66 yr old woman, tall, thin with moderate OSA that I attribute to hyper mobility of tissues
I actually am a doctor myself and it does make sense that a high enough pressure inside the chest cavity can restrict blood flow return to the right atrium. The question is how high a pressure is needed to do this? In most people it is obviously much higher than the usual CPAP pressures. In my case I am speculating that because of my weak connective tissue my vena cava partially collapses more easily, thus restricting blood return. I agree that the meds you mentioned can cause leg edema, but the only medication I am on is low dose beta blocker for sinus tachycardia. Not to mention the fact that the swelling has resolved completely and not returned since I have kept the pressure below 8. My most recent results showed 0.2 AHI, 0.1 central.
I am getting the data from the clinical menu, I’m not familiar with OSCAR but will check into it. Thanks!
I have come across other references to people developing edema after starting CPAP. I just started CPAP the beginning of April and I was loving it (Airsense 10 For Her). My pressure averages just over 6 and with that my AHI went from 45 to less than 1. I am tall and thin and have joint hyper mobility, but do not fit the definition of full blown Ehlers Danlos Syndrome. I suspect that my loose connective tissue is what gives me sleep apnea as my soft palate falls back very easily. That would also explain why such a low pressure works for me. Anyway, in midMay I woke up to find both legs quite swollen (pitting edema), something I had never experienced before. I had been having trouble with my nasal cushion fitting properly that night and when I glanced at the pressure during the night it was between 10 and 11, something I had never seen before. A curious thing about the edema is that it got better during the day. Usually you would expect leg edema to get worse during the day because of the legs being “downhill” from the heart. I struggled with mask fit again the next night and the edema continued (not sure of the pressures the 2nd night). I then got a new nasal cushion, had a good fit, pressures seemed to stay low and my leg swelling went away over the next 2 days and has not returned. I have also turned off EPR and gradually lowered my maximum allowed pressure (it is currently set to 7.) My AHI was 0.3 last night so I feel comfortable with that but will continue to monitor.
I have not been able to find any info on the web about this other than people who posted here a couple years ago with similar stories, except that their swelling started right away with CPAP. My best theory is that because I have very loose connective tissue, the increased intrathoracic pressure when the CPAP pressure went up led to decreased filling of the right atrium and therefore a backup of fluid most noticeable in the legs.
I did have a normal echocardiogram in January and have no heart disease. The swelling did not cause any breathing problems either. I would love to hear from anyone with similar experiences.