Renal Failure Flashcards
Role of kidneys
elimination of waste products control of fluid balance regulate acid-base balance produce hormones regulate electrolytes
GFR
rate at which blood is cleared of waste
is normally 120ml/min
-if this is reduced then there is renal impairment
Acute kidney injury vs chronic kidney disease
Acute - hours to days, potentially reversible
Chronic - weeks, months, years - progressive, irreversible
How to assess acute kidney injury
- look at serum creatinine and urine output
- then can stage this
Risk factors for people to develop acute kidney injury
acute illness examples that can cause this?
- CKD
- age > 75 years
- DM
- CHF
- liver failure
- drugs - non steroidal, getnamicin, ace inhibitors
- past history of AKI
or if you have acute illness - hypotension, sepsis, hypovolaemia, high EWS
How to manage this ?
- Identify patient at high risk
- assess and optimise volume status
- stop all nephrotoxic agents
- review medications - dose adjust
- monitor creatinine and urine output
- diagnostic workout - relevant symptoms
- invasive diagnostic workout
- daily weights - to see fluid status
- diet
- targeted therapy
Chronic Kidney disease
An abnormality of kidney structure or function present for more than 3 months with implications for health
-is classified based on cause, GFR, albuminuria
How to calculate GFR
- clearance of artificially injected substances
- creatinine clearance
Inulin is filtered by the glomerulus and is not reabsorbed or secreted into the tubule.The gold standard is to inject insulin into the blood, and then measure teh clearance in urine
Isotype clearance - radioactive substance hten measure level in blood and secretion - very secerte - do this if peopel want to donate kidney to see if its good
Also look at creatinine - is free filtered form the glomerulus, however this reflects body size and mass
-need to standardise it
-as kidney declines more, get more creatinine clearance - results in an overestimation of GFR in patients near end-stage renal disease
risk greater if have albuminuria and low GFR - increase risk of dying and cardiovascular death
Most common causes of chronic kidney disease
- diabetic nephropathy
- glomerulonephritis
- hypertensive nephrosclerosis
- polycystic kidney disease
How to manage
If you do not control this it will lead to end stage CKD
-need to sort out the primary disease
Secondary factors that can be caused
- systemic hypertension
- intraglomerular hypertension
- glomerular hypertrophy
- calcium and phosphate
- dyslipidaemia
- proteinuria
- tubulo-interstitial fibrosis
- toxcitiy of iron/ammonia, middle moleucles
-need to treat to slow the progression of the kidney disease
Hypertension
big cause
- need to be controlled
- renal survival is increased when there is lower blood pressure
- can do this by weight loss, salt restriction, exercise, moderation of alcohol, stop smoking
- diuretics
- renein-angiotensin antagonists
- SNS reduction
-will need drugs to improve hypertension
Proteinuria
- important prognostic factor
- reduction in proteinuria can improve outcome
- can do this by weight loss, ACE-1, aldoesterone antagonists, statins
- lower BP
- sometimes protein restrict
Calcium and phsophate
with stage 3 renal disease, can get an increase in calcium and phosphate content
- this is associated with progressive renal impariment and decline in renal funciton
- imrpovement of Ca/P can mean that there is a reduction in the rate of decline
- can limit phosphate in the diet e.g calcium carbonate,
Water status
-dont wnat volume overload
