Dialysis in a nutshell (A semi permeable nutshell)

So. Renal Replacement Therapy. aka Dialysis.

I adore Joyce. She can take 15 pages of impossible-to-understand text and just….reword it in to something so simple I can’t believe that I didn’t get it in the first place!

Three types of dialysis: HD (hemodialysis), PD (peritoneal dialysis), KT (kidney transplant)

Hemodialysis is where they either cannulate (make an external shunt) a large vein and a large artery that are near each other, or they create a fistula (sew together a large artery and a large vein below the surface of the skin so you can create one blood vessel for withdrawal and returning of blood.) (these are kind of cool, in a sense, cuz they feel like a cat purring under the skin a little bit.) It can be done on an OP basis or at a dialysis center. Usually takes 4-8 hrs, 1-3 times a week. But lots of centers are open 24hrs, so pt can just go sleep while it’s being done.

Peritoneal uses the membrane in the abdomen. Takes a lot longer cuz there’s not as much control in terms of filtration, etc. You fill the peritoneal cavity, let the diasylate dwell for 4-8hrs, and then drain it. (with Hemodialysis, a machine is doing the filtration, so you can control the rate better). BUT, PD (some forms of it) is machine free, which gives the pt a LOT more mobility and freedom. And it doesn’t require vascular access, so less chance for sepsis. But more chance for peritonitis.

Who needs dialysis?: A, E, I, O, U.
people with–
A= acid base imbalances
E= electrolyte problems
I= intoxications (acute ETOH poisoning, acetomeniphen/tylenol OD, ingestion of poisonous substances)
O= overload of fluids
U= uremic signs and systems (uremea is kidney dysfunction)
(also ppl with extensive burns)

What IS dialysis?: Dialysis is a teabag.

Yup. A teabag.

1. Diffusion- the passage of particles thru a semi-permeable membrane
-tea particles flow (diffuse) out of teabag

2. Osmosis- movement of fluid across semi-permeable membranes from lower to higher concentration
-water flows into teabag

(these can and do happen at the same time, else you wouldn’t get a cup of tea!)

3. Filtration- passage of fluid thru a semi-permeable membrane
-teabag drips when you take it out of cup

4. Ultrafiltration- pressure helping fluid squeeze thru the membrane
-like when you put the teabag on your spoon and wrap the tag around it and squeeze it, to get more out & make the tea stronger.

So. There’s that.

Lah. Ok. Done with dinner. Time to get back to studying. wee….