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questions for the PD patients-lost dwell time and neg. UF

PostPosted: Fri Oct 23, 2009 11:33 pm
by Pam
Hi guys,
I have been doing APD since July 16, 2009 and it is going great, but I am confused about "lost dwell" time-I have it almost every time I dialyze. What is it and how does it affect one's dialysis treatment? Also, I get a negative UF occasionally and want to know what that means in terms of treatment quality?
Thanks very much!

PostPosted: Sat Oct 24, 2009 8:39 pm
by MandyV
Hi Pam - 'lost dwell' and negative UF are indicators of less that optimum APD.

The dwell time is the time the fluid is in your peritoneum which means that less time there means less time the toxins can be transported into the PD fluid by osmosis and therefore you may not get the clearance which is optimal. I wouldn't worry about small numbers but if you have a bad night then it is worth discussing with your PD nurse. For example for me it was often a sign of fibrin which needed to work its way out.

Negative UF means that instead of taking fluid off you have gained fluid so again not ideal but usually from your day time dwell if it has been in too long. Again if I had this it was usually in conjunction with 'lost dwell' and also generally due to fibrin. If this is not followed by a better night you might become a bit fluid overloaded and uncomfortable. Again worth discussing with your PD nurse.

PostPosted: Sun Oct 25, 2009 11:12 am
by kiskeam
Hi Pam,
When I first went on the machine I had same problems, but the nurses switched me to Tidal, which means during the drain only a percentage is taken out and during the final drain everything left is removed. This works much better from me, and providing that I am sat up during my last drain I get a great UF.
It also helps with any pain you might get when the machine is draining. It stopped all that.
Also I don't worry if I get a poor UF, I allow for it during the day and reduce my fluid intake but usually on the next initial drain it all comes out.


PostPosted: Mon Oct 26, 2009 7:39 pm
by MandyV
Good point from Claire - actually I was on a tidal setting because I found that each cycle took so long to drain (I was always a slow 'drainer') that it would alarm etc so it is well worth while asking about it.

Re: questions for the PD patients-lost dwell time and neg. U

PostPosted: Fri Aug 04, 2017 4:40 am
by Epgibbons
hi, the baxter machine has a feature called smart dwell which is on by default. it is to ensure the whole therapy ends when requested. if a drain takes longer than expected the dwell time for following cycles is reduced -leading to lost dwell, and reduced dialysis. I have this feature turned off. it does mean that the therapy will take longer.
negative uf indicates poor final drainage . I can get the same. so I program a final manual drain if it is low. During the manual drain I wiggle around standing and sitting. in some cases I stop the drain and fit a drain bag which allows me to disconnect from the machine and start my day; reconnecting after about an hour for the last fill