Chronic Kidney Disease Flashcards
What is chronic kidney failure defined as?
Progressive and irreversible loss of renal function over a period of months to years
What is functioning renal tissue replaced by in chronic kidney failure?
Extra-cellular matrix
What does the replacement of functioning renal tissue by extra-cellular matrix give rise to histologically?
- Glomerulosclerosis
- Tubular interstitial fibrosis
What is the result of the replacement of functioning renal tissue with ECM?
There is progressive loss of both the excretory and hormone functions of the kidney
What are most glomerular diseases that lead to chronic renal failure characterised by?
The development of proteinuria and systemic hypertension
What are the causes of chronic kidney disease?
- Immunologic
- Infection
- Genetic
- Obstruction and reflux nephropathy
- Hypertension
- Vascular
- Systemic disease
- Cause unknown
What are the immunologic causes of chronic kidney disease?
Glomerulonephritis
What are the infectious causes of chronic kidney disease?
Pyelonephritis
What are the genetic causes of chronic kidney disease?
- Polycystic kidney disease (PCK)
- Alport’s syndrome
What systemic diseases can cause chronic kidney disease?
- Diabetes
- Myeloma
What are the stages of chronic kidney disease?
1-5
What is the GFR in stage 1 chronic kidney disease?
>90
What is the description of stage 1 CKD?
Kidney damage with normal or increased GFR
What evidence is needed to diagnose stage 1 CKD?
Other evidence of kidney damage (U/A or USS)
What % of the population have stage 1 CKD?
3.3
What is the GFR in stage 2 CKD?
60-89
What is the description of stage 2 CKD?
Kidney damage with mild GFR fall
What evidence is needed to diagnose stage 2 CKD?
Need other evidence of kidney damage (U/A or USS)
What % of the population have stage 2 CKD?
3%
What is the GFR in stage 3 CKD?
30-59
What is the description of stage 3 CKD?
30-59
Does stage 3 CKD present with symptoms?
May or may not
What % of the population have stage 3 CKD?
6%
What is the GFR in stage 4 CKD?
15-29
What is the description of stage 4 CKD?
Severe fall in GFR
Does stage 4 CKD present with symptoms?
Yes, worse than stage 3
What % of the population have stage 4 CKD?
0.2%
What is the GFR in stage 5 CKD?
<15 or RRT
What is the description of stage 5 CKD?
Established renal failure
When is dialysis started with stage 5 CKD?
<10ml/min GFR
What % of the population have stage 5 CKD?
0.1%
What systems can chronic kidney failure affect?
- Cardiovascular
- Haematology
- Bone
- CNS
- General symptoms
What cardiovascular symptoms can chronic kidney failure cause?
- Atherosclerosis
- Cardiomyopathy
- Pericarditis
What haematology symptoms can chronic kidney failure cause?
Anaemia
Why can chronic kidney failure cause anaemia?
Decreased or resistance to erythropoietin
What bone effects can chronic kidney failure have?
- Renal bone disease
- Osteitis fibrosa cystica
- Osteomalacia
- Non-bone (e.g. extra articular) calcification
How does chronic kidney failure cause osteitis fibrosa cystica?
- Decreased GFR means less phosphate is excreted, increasing its serum concentration.
- It then forms complexes with free calcium, reducing its effective serum concentration
- This stimulates the parathyroid to produce PTH, causing over activity of osteoclasts, leading to osteitis fibrosa cystica
Why does chronic kidney failure cause osteomalacia?
Damage to the kidneys means less vitamin D undergoes its 2nd hydroxylation to its active form. This also cause hyperparathyroidism and osteomalacia
What are the CNS symptoms of chronic kidney failure?
- Neuropathy
- Seizures
- Coma
What are the general symptoms of chronic kidney failure?
- Tiredness
- Breathlessness
- Restless legs
- Sleep reversal
- Seizure
- Aches and pains
- Nausea and vomiting
- Itching
- Chest pain
Are patients with CKD more likely to need dialysis or die from a CVS event?
Die from a CVS event
What is a normal GFR range?
80-120ml/min
How can renal function be expressed?
As a function of the normal GFR
How can GFR be measured?
Via insulin clearance or 24hr creatanine clearance
What needs to be done if creatanine is used to measure GFR?
Needs to be modified to estimated GFR (eGFR)
How is GFR modified to eGFR?
By an equation to take into account age, sex, gender, and ethnicity
Is creatinine a perfect maker for renal function?
No
Why is creatanine not a perfect marker for renal function?
- Someone with a GFR of 40% of normal can still have a normal creatinine level
- Only accurate in adults
- Only defines chronic kidney disease (not useful in acute renal failure)
How is the cause of CKD assessed?
- Auto-antibody screen
- Complement
- Immunoglobulin
- ANCA
- CRP
- SPEP/UPEP
- Imaging of kidneys
What imaging of the kidneys is done to assess the cause of CKD?
- Ultrasound
- CT
- MRI
Why is ultrasound done in the assessment of CKD?
Looking at size and hydronephrosis
What steps are taken in the conservative management of CKD?
- To prevent or delay progression, there are several potentially modifiable risks
- The patient should be monitored
What risks are potentially modified in the conservative management of CKD?
- Lifestyle
- Treat diabetes (if present)
- Treat blood pressure (if high)
- ACE inhibitors / angiotensin receptor blockers
- Lipid lowers
What lifestyle changes can be made in CKD?
- Smoking
- Obesity
- Exercise
What lipid lowers are used in the conservative management of CKD?
- Diet
- Statins
How should the patient be monitored in the conservative treatment for CKD?
- Checking their eGFR
- Indiciations for initiation of dialysis
When is renal replacement therapy required?
When native renal function declines to a level when it is no longer adequate to support health
What renal function is deemed to be no longer adequate to support health?
When GFR <10ml/min
What is renal replacement therapy?
Either dialysis or renal transplantation
What are the indications for dialysis?
- Uraemic symptoms
- Acidosis
- Pericarditis
- Fluid overload
- Hyperkalaemia
What are the types of dialysis?
- Haemodialysis
- Peritoneal dialysis
What does haemodialysis require?
The creation of a arteriovenous (AV) fistula
What is an arteriovenous fistula?
A connection between an artery and a vein
What vessels is the arteriovenous fistula made between in haemodialysis?
- Cephalic vein
- Radial artery
What is the purpose of the arteriovenous fistula in haemodialysis?
Provides vascular access
Why does an arterioenous fistula provide vascular access?
The difference in pressure means that blood moves from the artery to the vein, causing it to dilate and develop a muscular wall
What happens in haemodialysis?
The patient is connected up to dialysis machine, which allows for filtering of patients blood
What does a dialysis machine contain to allow for filtering of the patients blood?
Highly purified water across a semi-permeable membrane
What drugs need to be given in haemodialysis?
Anti-coagulants
Why are anti-coagulants needed in haemodialysis?
To prevent the patients blood from clotting in the machine
What are the advantages of haemodialysis over peritoneal dialysis?
- Effective
- 4/7 days free from treatment
- Dialysis dose easily prescribed
How long can people survive on haemodialysis?
>25 years
What are the disadvantages of haemodialysis over peritoneal dialysis?
- Fluid/diet restrictions
- Limits holidays
- Access problems
- CVS instability
- High capital cost
What does peritoneal dialysis require?
- The peritoneal membrane
- Blood flow
- Peritoneal dialysis fluid
What happens in peritoneal dialysis?
Peritoneal dialysis fluid is put into the peritoneal cavity, and the dialysis occurs across the peritoneal membrane (semi-permeable membrane). The fluid is then drained away and disposed of
What are the advantages of peritoneal dialysis over haemodialysis?
- Low technology
- Home technique
- Easily learned
- Allows mobility
- CVS stability
Who is peritoneal dialysis better for?
Elderly and diabetics
What are the disadvantages of peritoneal dialysis over haemodialysis?
- Frequent exchanges (~4/day)
- No long term survivors yet
- Frequent treatment failures
- Peritonitis
- Limited dialysis dose range
- High revenue costs
Who should be considered for renal transplantation?
All patients with progressive CKD or end-stage renal failure
What are the sources of kidneys for transplantation?
- Cadaver donors
- Non-heart beating donors
- Living related donors/friends
- Autristic donors
What location is a kidney transplanted too?
Not the normal anatomical location, but the iliac fossa
Why is a kidney transplanted to the iliac fossa?
Because it can be easily connected to the iliac vessels and the bladder
What are the advantages of renal transplantation?
- Restores near normal renal function
- Allows mobility and ‘rehabilitation’
- Improved survival
- Good long term results
- Cheaper than dialysis
What are the disadvantages of renal transplantation?
- Not all are suitable
- Limited donor supply
- Operative morbidity and mortality
- Life long immunosuppression
- Still left with progressive CKD