Renal Replacement Therapy - Dialysis and Transplant Flashcards Preview

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Flashcards in Renal Replacement Therapy - Dialysis and Transplant Deck (63)
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1
Q

What is end-stage renal disease - HCFA definition?

A

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 transplantation

2
Q

What is uraemia?

A

The syndrome of advanced CSK

3
Q

What are the symptoms of uraemia?

A

Until stage 4 or 5 CKD the patient may be asymptomatic
Uraemia can involve almost every organ system but the earliest and cardinal symptoms are malaise and fatigue

Other symptoms:
Nausea 
Vomiting 
Anorexia 
Weight loss 
Muscle cramps
Pruritis 
Visual disturbances
Increased thirst
Exacerbation of CVS conditions 
Mental status changes
4
Q

What are the signs of uraemia?

A
Anaemia
Acidaemia 
Electrolyte abnormalities
Hypertension
Fluid retention 
Muscle wasting 
Arrhythmias 
Exacerbation of CVS conditions 
Mental status changes
5
Q

What is renal replacement therapy?

A

The means by which life is sustained in patients suffering from end-stage renal disease
This is usually indicated when eGFR is less than 10ml/min

6
Q

What are the types of renal replacement therapy?

A

Haemodialysis
Peritoneal dialysis - continuous ambulatory peritoneal dialysis (CAPD, or intermittent peritoneal dialysis (IPD)
Renal transplant

7
Q

What is dialysis?

A

A process whereby the solute composition of a solution, A, is altered by exposing solution A to a second solution, solution B, through a semi-permeable membrane

8
Q

What are the main principles of dialysis?

A

Diffusion

Ultrafiltration - pressure gradient across the membrane is increased

9
Q

What does an increase in transmembranous pressure allow?

A

Allows water to be pushed across the membrane and therefore allows removal of excess water

10
Q

What are the pre-requisites for dialysis?

A

Semi-permeable membrane - artificial kidney in HD or peritoneal membrane
Adequate blood exposure to the membrane - extracorporeal blood in HD, mesenteric circulation in PD
Anticoagulation for HD
Dialysis access - vascular in HD, or peritoneal in PD

11
Q

What are the access options for haemodialysis?

A

Arteriovenous vistula - anastomosis of artery and vein, usually the end of vein to the side of artery
This short-circuits arterial blood into the vein to increase the size and thickness of the vein wall after around 6 weeks

Arteriovenous prosthetic graft

Tunnelled venous catheter - subcutaneous so cannula doesn’t come straight out of the neck, removed via subcutaneous tunnel

Temporary venous catheter

12
Q

What are the complications of haemodialysis?

A
Clotting of vascular access
Hypotension and cramps
Cardiovascular problems
Heparin-related problems
Allergic reactions to dialysers and tubing 
Catastrophic dialysis accidents (rare)
13
Q

What are the restrictions for dialysis patients?

A

Fluid restriction - dictated by urine output, interdialytic weight gain
Dietary restriction - sodium, potassium and phosphate

14
Q

How is peritoneal dialysis done?

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

15
Q

How often is continuous ambulatory peritoneal dialysis done?

A

4 exchanges a day

16
Q

When is automated peritoneal dialysis done?

A

Cycles done at night while patient is asleep

17
Q

What is the main advantage and disadvantage of peritoneal dialysis?

A

Advantage of being done at home

Disadvantage of large infection risk

18
Q

What does the dialysate used for PR contain?

A

A balanced concentration of electrolytes

19
Q

What is the most common osmotic agents used for ultrafiltration of fluid?

A

Glucose

20
Q

What are dwell times adjusted according to?

A

Transport characteristics - peritoneal transport characteristics can vary from high transporter to low transporter

21
Q

What are the complications of peritoneal dialysis?

A
Peritonitis 
Exit site infection 
Ultrafiltration failure 
Encapsulating peritoneal sclerosis 
Tunnel infection 
Abdominal wall hernia
22
Q

What are the types of peritonitis seen due to PD?

A

Gram positive - skin contaminant
Gram negative - bowel origin
Mixed - suspect complicated peritonitis e.g. due to perforation

23
Q

What are the indications for commencing dialysis in end-stage renal disease?

A

Advanced uraemia, usually GFR < 5-10ml/min
Severe acidosis, bicarbonate < 10 mmol/l
Hyperkalaemia, K > 6 mmol/l
Fluid and salt retention not controlled with diuretics

24
Q

What is the recommended protein dietary intake for a dialysis patient?

A

1.2-1.4 g/kg/24 hours

25
Q

What is the recommended calorie dietary intake for a dialysis patient?

A

35-40 kcal/kg/24 hours

26
Q

What vitamins are supplemented in dialysis patients?

A

Water soluble vitamins

27
Q

How is phosphate controlled in dialysis patients?

A

Dietary phosphate restricted

Use of phosphate binders

28
Q

What is the fluid restriction in dialysis patients?

A

Haemodialysis patients usually restricted to 500-800 ml/24 hours
Intake allowed = urine output + insensible loss

Peritoneal dialysis usually more liberal intake as continuous ultrafiltration is often achieved

29
Q

What drugs are usually prescribed for dialysis patients?

A
Erythropoietin injections 
Either alpha vitamin D or calcitriol
Phosphate binders with meals
Iron supplements
Water soluble vitamins
Possibly antihypertensives
Possibly lipid-lowering drugs
30
Q

What are the factors that determine the choice of dialysis modality?

A
Patient-related
Cost
Remuneration 
Perceptions of effectiveness
Patient choice
31
Q

What are the limitations of dialysis?

A

Not a complete substitute for the kidneys but only means of keeping patients with end-stage renal disease alive

32
Q

How is renal transplantation carried out?

A

Transplanted kidney is placed into iliac fossa and anastomosed to the iliac vessels
Native kidneys usually remain in situ

33
Q

What are the indications for native nephrectomy?

A

Size e.g. polycystic kidneys

Infection e.g. chronic pyelonephritis

34
Q

When are deceased donors used for renal transplantation?

A

Donation after brain death or after cardiac death (according to criteria)

35
Q

What living donors can be used for renal transplantation?

A

Living related donor
Living unrelated donor - spousal, altruistic, Paired/pooled
ABO incompatible/HLA incompatible

36
Q

What are the brain death criteria which must be met for a patient to be allowed to donate their kidneys?

A

Coma, unresponsive to stimuli
Apnoea off ventilator despite build up of CO2
Absence of cephalic reflexes e.g. pupillary, oculocephalic, oculovestibular, corneal, gage, purely spinal reflexes may still be present
Body temperature above 34 degrees Celsius
Absence of drug intoxication - ethanol, anaesthetic agents or paralysing drugs

37
Q

When are extended criteria used for deceased donor kidneys?

A

Donor aged > 60

Donor aged > 50 with history of hypertension or stroke as cause of death

38
Q

What are the features of donation using living unrelated kidney donor?

A

Usually poorly matched
Heavier immunosuppression
Higher rate of sensitisation if it fails
High degree of donor/recipient satisfaction

39
Q

What are the outcomes of kidney donation?

A

Life span of donors is similar to general population
No increase in ESRD risk, rates of ESRD reduced
Good quality of life
Uninephrectomy leads to compensatory increase in GFR of remaining kidney to 70% of pre-donation values
Compensatory increase is greater in younger donors

40
Q

What are the complications of renal transplantation?

A

Rejection - cell mediated, humeral (Ab mediated)
Cardiovascular - underlying renal disease, CRF, hypertension, hyperlipidaemia, PT diabetes
Infective - bacterial, viral, fungal
Malignancy - skin, lymphoma, solid cancers

41
Q

What are the types of acute rejection following renal transplantation?

A

Hyperacute rejection - pre-existing alloreactivity to donor
Acute T cell-mediated rejection
Acute antibody mediated rejection

42
Q

What are the features of type I acute rejection?

A

Lymphocyte infiltrate

Tubilitis

43
Q

What are the features of type II acute rejection?

A

Endarteritis

Endothelialitis

44
Q

What are the features of humeral rejection?

A

Neutrophil infiltration - glomeruli, peritubular capillaries
Endothelial swelling
Positive C4d - peritubular capillaries

45
Q

What immunosuppression can be used in renal transplantation?

A

Non-specific e.g. prednisolone, azathioprine
T-cell activation specific e.g. cyclosporine, tacrolimus, MMF
mTOR inhibitors e.g. rapamycin
Anti-IL2 receptor antibodies
T-cell antibodies e.g. ATG, OKT3

46
Q

What is the side effect of sicrolimus (rapamycin)?

A

Hyperlipidaemia

47
Q

What are the side effects of CNIs?

A

Hyperglycaemia
Hypertension
Chronic kidney disease

48
Q

What is the side effect of lymphoid depletion?

A

Malignancy

49
Q

What is the side effect of glucocorticoids and anti-metabolites e.g. MMF, AZA?

A

Infections

50
Q

Why is cytomegalovirus important in renal transplantation?

A

Major problem following transplant
Most common opportunistic infection after transplant
Incidence of clinically apparent CMV disease between 20% and 80%

51
Q

What are the complications of cytomegalovirus infection?

A
High mortality if untreated - up to 90% 
CMV syndrome
Gastroenteritis 
Nephritis 
Hepatitis 
Pneumonitis 
Retinitis
52
Q

What does BK virus cause?

A

Nephropathy in renal transplant recipients

Haemorrhagic cystitis in AIDs patients and in those who have undergone bone marrow transplantation

53
Q

What does JC virus cause?

A

Associated with progressive multifocal leukoencephalopathy

54
Q

How do human polyoma viruses infect cells?

A

Viral particles bind to specific cell surface receptors on a permissive cell - T antigens early in the infection cycle
These bind intracellular proteins to promote viral replication and block tumour suppressor proteins

55
Q

What are the clinical manifestations of BK virus infection?

A

Renal transplantation

  • ureteral stenosis
  • interstitial nephritis
  • end stage renal failure

Bone marrow transplantation

  • haemorrhage cystitis
  • pneumonitis
  • hepatitis

AIDS

  • nephritis
  • end stage renal failure
  • retinitis
  • meningoencephalitis
  • pneumonitis
56
Q

What are the risk factors for BK virus Allograft Nephropathy ?

A

Intensity of immunosuppression - tacrolimus, mycophenolate mofetil, antilymphocyte globulins

Patient determinants

  • older age
  • male
  • white ethnicity
  • DM
  • negative BKV serostatus

Organ determinants

  • graft injury
  • HLA mismatches
  • ureteral stents

Viral determinants
- changes in epitopes of viral capsid protein VP-1

57
Q

What is the outcome of BKAN?

A

Allograft dysfunction, loss of graft in 45-80%

58
Q

What is the treatment of BKAN?

A

Modification of immunosuppression

Antiviral therapy - cidofovir +/- probenecid, leflunomide

59
Q

What is the relative risk of colon, lung or breast cancer after renal transplantation?

A

2%

60
Q

What is the relative risk of testicular or bladder cancer after renal transplantation?

A

3%

61
Q

What is the relative risk of melanoma, leukaemia or cervical cancer after transplantation?

A

5%

62
Q

What is the relative risk of renal malignancy after transplantation?

A

15%

63
Q

What is the relative risk of non-melanoma skin cancer, Kaposi sarcoma or non-Hodgkin lymphoma after transplantation?

A

20%