Acute Renal Failure Flashcards
Definition of acute renal failure
Sudden reduction in renal function
Types of acute renal failure
Pre-renal (most common in children)
Renal
Post-renal
Acute on chronic
Causes of pre-renal renal failure
Hypovolaemia e.g. gastroenteritis, burns, sepsis, haemorrhage, nephrotic syndrome
Circulatory failure
Vascular causes of renal failure
Haemolytic uraemic syndrome
Vasculitis
Embolus
Renal vein thrombosis
Tubular causes of renal failure
Acute tubular necrosis
Ischaemic
Toxic
Obstructive
Glomerular and interstitial causes of renal failure
Glomerular: glomeruloneprhitis
Interstitial: interstitial nephritis, pyelonephritis
Causes of post-renal failure
Obstruction:
Congenital e.g. posterior urethral valves
Acquired e.g. blocked urinary catheter
Clinical features of acute renal failure
Oliguria
Investigations in acute renal failure
Renal biopsy if cause unclear
General management of acute renal failure
Circulation and fluid balance monitoring
USKUB
What might USKUB identify in acute renal failure?
Obstruction
Small kidneys in chronic disease
Large, bright kidneys with loss of cortico-medullary differentiation in acute processes
Management of pre-renal failure
Hypovolaemia
Urgent correction with fluid replacement
Circulatory support to prefer acute tubular injury & necrosis
Management of (renal) renal failure
Restrict fluid intake
Diuretic challenge if circulatory overload
High calorie, normal protein diet
Manage catabolic derangements
Renal biopsy to rule out rapidly progressive GN
Why is a normal calorie, high protein diet used in renal failure?
Decrease catabolism, uraemia and hyperkalaemia
Management of post-renal failure
Assess site of obstruction
Relief by nephrostomy or catheterisation
Surgery when fluid volume and electrolytes corrected
