night but it started leaking and I woke at 3am with the ResMed AirSense 10 at level 12. I took the mask off and went back to sleep..

For that night, I had a CA score of 4.12/hour (the CA events coincided with high leak rates when I was semi-awake) and obstructive apnea of 3.12/hour.

Today, I tried two nasal masks for 20-mins or so each while lying on my bed during the day. I was semi-awake and stressed and nervous with various things going through my mind. I had 4 CA events in 15 mins and the CA score was 14.98. Afterwards (now), I feel bad, as though I have swallowed too much air. I managed to keep my mouth shut but I feel as though the machine is getting my breathing out of sync.

I should add the following:

My home apnea test which involved, an oximeter on my finger, bands on my waist and chest, and tubes in my nose, gave me a CA score of 2.0/hour, OA score of 12.2/hour, and hypopneas of 5.2/hour.

My PSG test in hospital was a complete disaster because I had a headache all night from resting my head with metal sensors on it against a tiny pillow full of plastic beads (no alternative pillows were available, and no painkiller was offered). I was semi-awake all night in moderate pain. The doctor confirmed I had only slept for 2-3 hours. I was told I had few apneas, but many hypopneas and 5.8 CA events per hour. I doubt this test was reliable because I just remember being half-conscious the entire night. It was probably the worst night of sleep I have had in my entire life.

Why the sudden jump in CA events during my admittedly brief tests of nasal masks?

Is the sharp increase in CA events due to my anxiety, or my deviated septum making it hard to breathe?

I swallowed a few times, coughed, probably hyperventilated, or did something unnatural with my breathing, and I think I stopped breathing while getting up to turn the machine off.

I also forgot to turn off pressure relief which I think I am better off without. I suspect the machine is too slow to adjust to my changes in breathing patterns when in EPR mode.

Any ideas?

Are you using OSCAR to track your sleep data? If not it would be worthwhile to see in more detail what is happening. The software is free, but you need a Mac or PC and a SD card reader to use it. It provides a lot of detail which you can help to determine if your CA events are real or not.

In general when one is sleeping poorly and waking up you can get false flags of events. It is best to evaluate your results on a full night of good sleep.

There is no reason for a nasal mask to cause more events than a full face. You do have to change the setting in your setup to match the type of mask you are using though. Since your CA score was not that high during your home sleep test, and seems to be higher now, it is likely you are suffering from treatment emergent central apnea. The higher the pressure the more likely CA events are to occur. In most cases this effect goes away after 6-8 weeks of CPAP use. But, in general it is best to minimize the treatment pressure to what works for you. If one mask or another results in more pressure for some reason then the frequency of CA events can also change. OSCAR lets you see when and at what pressure events occur, so you can determine possible causes.

For a long time I had EPR set to run only during the ramp period and turn off after the ramp. But when I did a more extended test with EPR set to 2cm and full time, I got a reduction in hypopnea, and overall AHI reduced from about 2 to less than 1. But everyone is different. The best is to try it on and off for an extended period of time to see what works. In some, having the EPR on can result in more frequent OA events, and that in turn would cause the machine to use more pressure.