Dialysis and Renal Tranpsplant

Question 1

Indications for dialysis

Answer 1

A – Acidosis (severe and not responding to treatment)

E – Electrolyte abnormalities (severe and unresponsive hyperkalaemia)

I – Intoxication (overdose of certain medications)

O – Oedema (severe and unresponsive pulmonary oedema)

U – Uraemia symptoms such as seizures or reduced consciousness

Question 2

Indications for long term dialysis

Answer 2

End stage renal failure (CKD stage 5)

Any of the acute indications continuing long term

Question 3

Options for dialysis

Answer 3

Continuous Ambulatory Peritoneal Dialysis

Automated Peritoneal Dialysis

Haemodialysis

Question 4

How to decide on most suitable dialysis?

Answer 4

Patient preference

Lifestyle factors

Co-morbidities

Individual differences regarding risks

Question 5

How does peritoneal dialysis work?

Answer 5

Uses the peritoneal membrane as the filtration membrane

Special dialysis solution containing dextrose is added to peritoneal cavity

Ultrafiltration occurs from the blood, across the peritoneal membrane, in to the dialysis solution

Involves a Tenckhoff catheter, used for inserting and removing the dialysis solution

Question 6

What is Continuous Ambulatory Peritoneal Dialysis?

Answer 6

Dialysis solution is in the peritoneum at all times

various regimes for changing the solution

E.g 2 litres of fluid is inserted into the peritoneum and changed four times a day

Question 7

What is automated dialysis?

Answer 7

Peritoneal dialysis occurring overnight

Machine continuously replaces dialysis fluid in the abdomen overnight to optimise ultrafiltration

It takes 8-10 hours

Question 8

What are the complications of peritoneal dialysis?

Answer 8

Bacterial peritonitis - infusions of glucose = bacterial growth

Peritoneal sclerosis

Weight gain

Ultrafiltration failure - patient starts to absorb the dextrose in the filtration solution. This reduces the filtration gradient making ultrafiltration less effective

Psychosocial effects

Question 9

How does haemodyalysis work?

Answer 9

Blood filtered by a haemodialysis machine

Typical regime might be 4 hours a day for 3 days a week

Need good access to an abundant blood supply. The options for this are:
Tunnelled cuffed catheter
Arterio-venous fistula

Question 10

What is a tunnelled Cuffed Catheter?

Answer 10

Tube inserted into the subclavian or jugular vein with a tip that sits in the superior vena cava or right atrium

Two lumens - exit and entrance

Dacron cuff” surrounds the catheter. It promotes healing and adhesion of tissue to the cuff, making the catheter more permanent

Main complications are infection and blood clots within the catheter

Question 11

What is an A-V Fistula?

Answer 11

Artificial connection between an artery to a vein

Bypasses the capillary system and allows blood to flow under high pressure from the artery directly into the vein

Provides a permanent, large, easy access blood vessel with high pressure arterial blood flow

Requires a surgical operation and a 4 week to 4 month maturation period without use

Can be:
Radio-cephalic
Brachio-cephalic
Brachio-basilic (less common and more complex operation)

Question 12

How to examine an A-V fistula?

Answer 12

Skin integrity

Aneurysms

Palpable thrill (a fine vibration felt over the anastomosis)

Stereotypical “machinery murmur” on auscultation

Question 13

A-V fistula complications

Answer 13

Aneurysm

Infection

Thrombosis

Stenosis

STEAL syndrome

High output heart failure

Question 14

What is STEAL Syndrome?

Answer 14

Inadequate blood flow to the limb distal to the AV fistula

AV fistula “steals” blood from the distal limb

Causes distal ischaemia

Question 15

How can a fistula lead to HF?

Answer 15

Blood is flowing very quickly from the arterial to the venous system through the fistula

Rapid return of blood to the heart

Increases the pre-load in the heart (how full the heart is before it pumps)

This leads to hypertrophy of the heart muscle and heart failure

Question 16

How long with transplantation extend someones life for/

Answer 16

Avg 10 years

Question 17

How are patients matched for a kidney transplant?

Answer 17

Matches based on the human leukocyte antigen (HLA) type A, B and C on chromosome 6

Recipients can receive treatment to desensitise them to the donor HLA when there is a living donor

The less they match, the more likely the transplant is to fail

Question 18

Where will the new kidney be placed?

Answer 18

Patients own kidneys left in place

Donor kidney is placed anterior in the abdomen and can usually be palpated in the iliac fossa area

Donor kidney’s blood vessels are connected (anastomosed) with the patient’s pelvic vessels, usually the external iliac vessels

Question 19

What medications should a patient take post renal transplant?

Answer 19

Life long immunosuppression

Usually:

• Tacrolimus
• Mycophenolate
• Prednisolone

Other possible immunosuppressants:

• Cyclosporine
• Sirolimus
• Azathioprine

Question 20

What are the complications of renal transplant?

Answer 20

Complications relating to the transplant:

Transplant rejection (hyperacute, acute and chronic)
Transplant failure
Electrolyte imbalances

Complications related to immunosuppressants:

Ischaemic heart disease
Type 2 diabetes (steroids)
Infections are more likely and more severe
Unusual infections can occur (PCP, CMV, PJP and TB)
Non-Hodgkin lymphoma
Skin cancer (particularly squamous cell carcinoma)