One of the last things I do before turning in for the night is check my o2 sats. Usually with the cpap mask on, the o2 readings will be 94-96 without any effort. Last night the readings were around 90-91; pulse was fine and no shortness of breath. Doing PLB, the readings would go up to 94, but then slide back down to 90. I checked all of the connections to make certain everything was working as it should; oxygen, tubing, fresh batteries in the oximeter; all was functioning correctly. And I'd taken all of my meds. First time this has happened, so worrying kicked in, resulting in a very poor night's sleep. Other than feeling unrested, o2 sats are fine this morning.
The air quality hasn't been great and my sinuses have been irrated the last few days. Could this be the cause? Thoughts?