PD cycle effect on Covid patients

My 89 year old father is a PD patient. He contracted covid recently. His pulse ox has been good using a steroid inhaler and he also got an antiviral infusion two days ago. However, we noticed that he only struggles to breathe at night when he’s on dialysis. We think this is tied to his fill and dwell time, when his peritineum is full. He sleeps sitting up, so that’s not a factor. His lungs are clear as well.

Could this link be valid? If so, we’ll begin dialysis much earlier. I appreciate any help you can give.

This is a very interesting question.
I’m going to preface all of my thoughts with the general advice that nothing online can take the place of his actual medical providers having hands and eyes on the situation. Trust your intuition, and if something feels off about your dad’s condition, seek care immediately. Especially because this is a breathing issue!
It does makes sense to me that anyone with reduced lung capacity could be uncomfortable on PD. Some patients with healthy lungs have difficulty adjusting to being full when they first start. Patients with COPD sometimes have a hard time with exchanges because the decreased space and increased pressure inside of the body makes it even harder to get a good breath. This sounds like it could be similar.
I’m glad to hear you’re monitoring him at home and that he has been seen recently. Hopefully he turns the corner soon and starts to improve. With age and everything else he has going on, and the unpredictability of Covid, it’s good you’re staying astute.
I think it’s valid though, it makes sense that a person with an acute respiratory illness would struggle with fill volume from PD. If it is only happening at night while on treatment, it makes even more sense. You can try doing treatment earlier to see if that helps, not sure if it will if he can’t reposition much around it. He’s already upright.
Does he only dialyze overnight? He’s fine during the day when dry? I wonder if reducing the fill volume would help. Or, if daytime manual exchanges may work better for him right now so he can get more restful sleep. It’s going to be dependent on his individual body.
I would want to rule out anything funky going on due to Covid before feeling confident in trouble-shooting through a dialysis issue though. Struggling to breathe is awful, and I would want to know for sure that it’s not too much stress on his heart. It would defeat the purpose of doing the treatment if the treatment is causing him to be unable to breathe.
See if his team has any good ideas. I’d definitely ask about CAPD and fill volume reduction if you’re pretty sure this is his injured lungs being unhappy with dwelling fluid. He can always revert back to the previous orders once he’s recovered. Best of luck.