Exam 2: Renal acid / base regulation and disorders II

Question 1

Metabolic Acidosis

Answer 1

• Overproduction or ingestion of acids or loss of base
• Decreased HCO₃^- causes decrease in blood pH (acidemia)
• Acidemia causes hyperventilation which is the respiratory compensation for metabolic acidosis
• Correction of metabolic acidosis
  
  • Increase excretion of excess H+
  • Generation of “new” HCO₃^-

Question 2

Metabolic Alkalosis

Answer 2

• Loss of H+ or gain of HCO3-
• Increased HCO₃^- increases blood pH
• Alkalemia causes hypoventilation as respiratory compensation
• Correction of metabolic alkalosis
  
  • Increased excretion of HCO₃^-

Question 3

šTime for compensatory response

Answer 3

6-12 hours for respiratory compensation

vs.

3-5 days for metabolic compensations

Question 4

šExplain lab values for respiratory acid-base disorders and metabolic acid-base disorders in detail

Answer 4

Question 5

šDescribe some conditions that result in metabolic and respiratory acid-base disorders:

Diarrhea

Answer 5

• Diarrhea
  
  • Results in the loss of HCO₃^- into the feces
  • Metabolic acidosis

Question 6

šDescribe some conditions that result in metabolic and respiratory acid-base disorders:

Vomiting

Answer 6

• Vomiting
  
  • Loss of acid
  • Metabolic Alkalosis
  • If the vomiting is large amounts from deeper in the GI tract
    
    • Cause loss of bicarbonate resulting in metabolic acidosis

Question 7

šDescribe some conditions that result in metabolic and respiratory acid-base disorders:

Diabetes Mellitus

Answer 7

• Diabetes Mellitus
  
  • Lack of insulin secretion
  • Blood acetoacetate acid levels can rise
  • Severe metabolic acidosis
  • To compensate for the acidosis large amounts of acid are excreted in the urine

Question 8

šDescribe some conditions that result in metabolic and respiratory acid-base disorders:

Chronic renal failure

Answer 8

• Chronic renal failure
  
  • Metabolic acidosis
  • Build up of weak acids
    
    • that cant be excreted
  • Decreased glomerular filtration rate
    
    • which reduces the excretion of phosphates and NH₄⁺
  • Reduction in HCO₃^- reabsorbed