Renal replacement therapy

Question 1

What is meant by renal replacement therapy?

Answer 1

Peritoneal dialysis
Haemodialysis
Transplantation

Question 2

When do patients required renal replacement therapy?

Answer 2

The process for dialysis or transplantation is complicated, and the doctor will begin to plan for such eventualities when the GFR is approx. 20. This roughly equates to 20% kidney function. Most people will start dialysis when their GFR is below 12.

New guidelines consider the patients GRF but also whether or not they have symptoms of kidney failure.

These symptoms include:
 Severe fatigue
 Nausea
 Decreased appetite
 Shortness of breath 

However, co-morbidities can obscure this criterion as the symptoms listed above may be due to co-morbidities and not renal failure.

Question 3

What is meant by haemodialysis?

Answer 3

Blood is passed through an artificial kidney (‘a dialyser’). This is usually done for 4 hours, 3 times a week and requires frequent access to the blood.

Often patient will require a fistula to ensure access is readily available. A fistula is created surgically but connecting and artery and a vein in the arm. This can take up to 3 months to be ready for use.

Occasionally, haemodialysis can be done at home, which is sometimes more convenient for patients. But, most of the time HD is performed in a hospital setting.

Question 4

What is meant by peritoneal dialysis?

Answer 4

PD is when the blood is cleaned through a lining in the abdomen called the peritoneum. A tube is inserted into the peritoneum and dialysate solution enters the peritoneum over several hours. The solution slowly diffuses waste products out of the fluid and is drained away. This exchange generally takes 20-30 minutes.

Question 5

What are the absolute and relative contraindications for haemodialysis?

Answer 5

Absolute:
–> Inability to achieve suitable vascular access

Relative:

• -> Severe dementia
• -> Severe heart failure
• -> Bleeding disorders
• -> Low blood pressure
• -> Severe active psychotic disorder

Question 6

What are the absolute and relative contraindications for peritoneal dialysis?

Answer 6

Absolute:

• -> Inflammatory bowel disease (active)
• -> Ischaemic bowel
• -> Acute diverticulitis
• -> Abdominal abscess
• -> Pregnancy 3rd trimester

Relative:

• -> Abdominal hernias
• -> Stomas/VP shunt
• -> Previous multiple abdominal operations
• -> Blind (unless having assisted APD)
• -> Poor manual dexterity (unless assisted)
• -> Obesity
• -> Severe dementia
• -> Severe nephrotic range proteinuria
• -> Severe obstructive airway disease
• -> Poor hygiene
• -> Severe active psychotic disorder

Question 7

How do you explain dialysis to a patient?

Answer 7

Dialysis is a procedure to remove waste products and excess fluid from the blood when the kidneys stop working properly. It often involves diverting blood to a machine to be cleaned.

Normally, the kidneys filter the blood, removing harmful waste products and excess fluid and turning these into urine to be passed out of the body.

If your kidneys aren’t working properly, for example because you have advanced chronic kidney disease (kidney failure), the kidneys may not be able to clean the blood properly. Waste products and fluid can build up to dangerous levels in your body.

Left untreated, this can cause a number of unpleasant symptoms and eventually be fatal. Dialysis filters out unwanted substances and fluids from the blood before this happens.

There are 2 type of dialysis: one called haemodialysis and one called peritoneal dialysis.

Haemodialysis is the most common type of dialysis and the one most people are aware of. During the procedure, a tube is attached to a needle in your arm. Blood passes along the tube and into an external machine that filters it, before it’s passed back into the arm along another tube.
This is usually carried out three days a week, with each session lasting around four hours.

Peritoneal dialysis uses the inside lining of your abdomen (the peritoneum) as the filter, rather than a machine. Like the kidneys, the peritoneum contains thousands of tiny blood vessels, making it a useful filtering device.
Before treatment starts, an incision is made near your belly button and a thin tube called a catheter is inserted through the incision and into the space inside your abdomen (the peritoneal cavity). This is left in place permanently.
Fluid is pumped into the peritoneal cavity through the catheter. As blood passes through the blood vessels lining the peritoneal cavity, waste products and excess fluid are drawn out of the blood and into the dialysis fluid. The used fluid is drained into a bag a few hours later and replaced with fresh fluid.
Changing the fluid usually takes about 30-40 minutes and normally needs to be repeated around four times a day. If you prefer, this can be done by a machine overnight while you sleep.

Question 8

What are the side effects fo dialysis?

Answer 8

Haemodialysis can cause itchy skin and muscle cramps. Peritoneal dialysis can put you at risk of developing peritonitis (infection of the thin membrane that surrounds your abdomen).

Both types of dialysis can make you feel exhausted.

Question 9

Which treatment is more effective?

Answer 9

The two techniques are equally effective for most people, but each has its own advantages and drawbacks. For example:

• -> haemodialysis means you’ll have four treatment-free days a week, but the treatment sessions last longer and you may need to visit hospital each time
• -> peritoneal dialysis can be done quite easily at home and can sometimes be done while you sleep, but it needs to be done every

Question 10

How should you examine a fistula?

Answer 10

Introduction, ask permission and wash hands

Look

• -> Where is the fistula? Radiocephalic/ Brachiocephalic/ Brachiobasilic
• -> Is there any evidence of any previous fistulae? Look over both arms
• -> Is there evidence of any recent use? Dressings? Needle sites?
• -> Any signs of aneurysms? Haematomas? Infection?
• -> Is there any evidence of swelling of the fistula arm or collateral veins that may suggest central vein stenosis?
• -> Is there any evidence of cold/blue hands distal to the fistula which may suggest steal syndrome?

Listen to the fistula
–> Using a stethoscope listen along the length of the fistula for a bruit

Feel the fistula

• -> Can you feel a thrill?
• -> If the fistula is pulsatile this may suggest a problem with the fistula outflow.