Flashcards in Session 10 - Acute Kidney Injury Deck (59)
What is Oliguria?
• Little urine
• Less than 500ml of urine/day or less than 20ml/hour
What is anuria?
• No urine
• Less than 100ml of urine/day
• Indicates blockage of urine flow
Give three causes of acute kidney injury
• Pre-renal disease
○ Decreased perfusion
• Post-renal failure
• Intrinsic Renal Failure
○ Dame to kidney
What is pre-renal acute kidney injury caused by?
• A reduction in renal perfusion
• If not treated promptly acute tublar necrosis will develop
Give two over arching causes of pre-renal AKI
• Reduced effect ECF volume
Impaired renal autoregulation
Give three overarching causes of reduced effective ECF volume
• Systemic vasodilation
• Cardiac failue
Give two causes of hypovolaemia
• Blood loss
• Fluid loss
Give three causes of systemic vasodilation
Give three causes of cardiac failure
• LV dysfunction
• Valve disease
Give two causes of impaired renal autoregulation
• Preglomerular vasoconstriction
• Postglomerular vasodilation
Give four causes of preglomerular vasoconstriction
• Hepatorenal syndrome
• Drugs - NSAIDS
Give two causes of post glomerular vasodilation
• ACE inhibitors
• Angiotensin 2 antagonists
What is post renal AKI?
• Injury as a result urine flow obstruction
What are the three sites at which urine flow can be blocked, causing post renal AKI?
What are three places obstructions can be at each particular site in post renal AKI?
• Within the lumen
• Within the wall
• Pressure from outside
Give four causes of blockage within the wall of the ureter, bladder or urethra
• Blood clot
• Papillary necrosis
• Tumour of renal pelvis, ureter or bladder
How large must a calculi be to stop it passing?
Give two causes of obstruction within the wall of the ureter, bladder or urethra
• Ureteric stricture
What does obstruction with the wall of the ureter, bladder or urethra usually cause other than acute post renal AKI?
Chronic kidney injury
Give three congenital causes of obstruction within the wall of the ureter, bladder or urethra
• Pelviureterteric neuromuscular dysfunction
• Neurogenic bladder
Give five causes of pressure from outside causng post-renal AKI
• Prostatic hypertrophy
• Aortic aneurysm
• Accidental ligation of ureter
Give three causes of intrinsic AKI
• Acute tubular necrosis
• Glomerular and arteriolar disease
• Acute tubule-interstitial
What are the two main causes of acute tubular necrosis?
• Severe acute ischaemia
• Toxic acute tubular necrosis
What is severe acute ischaemia caused by?
• Pre-renal fall in perfusion, causing tubular necrosis
What is toxic acute tubular necrosis?
• Nephrotoxins damage the epithelial cells lining the tubules and cause cell death
• Nephrotoxins can be endogenous or exogenous
What is the most common cause of acute tubular necrosis?
• Where there is toxic acute tubular necrosis AND severe acute iscaemia
Name three endogenous nephrotoxins
Give four exogenous causes of ATN
• X-ray contrast
• Other poisons
Give three main drugs which are exogenous nephrotoxins
• ACE inhibitors