Dialysis and Transplantation

Question 1

Which toxins can dialysis remove that build up in end-stage kidney disease?

Answer 1

Urea
Potassium
Sodium
Creatinine

Question 2

Which ion can be infused using dialysis?

Answer 2

Bicarbonate

Question 3

List the components of dialysate

Answer 3

Pure water
Sodium
Bicarbonate
Potassium
Glucose

Question 4

How is water removed from the body in dialysis?

Answer 4

Create negative pressure across membrane to suck water out (filtration)

Question 5

Dialysis is very efficient. True/False?

Answer 5

False

Not very efficient; longer treatment equals better efficiency

Question 6

What is the time schedule for haemodialysis?

Answer 6

4 hours, 3 times a week

Question 7

How much fluid, salt, potassium and phosphate is allowed during dialysis?

Answer 7

Restrict fluid - 1 litre water a day
Low salt diet
Low potassium diet
Low phosphate diet and phosphate binders with meals

Question 8

What is the gold standard for dialysis access?

Answer 8

Arteriovenous fistula, usually in arm joining brachial artery and cephalic vein

Question 9

What are the drawbacks of an AV fistula?

Answer 9

Requires maturation of 6 weeks before use
Can limit blood flow to distal arm
Thrombosis/ stenosis
Creates a shunt

Question 10

What is the alternative access for dialysis whilst the AV fistula is maturing?

Answer 10

Tunnelled venous catheter inserted into jugular/subclavian/femoral vein

Question 11

What are the drawbacks of tunnelled venous catheters?

Answer 11

High risk of infection (usually SA endocarditis/ discitis)
Damage vein
Thrombosis/ stenosis

Question 12

What can go wrong with dialysis?

Answer 12

Hypotension (underfilling of intravascular space due to removal of water)
Blood leaks
Reduced vascular access
Hyperkalaemia - cardiac arrest

Question 13

What is the alternative to haemodialysis and how does it work?

Answer 13

Peritoneal dialysis
Use peritoneal membrane for diffusion of solutes, water removal by osmosis and glucose conc. in dialysate which drains into bag afterwards

Question 14

What is the time schedule for peritoneal dialysis?

Answer 14

Continuous: 4 times a day
OR
Autonomous: Overnight (1 bag a day)

Question 15

What is the advantage of peritoneal dialysis over haemodialysis?

Answer 15

Portable - less restrictive

Question 16

What are the disadvantages of peritoneal dialysis?

Answer 16

Infection (peritonitis/ exit site due to contamination and gut bacteria translocation)
Membrane failure (can't remove water causing fluid overload)
Hernias (increased intrabdominal pressure)

Question 17

When is dialysis started based on bloods?

Answer 17

Resistant hyperkalaemia
GFR less than 5 (following preparation!)
Unresponsive acidosis
Uraemia (UR >40)

Question 18

Which syndrome can result in the short-term following haemodialysis?

Answer 18

Disequilibrium syndrome involving cerebral oedema and seizures

Question 19

In end-stage kidney disease, survival with dialysis decreases with increasing age. True/False?

Answer 19

True

Question 20

Kidney is taken out in transplant. True/False?

Answer 20

False

Leave kidneys and put new kidney in lower iliac fossa/pelvis

Question 21

Which donor blood groups are compatible with recipient with blood group O?

Answer 21

O

Question 22

Which donor blood groups are compatible with recipient with blood group A?

Answer 22

O

A

Question 23

Which donor blood groups are compatible with recipient with blood group B?

Answer 23

O

B

Question 24

Which donor blood groups are compatible with recipient with blood group AB?

Answer 24

O

AB

Question 25

People with blood group O have which antibodies? What is the effect of this?

Answer 25

Anti-A and anti-B antibodies, so can only receive donor from person with blood group O

Question 26

What are HLA proteins? List the main types

Answer 26

Cell surface proteins that activate the immune system in graft rejection HLA A, B and DR

Question 27

Which HLA are class 1?

Answer 27

HLA A | HLA B

Question 28

Which HLA are class 2?

Answer 28

HLA DR

Question 29

1 HLA is inherited from each parent. True/False?

Answer 29

True

Question 30

A patient who has been exposed to non-self HLA Ag forms antibody to it and this leads to rejection. What are the main ways HLA Ag exposure can occur?

Answer 30

Blood transfusion Pregnancy Previous transplants

Question 31

Outline the process of graft rejection

Answer 31

HLA antigen binds to dendritic cell which expresses MHCII that activates CD4 cells, which enable B cell proliferation (produce antibodies to graft) and CD8/NK production which directly attack graft

Question 32

Describe the 3 forms of graft rejection

Answer 32

Hyperacute: preformed Ab to transplant, minutes (black kidneys) Acute: T/B-cell mediated, early on Chronic: immune/vascular deterioration of transplant

Question 33

Acute graft rejection may be treatable with immunosuppression. List some medication

Answer 33

Steroids MMF Cyclosporin Tacrolimus

Question 34

Which class of drug includes cyclosporin and tacrolimus? How do they work?

Answer 34

Calcineurin inhibors | Inhibit activation of CD4 cells (thus reduce NK/CD8/B-cell proliferation)

Question 35

List some side effects of calcineurin inhibitors

Answer 35

``` Renal dysfunction Hypertension Diabetes Tremors Drug interactions ```

Question 36

How do azathioprine and mycophenolate help in immunosuppression?

Answer 36

Block purine synthesis - suppress proliferation of B and T cells Can cause leucopenia, GI upset, anaemia

Question 37

Which drug does azathioprine notably, infamously, dangerously interact with?

Answer 37

Allopurinol

Question 38

List the main types of donor kidney

Answer 38

Brain dead patient Cardiac dead patient Live donor (familial) Kidney-pancreas dual transplant (diabetics)

Question 39

Allocation of kidneys in UK is based on tissue typing and then time on donor list. True/False?

Answer 39

True

Question 40

List absolute contraindications to transplantation of kidney

Answer 40

``` Malignancy (active or within last 2-5 years) Active HCV/ HIV Untreated TB Severe IHD/ airway disease/ PVD Active vasculitis Hostile bladder ```

Question 41

List people at risk of progression to dialysis

Answer 41

``` Inheritable renal conditions CKD/AKI CVD/ hypertension Proteinuria Diabetes Smoking Chronic NSAID use Untreated UT obstruction ```

Question 42

What are the 3 key principles of dialysis?

Answer 42

DIFFUSION: movement of solutes from high to low conc. CONVECTION: movement of water in response to pressure gradient (ultrafilitration) ADSORPTION: plasma proteins to membrane and absorb protein-bound solutes

Question 43

What is the difference between haemodialysis and haemodiafiltration?

Answer 43

Increased connective force, increased volume of pressure driven ultrafiltrate (SOLUTE DRAG)

Question 44

How do you explain haemodialysis to a patient?

Answer 44

Insert fistula to act as an artifical kidney putting good things in (nutrients, vitamins) and taking waste out, involves minor procedure

Question 45

How do you explain peritoneal dialysis to a patient?

Answer 45

Insert tube into tummy which connects to a machine overnight - puts fluid in which is left for a few hours and drained - can do it at home, giving patients more freedom

Question 46

How long after transplantation does a patient get the survival benefit?

Answer 46

3 months

Question 47

List complications of renal transplantation

Answer 47

``` Bleeding Arterial or venous stenosis Wound infection Lymphocele Ureteric stricture ```

Question 48

State the main side effect of immunosuppression and list types

Answer 48

Bacterial (UTI/ URTI) Prophylaxis for PCP Fungal Viral (CMV, HSV, BK)