Hemo… hemowhat exactly?

Hemodialysis! “Hemo” means blood. When kidneys fail, the body is no longer able to filter waste from that blood (End Stage Renal Disease). Hemodialysis picks up where your kidneys left off by using a machine to clean your blood instead. This machine, called a dialyzer, takes small amount of blood at a time and cleans it while monitoring important vitals like blood pressure.

Interested in how this “artificial kidney” machine works? Read on!

Ok listen up! Hemodialysis uses two main principles.

DIFFUSION
Tiny traffic cop
CONVECTION
Like washing dirt from your driveway
  • Membrane has little pores
  • Allows small molecules like urea, creatinine and electrolytes
  • Stops proteins and red blood cells
  • Diffuses into LOW concentration of dialysate (fluid used in machine)
  • Waste is ‘trapped’ by the dialysate and removed from blood
  • Dialysis uses flowing fluid
  • This creates ‘drag’ aka convection
  • Waste is naturally washed away with the current

Sounds interesting… but if MY kidney can’t do it, how can YOU?

The dialysis machine hooks up to your bloodstream through a catheter, fistula or graft that is surgically placed (and needs to be cleaned regularly). The dialyzer works its magic with a solution of purified water called dialysate. Ok, so it’s more biology than magic…dialysate mimics normal kidney function by buffering acid, removing salt and water, which normalizes your body’s electrolytes.

We can set the dialysis machine to remove the water weight you’ve gained. Water retention is a common issue with dialysis patients, so hemodialysis can come to the rescue!

Fistula? Graft? Catheter? Huh…? Please explain!

Reliable access to your bloodstream is the cornerstone of dialysis therapy. Removing and replacing blood is a delicate process, so your access site is your lifeline. Depending on your health and the strength of your veins, you and your vascular surgeon can decide which type (fistula, graft, or catheter) is best for you. Catheters are bad news long term because they increase risk for infections and blood clots. If using one, arrange for your surgeon to place a fistula or graft ASAP.

Fistula (AVF)
Whoo hoo #1!
Graft (AVG)
Could be better
Catheter
Upgrade ASAP
  • Optimal blood flow
  • Lowest infection risk
  • Surgeon connects arteries to a vein under the skin of upper/lower arm
  • 2-3 month healing time
  • Nurse places (2) needles into fistula 1: Takes blood from artery 2: Blood back to vein
  • Second best choice
  • Same as fistula, but instead of vein, uses soft tubing inserted under the skin by surgeon
  • Slightly less healing time
  • Slower blood flow
  • Highest infection risk
  • Y-shaped tube placed in neck/chest/groin, connected to central vein, and exits through skin
  • Can be used immediately
  • Temporary
  • Used when blood vessels are not strong enough

After all this work putting it in, how do I take care of my new fistula/graft?

  • Wash your fistula/graft with soap daily! That means EVERY DAY!
  • Feel the pulse or vibration daily (if missing call doctor)
  • No IV lines on that arm
  • Don’t sleep on it
  • Don’t use that arm for BP
  • Don’t let anyone other than your DIALYSIS NURSE use it to draw blood
  • Try not to injure that arm
  • No scratching
  • No jewelry/tight clothes over it

What should I watch out for?

Watch out for blood clots, infection, aneurysm, local bleeding and dialysis associated steel syndrome. Steel syndrome happens when your AVF/AVG affects surrounding areas. For example, an AVF in the wrist can cut off blood flow to fingers, which changes skin color and reduces pulse.

Call your Doctor IMMEDIATELY if…

  • You don’t feel a vibration (25% of hospital admissions in the dialysis population are related to their access)
  • Your skin is red
  • You notice any discharge or pus
  • Anything about the access concerns you