Dialysis affecting CPAP data

[pholynyk]

I've been doing home peritoneal dialysis for about six months now, and I noticed an increase in my AHI over that time. This afternoon I realised I could look at one whole year using my OSCAR Statistics page:
   
I started my training late in October and started doing dialysis at home at the end of the first week of November, so we have six months before dialysis and six months doing dialysis. As you can see, my OA hardly changed and my CA increased quite a bit.

My question is "Has anybody else noticed any differences while doing dialysis?"

[Crimson Nape]

[Gideon]

.I know dialysis kicks your *** so I'm not surprised.

I'd like to see 10inn flow rate examples from pre dialysis and currently, I'd also expect to see a difference between the night before and the night after dialysis.

[pholynyk]

Ah, the home peritoneal dialysis is done every day, Gideon; in my case 3 times a day, others use a machine to do it overnight, every night. So there's no day before or day after.

>>>I'd like to see 10inn flow rate examples

I'm not sure what you like to see here. As far as I can tell, I just have a few more CA than before dialysis, Anyway, let me know

[Gideon]

Just looking to see if the character of the centrals sho in the flow rate.
Admittedly I am unfamiliar with home peritoneal dialysis. I do remember what my mother went through. She died sitting in the chair at the dialysis center 'resting' to go home.

[pholynyk]

I'm sorry to hear about your mother, Gideon. That was probably Hemodialysis, where they take blood out and filter it then put it back in, in  a continuous process. Done three times a week, the variation in toxin levels is not as helpful as daily dialysis.

Here are two sample CA from randomly chosen days before dialysis:
          

And here are two/one from after:
      

I'm going to bounce this off the dialysis doctor, and see if she knows any sleep doctors.

[Gideon]

IMHO the one after matches the second, 4 Sep, and appears to be CO2-driven breathing.
the first looks more like an arousal ending in CO2 breathing preceding the apnea.

With this sample I don't see enough difference to chase it down.

[Geer1]

Dialysis or because you changed your pressures? See how your min pressure increased from 9.6 cm min up to 11 cm min? That is probably more likely to be your issue then dialysis.

The first night with lowest AHI your pressure stayed the lowest averaging 9.8 cm, the next night AHI was middle of the pack and average pressure was 10.6 cm, worst night average pressure was 12 cm. This makes me think you get more central apneas as pressure is increased.

My recommendation would be to reduce pressure. I would start by reducing min pressure to 8 cm. Then post a few full nights of data so we can interpret the graphs. Limiting the pressure (using fixed pressure/CPAP mode) might be helpful if increasing pressures aren't helping and are causing centrals. Decreasing EPR to 2 cm might help as well but I would start with lower pressures first.

[pholynyk]

I *think* the pressure change is a red herring. If we look at more of the Statistics page, we can see that the increase in CA preceded the increased pressure, and coincided with the introduction of dialysis and particularly the change from dextrose solution overnight to icodextrin solution overnight. I started dialysis on 6 November and switched to icodextrin on 6 December.

   

The change to 11.0 cmH2O was quite recent, the CA index jumped in December. I have noticed the increase in average and max pressure, which was unexpected, and I am considering backing off to 10.0 or 10.2. I haven't used a minimum of 8.0 for many years, and my CA index has been in the small tenths with a min of 9.6. Most of my AHI has been in Hypopneas, so decreasing EPR is not an option.

[Geer1]

Most of my AHI has been in Hypopneas, so decreasing EPR is not an option.

Based on your cyclic breathing nature I wouldn't be surprised if a number of those hypopneas are central in nature. You should be able to tell by looking at detailed flow rates. If occurring during ebb of a cyclical pattern then is central in nature, if occurring out of the blue during normal breathing obstructive. My grandfather gets something similar and the machine even wrongly labels a number of his central apneas as obstructive apneas which then blows up his pressure making it all worse... Decreasing and limiting pressure helped him significantly.

On that topic I see you have tried lower pressures but something was still driving pressure up and your average pressure has been increasing nearly continuously since starting dialysis. If I look back at last June you had your next highest average pressure and highest AHI pre dialysis. Its not much of a trend (in reality your numbers aren't fluctuating that bad) but there does seem like there may be a trend of increased AHI with increased pressure. The obvious chicken or egg argument is what came first the increased pressure or the increased hypopneas/centrals? If it were me I would try a fixed pressure of 8 cm (with 3 epr) and see what your data does as that would give an indication of what is causing what.