What is the difference between ultrafiltration and sequential filtration?

Specialties Urology Nursing Q/A

I am new graduate and I am studying to take the BONENT exam. I am confused about the difference between sequential and ultrafiltration? I understand that sequential means to remove excess salt and fluid. Isn't that what ultrafiltration is doing as well? I also understand that UF/SEQ are to pull fluid only,there is no blood being cleansed. Is this correct?

6 Answers

Specializes in teaching, research, and evidence-based practice.

Both are used to remove excess fluid from the blood, but they work in slightly different ways. 

Ultrafiltration only removes excess fluid from the blood – not waste products. The process involves the use of a pressure gradient across a semipermeable membrane to pull fluid from the blood.

With sequential ultrafiltration, excess fluid and salt are removed from the blood in two stages. In the first stage, a hypertonic solution in the dialysate pulls fluid out of the blood through a semipermeable membrane. Then, a normal dialysate solution is used to remove waste products. The two-stage process helps avoid pulling too much fluid too quickly and bottoming out the patient's pressure.

Specializes in Dialysis.

Or "dry UF". The blood is still traveling past a semi permeable membrane but there isn't any dialysate flowing by on the other side. Water from the blood can still pass through based on the hydrostatic pressure applied by the machine. Just curious, are they really asking these sort of questions on nursing boards?

Specializes in Nephrology, Dialysis, Plasmapheresis.
\ said:
I am new graduate and I am studying to take the BONENT exam. I am confused about the difference between sequential and ultrafiltration? I understand that sequential means to remove excess salt and fluid. Isn't that what ultrafiltration is doing as well? I also understand that UF/SEQ are to pull fluid onlythere is no blood being cleansed. Is this correct?

Basically different ways of saying the same thing. Some doctors write "UF only", some write "sequential treatment", some write "PUF". PUF= pure ultrafiltration. All the same. Fluid removal only and no hemodialysis.

Specializes in Nephrology, Dialysis, Plasmapheresis.

She said she was taking the BONENT exam. My question is, as a new graduate, is this even allowed? I took the NNCC certification.

Thanks I appreciate you taking the time to answer my question. :) I wanted to make sure I am understanding what I am reading and researching while I study for the exam.

Thank you also for your input, I appreciate it! I haven't taken the exam as yet, I am studying for it currently.

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