Can someone help me out concerning the uf rate and the amount of saline returned during a treatment? Recently we were told to increase the target loss to whatever it takes in order to increase the uf rate to 0.40 -- the pt are upset because they try so hard to keep their weight down and now we are giving them as much as 1000 ml ns spaced out during the treatment time.
The machine we use is the Cobe 3 plus and we are using the high efficient dialyzer. In the old days we did raise the uf rate with a plate dialyzer to prevent back flow??? anyone suggestions?????
thanks, sadie rn

Sadie,
I am not familiar with the Cobe C3 or the C3 plus. I must solicitate help from the clinicians who visit this web site. I do know that in order to prevent back-filtration(dialysate mixing with blood)a minimun uf must be maintained. If patients gain very litte weight between treatments, it is often necessary to give replacement fluid to prevent them from having interdialytic morbid events. Any other information anyone may have,please jump in.
Thanks,
Nancy

Sadie,
The Cobe C-3 and C-3 plus machines ultrfiltration system are set at the factory so that the lowest ultrafiltration rate you can have is 0.40kg/hr. So, if you come in with only a .5kg weight gain and you run 3 hours when factoring in the saline rinseback of 300cc (.3kg) your total weight loss should be .8kg. Over that 3 hour time the least amount of fluid the machine will take off is 1.2kg, .4kg more than you need taken off. That .4kg is added back by giving you 400cc (.4kg) of saline (.8+.4=1.2) over the course of your treatment. I hope this example helps

If I was on Dialysis I would want large amounts of saline added to help with middle molecule clearances. The reason we don't want high weight gains is the stress it puts on the patients cardiovascular sytem not how hard it is to remove. But that doesn't answer your question, the answer to that is hard because there are so many opinions. Changing from unit to unit. The recommended from the manufacturers is usually .3 for a high flux and .1 for middle to low. This is found in the box the dialyzers come in. Truely though there is a fluid exchange at almost any UF rate, we increase sodium it goes across the membrane it is hard to believe that no fluid is exchanged with this. There is a difference however in Backfiltration and Reversefiltration, but that's anothe rtopic.