Flashcards in Session 11 - Chronic Kidney Disease Deck (60):
Define chronic kidney failure
• The progressive and irreversible loss of renal function over a period of months to years
What is the underlying pathology of chronic kidney failure?
• Function renal tissue is replaced by extra-cellular matrix, which gives rise to glomerulosclerosis and tubular intersitial fibrosis
What does a diseased kidney do?
What does chronic kidney failure result in?
• Progressive loss of both the excretory and hormone functions of the kidney
• Proteinuria and systemic hypertension develops
Give 8 causes of chronic kidney disease
I gave GOD HIV
○ Polycystic Kidney Disease (PCK)
○ Alport’s Syndrome
• Obstruction and reflux nephropathy
• Systemic Disease
• Cause unknown
What are the three most common causes of chronic kidney disease
• Diabetes mellitus
What do most patients with CKD have?
• Ischaemic Heart Disease
What is polycystic kidney disease?
• Multiple cysts appear on the kidney
What is Alport syndrome?
• Hereditary nephritis caused by an x-linked mutation
• Proliferating and sclerosing kidney disease
How is Chronic Kidney Disease classified?
• By amount of GFR fall and kidney disease
How many stages of chronic kidney disease are there?
What is stage 1 of chronic kidney disease? GFR, description, clinical diagnosis, %population
• >90 GFR
• Kidney damage with normal or increased GFR
• Need other evidence of kidney damage
What is stage 2 of chronic kidney disease? GFR, description, clinical diagnosis, %population
• 60-89% GFR
• Kidney damage with mild GFR fall
• Need other evidence of kidney dmage
• 3% population
What is stage 3 of chronic kidney disease? GFR, description, clinical diagnosis, %population
• 30-59% fall in GFR
• Moderate fall in GFR
• Symptoms +/-
What is stage 4 kidney disease?
• Severe fall in GFR
• Symptoms ++
• 0.2% population
What is stage 5 kidney disease
• <10ml/min GFR
• 0.1% population
What is the incidence of CKD?
• 85% have diabetes, hypertension or ischaemic heart disease
• More common in the elderly, ethnic minorities and the socially disadvantaged
Why don't most patients with CKD end up needing dialysis?
High cardiovascular mortality at all stages of CKD
Give four systems affected by CKF
What does CKF cause in the CVS system?
What does CKF cause in haemotologically
○ Decreased erythropoietin
○ Resistance to erythropoietin
○ Decreased RBC survival
Where is erythropoietin produced?
The interstitial fibroblasts in the kidney, in close assocaiation with peritublar capillaries.
What does CKF cause in the bone?
• Renal bone disease
Give two forms of renal bone disease
• Decreased GFR means less phosphate is excreted, increasing serum conc. Then forms complexes with free Ca2+, reducing effective serum conc. Stimulated PTH release, causing overactivity of osteoclasts - Osteitis Fibrosa Cystica
• Less Vitamin D hydroxylated to Calcitriol, causing hyperparathyroidism and osteomalacia
Where does hydroxylation of vitamin D occur?
• First step in the liver - prohormone calcifedol
Second step in the kidney
Give three CNS symptoms of CKD
Give three general symptoms of CKD?
How likely is a patient to require dialysis compared to their changes of having a CVS event?
• More likely to have CVS event than to require dialysis
What is a normal range of GFR?
• 80-120 ml/min
How can you compare current GFR of patient to normal GFR?
• % of normal GFR
• Use inulin clearance of 24hr creatinine clearance
What is inulin clearance?
• Extract inulin
• Infuse inulin into patient until steady plasma state
• Measure it's presence in the urine over a given rate
What is 51Cr EDTA?
• Measure radioactivity
What is creatinine clearance?
• Patient collects urine over 24hrs
• Delivered to lab, blood sample taken
What is eGFR and what must be taken into account when finding it?
• Estimated GFR used to assess creatinine clearance
• Must take into account age, sex, gender and ethnicity
Why is creatinine clearance not a perfect marker of renal function?
• Someone with a GFR of 40% normal can still have a normal creatinine level
• Only accurate in adults and not useful in acute renal failure
What is creatinine?
• Muscles produce creatine, which is converted to creatinine in blood
• Levels determined by muscle mass and kidney function
Why is age taken into account when measuring creatinine?
• Lower muscle mass when old
Why is gender taken into account when measuring creatinine?
Females have lower muscle bulk
Why is ethnicity taken into account when measuring creatinine?
• Some ethnicitys have a higher muscle mass
Give three ways of imaging the kidney
• Ultrasound to look at size and hydronephrosis
Give three ways of assessing cause of CFK
• Autoantibody screen
• Immunoglobulin A
What does treatment of CFK aim to do?
• Delay progression
Give five modifiable risk factors of CKF
• Treat diabetes
• Blood pressure
• ACE inhibitor
When is Renal Replacement Therapy indicated?
What are the two types?
• When native renal function declines to a level where it can no longer support health
• RRT is either dialysis or renal transplantation
Give five indications for dialysis
• Uraemic symptoms
• Fluid overload
What are two types of dialysis
• Peritoneal dialysis
What is haemodialysis
• Requires the creation of an arteriovenous fistula
• Vascular access used to connect patient to dialysis machine, which contains highly purified water across a semi-permeable membrane, allowing for blood filtering
What is an arteriovenous fistulae?
- A connection between an artery and vein
• Difference in pressure means vein dilates and developes a muscular wall, which provides vascular access
Why is an AV fistula required?
• Increases strength of vein
• Increases blood flow through vein
What is used to keep blood flowing smoothly in dialysis
An anti-clotting agent
Give three advantages of haemodialysis
• Effective (survivors >25 years
• 4/7 days free from treatment
• Dialysis dose easily prescribed
Give five disadvantages of haemodialysis
• Fluid/diet restriction
• Limits holidays
• Access problems
• CVS instability
• High capital cost
What is peritoneal dialysis?
• Requires peritoneal membrane, blood flow and peritoneal dialysis fluid
• Peritoneal dialysis fluid placed in peritoneal cavity and dialysis occurs across the peritoneal membrane
• Fluid then drained away and disposed of
Give 5 advantages of peritoneal dialysis
• Low technology
• Home technique
• Easily learned
• Allows mobility
• CVS stability
Give 6 disadvantages of peritoneal dialysis
• Frequent exchanges
• No long term survivors yet
• Frequent treatment failure
• Limited dialysis dose range
• High revenue cost
Who is considered for a kidney transplant?
• All patients with progressive CKD or end-stage renal failure
Give four sources of kidney transplants
• Cadaver donors
• Non-heart beating donors
• Living related donors
• Altruistic donors
• Kids from the backstreet of Nepal you tempted into a backstreet with the promise of free money. Sarah.
Where is a kidney put when it is transplanted?
• Iliac fossa
• Allows it to be easily connected to iliac vessels and the bladder
Give five advantages of kidney transplantation
• Restores near normal renal function
• Allows mobility and rehabilitation
• Improved survival
• Good long term results
Cheaper than dialysi