renal replacement therapy

Question 1

what are the functions of the kidneys?

Answer 1

Excretion of nitrogenous waste products
Maintenance of acid and electrolyte balance
Control of blood pressure
Drug metabolism and disposal
Activation of vitamin D
Production of erythropoietin

Question 2

what is end stage renal disease?

Answer 2

irreversible damage to a person’s kidneys so severely affecting their ability to remove or adjust blood wastes that, to maintain life, he or she must have either dialysis, or a kidney transplant

Question 3

what are clinical features of advanced CKD?

Answer 3

Until CKD stage 4 or 5 the patient may be asymptomatic

The syndrome of advanced CKD is called uraemia

Uraemic symptoms can involve almost every organ system but the earliest and cardinal symptom is malaise and fatigue

Question 4

is CKD ussually symptomatic?

Answer 4

no

Question 5

when is RRT ussually indicated?

Answer 5

when eGFR <10ml/min

Question 6

what are different types of renal replacement therapy?

Answer 6

Renal transplant

Haemodialysis
Home haemodialysis
Satellite / hospital haemodialysis

Peritoneal dialysis
Continuous ambulatory peritoneal dialysis (CAPD)
Intermittent peritoneal dialysis (IPD)

Conservative Kidney Managemen

Question 7

what is dialysis?

Answer 7

Dialysis is a process whereby the solute composition of a solution, A, is altered by exposing solution A to a second solution, B, through a semipermeable membrane.

Question 8

what is the first principle of dialysis?

Answer 8

diffusion

Question 9

what is the second principle of dialysis?

Answer 9

ultrafiltration

Question 10

what are pre-requisites for dialysis?

Answer 10

Semipermeable membrane (artifical kidney in haemodialysis or peritoneal membrane)

Adequate blood exposure to the membrane (extracorporeal blood in haemodialysis, mesenteric circulation in PD)

Dialysis Access vascular in haemodialysis, peritoneal in PD

Anticoagulation in hemodialysis

Question 11

what are permanent haemodialysis accesses?

Answer 11

Arteriovenous fistula
AV prosthetic graft

Question 12

what are temporary haemodualysis accesses?

Answer 12

Tunnelled venous catheter
Temporary venous catheter

Question 13

how does dialysis work?

Answer 13

Question 14

what are restrictions for dialysis patients?

Answer 14

Dictated by residual urine output

Interdialytic weight gain

Potassium

Sodium

Phosphate

Question 15

describe the process of haemodialysis?

Answer 15

Question 16

what is peritoneal dialysis?

Answer 16

A balanced dialysis solution is instilled into the peritoneal cavity via a tunnelled, cuffed catheter, using the peritoneal mesothelium as a dialysis membrane

After a dwell time the fluid is drained out and fresh dialysate is instilled

Continuous Ambulatory Peritoneal Dialysis (CAPD),
Automated Peritoneal Dialysis (APD)
Hybrid

Question 17

what does dialysis fluid contain?

Answer 17

The dialysate contains a balanced concentration of electrolytes

Glucose is the most common osmotic agent for ultrafiltration of fluid

Question 18

The peritoneal transport characteristics can vary from high transporter to low transporter
Dwell times can be adjusted according to transport characteristics

Question 19

what is the regime for CAPD?

Answer 19

Question 20

what is the regime for APD?

Answer 20

Question 21

complications of peritoneal dialysis?

Answer 21

Exit site infection

PD peritonitis
Gram positive – skin contaminant
Gram negative – bowel origin
Mixed – suspect complicated peritonitis eg perforation

Ultrafiltration failure

Encapsulating peritoneal

Question 22

what are indications for dialysis in end stage renal disease?

Answer 22

Advanced uraemia, (GFR 5-10 ml/min)
Severe acidosis (bicarbonate <10 mmol/l)
Treatment resistant hyperkalaemia (K >6.5 mmol/l)
Treatment resistant fluid overload

Nephrologist’s clinical judgment is important

Question 23

what is the fluid balance for haemodialysis?

Answer 23

Usually restricted to 500-800 ml/24 hours intake allowed = urine output +insensible loss

Question 24

what is the fluid balance for Peritoneal dialysis?

Answer 24

Usually more liberal intake as continuous ultrafiltration is often achieved

Question 25

what are dialysis related drugs?

Answer 25

Anaemia
Erythropoietin injections
IV iron supplements
Renal Bone Disease
Activated Vitamin D (eg calcitriol)
Phosphate binders with meals (CaCo3)
Heparin
Water soluble vitamins
? antihypertensives

Question 26

what are complications of haemodialysis?

Answer 26

Cardiovasular problems
Intra-dialytic hypotension and cramps
Arrythmias

Coagulation
Clotting of vascular access
Heparin related problems

Other
Allergic reactions to dialysers and tubing
Catastrophic dialysis accidents (rare)

Question 27

what are complications of peritoneal dialysis?

Answer 27

Infection
Exit site infection
Tunnel infection
Peritonitis

Mechanical
Tube malfunction
Abdominal wall herniae

Ultrafiltration problems

Question 28

how is the decision for choice of dialysis modality chosen?

Answer 28

Patient choice – most important
Education
Shared decision making

Patient related
Perceptions of effectiveness
(Cost and remuneration)

Question 29

what are limitations of dialsysis?

Answer 29

Dialysis of whatever type is a woeful substitute for the kidneys

However it is the only means of keeping patients with ESRD alive
But might not be right for everyone

Question 30

what is conservative kidney management?

Answer 30

Supportive care
Priority for symptomatic management
Holistic multi-professional approach
Anticipatory care planning

Randomised control trial ongoing for dialysis versus CKM for older adults with co-morbidity