Acute Renal Failure

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Acute Renal Failure
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3 Categories of Renal Failure

• Pre-Renal
• Condition that causes a decrease in blood flow to
  the kidneys
• Reduced HP at glomeruli results in poor
  filtration
• Post-Renal
• An obstruction in the outflow of urine
• Increase HP in Bowmans capsule results in poor
  filtration
• Intra-Renal
• Direct damage to kidneys, esp. glomeruli
• Less effective surface area results in poor
  filtration

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Match the Causes

• Post-Renal
• Pre-Renal
• Intra Renal

• Myocardial Infarction
• Ureteral Stone
• Streptococcus pharyngitis

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Post-Renal Ureteral Stone

• The material that makes up the stones often
  consists of calcium deposits, among other things
• These can cause blockage of urine flow
• Urine backs up into the kidneys causing nephrons
  to shut down due to an increase in pressure

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Analogy

• In this analogy the ureter acts as a stream
• Beavers come and build a dam (ureter stones) that
  block the passage of water down the stream
• The dam causes a backflow of water that damages
  the surrounding habitat (kidneys)

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Pre-Renal Myocardial Infarction

• The heart weakens and cannot pump sufficient
  amounts of blood to the kidneys
• Glomerular filtration rate decreases (kidney
  failure ensues)
• The kidneys may compensate by retaining more salt
  and water to increase blood volume

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Analogy

• In this analogy blood is represented by water
• A drought occurs (myocardial infarction)
• Kidneys act as a dam conserving water (blood),
  which supplies the people with enough water to
  survive (i.e. blood supplying tissues)

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Intra-Renal Glomerulonephritis

• A Streptococcus bacterial infection of the throat
  or skin can lead to acute post-streptococcal
  glomerulonephritis
• Strep antigens and antibodies form complexes that
  attach to the glomerulus
• The inflammation impairs the kidneys ability to
  filter and eliminate waste causing low output of
  urine

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Analogy

• In this analogy a river represents the kidneys
• An oil spill represents Acute post-strep
  glomerulonephritis
• The river cannot filter out or diffuse all the
  sticky oil
• Therefore the oil ends up disturbing natural
  habitat around the river and it cannot function
  properly

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Questions???

• Anyone? Anyone?