Dialysis

Question 1

When does a patient need to start dialysis?

Answer 1

When the risks of uremic complications exceed the risks of dialysis therapy.

Question 2

What are possible indications for dialysis?

Answer 2

• Volume overload refractory to diuretics
• Hyperkalemia refractory to medical therapy
• Uremic pericarditis
• Uremic symptoms
  
  • Lethargy, difficulty concentrating (early)
  • Coma, seizures (late)
  • Nausea, decreased appetite
  • Uremic bleeding
• Other metabolic derangements (metabolic acidosis, severe hyperphosphatemia, calcium abnormalities)

Question 3

What form of dialysis is most common?

Answer 3

Hemodialysis (greater than 90% of patients)

Question 4

Dialysis vascular access ideally has what characteristics? (6)

Answer 4

1. Provides fast blood flow
2. Allows repeated access
3. Can be used immediately
4. Has low infection rate
5. Has long lifespan
6. Doesn’t cause morbidity

Question 5

What is an AV fistula?

Answer 5

A surgically placed access which connects a native artery to a native vein. When this happens, the vein gets thicker so that it can withstand being stuck many times. Also, this provides a fast blood flow for the dialysis.

This is typically done on the non-dominant arm.

Question 6

What are pros for using AV fistula for hemodialysis? (3)

Answer 6

1. Lowest infection rate
2. longest lifespan
3. requires fewest procedures to maintain

Question 7

What are the cons for using AV fistula for hemodialysis? (4)

Answer 7

1. Can take months to mature
2. some may never be usable for dialysis
3. risk of steal syndrome
4. needles

Question 8

What are 3 typical locations for AV fistulas?

Answer 8

1. Radiocephalic
2. Brachiocephalic
3. Brachiobasilic

Question 9

What is an AV graft?

Answer 9

Synthetic conduit between artery and vein.

Question 10

What are pros for AV grafts? (3)

Answer 10

1. can be used quicker than AV fistula
2. Good blood flows
3. lower infection rate than catheters (but higher than AVFs)

Question 11

What are cons for AV grafts (4)

Answer 11

1. High rate of stenosis, requiring interventional procedures
2. Shorter life span than AV fistula
3. Risk of steal syndrome
4. Needles

Question 12

What is a dialysis catheter?

Answer 12

This is a double lumen catheter that is typically placed in the internal jugular vein and terminates in the SVC.

Question 13

What are the pros for dialysis catheters? (3)

Answer 13

1. Immediate use
2. No needles
3. Does not require surgery

Question 14

What are the cons for dialysis catheters? (4)

Answer 14

1. Highest infection risk
2. High rate of dysfuncion/low blood flows
3. Requires insertion site care
4. Associated with high mortality in dialysis patients

Question 15

What are complications of dialysis that can happen during treatment? (5)

Answer 15

1. Muscle cramps
2. Hypotension
3. Headache
4. Chest pain
5. Air embolism (very rare)

Question 16

What bacteria most commonly causes dialysis infection?

Answer 16

Staph aureus (or other skin organisms)

Question 17

What are some limitations of dialysis?

Answer 17

• Difficulty achieving euvolemia
  
  • During in-center hemodialysis treatments, it may be difficult to remove enough volume to achieve “dry weight”
• Abnormal bone and mineral disorders
  
  • Despite regular dialysis, most patients will still exhibit hyperphosphatemia and require oral phosphorous binders.

Question 18

What are pros and cons for doing frequent or nocturnal dialysis?

Answer 18

Pros

• It can be performed at home
• longer total dialysis time per week
  
  • improved blood pressure/left ventricular hypertrophy
  • improved phosphorous control

Cons

• Associated with a higher risk of vascular access complications

Question 19

What is peritoneal dialysis?

Answer 19

Catheter is placed into peritoneal cavity and exits the abdominal wall. Fluid with a high glucose concentration is instilled in the peritoneal cavity. Water moves into the peritoneal cavity by osmosis and uremic solutes are removed by convection. Patients perform at least 3-4 exchanges per day.

This is usually done at home every day.

It’s common in other countries but not as much in the US (8% of cases)

Question 20

What is continuous ambulatory peritoneal dialysis (CAPD)?

Answer 20

It’s the type of peritoneal dialysis where the patient manually performs exchanges

Question 21

What is continuous cycling peritoneal dialysis (CCPD)?

Answer 21

It’s the type of peritoneal dialysis where a cycler machine performs exchanges at night when the patient is sleeping and leaves dialysate in the abdomen in the morning.

Question 22

What is nocturnal intermittent peritoneal dialysis (NIPD)?

Answer 22

It is the type of peritoneal dialysis where a cycler performs dialysis overnight but does not leave dialysate in the abdomen in the morning.

Question 23

What are complications for peritoneal dialysis?

Answer 23

• Infection
  
  • peritonitis (PMNs in dialysate, abdominal pain, fever)
    
    • Due to both gram positive and negative organisms
  • Exit site infections (purulence and pain at exit site)
• Catheter dysfunction/problems draining
  
  • may be due to constipation
  • may need surgical revision
• Hernias
• Metabolic complications
  
  • Hyperglycema (because you are giving a high dextrose solution)
  • Hypertriglyceridemia
  • Hypokalemia
• Scarring of the peritoneal membrane

Question 24

Compare and contrast hemodialysis vs peritoneal dialysis

Answer 24