ACID BASE PRINCIPLES

Question 1

What is the primary site of bicarbonate reabsorption in the nephron?

Answer 1

Proximal tubule

Responsible for 80% of bicarbonate reabsorption

Question 2

What condition is characterized by impaired bicarbonate reabsorption in the proximal tubule?

Answer 2

Proximal renal tubular acidosis

Often associated with Fanconi’s syndrome

Question 3

What is the main consequence of bicarbonate loss in proximal renal tubular acidosis?

Answer 3

Non-anion gap metabolic acidosis

Question 4

What syndrome is a reabsorptive defect in the thick ascending limb of the nephron?

Answer 4

Bartter syndrome

Question 5

What causes increased serum bicarbonate levels in Bartter syndrome?

Answer 5

Increased proximal tubular reabsorption secondary to hypovolemia

Question 6

What is the reabsorptive defect in Gitelman syndrome?

Answer 6

Distal tubule reabsorption of sodium chloride

Question 7

What is the typical urinary buffer that absorbs protons?

Answer 7

Titratable acids

Question 8

What is ammoniagenesis?

Answer 8

Conversion of glutamine into ammonia and alpha-ketoglutarate

Question 9

What does net acid excretion (NAE) measure?

Answer 9

Amount of acid excreted in the urine per time

Question 10

How is NAE calculated?

Answer 10

Ammonium + titratable acids - bicarbonate

Question 11

What indicates a significant uncompensated acidosis in a patient?

Answer 11

A pH of 7.25

Question 12

What is the expected renal compensation in chronic hypoventilation?

Answer 12

Increased serum bicarbonate

Question 13

What condition is indicated by an anion-gap metabolic acidosis with abdominal pain and hyperglycemia?

Answer 13

Diabetic ketoacidosis (DKA)

Question 14

What is Kussmaul breathing?

Answer 14

Deep and labored breathing as a compensatory mechanism for acidemia

Question 15

What is the formula for calculating the anion gap?

Answer 15

Anion Gap = Na+ - (Cl− + HCO3−)

Question 16

What indicates mixed metabolic and respiratory acidosis?

Answer 16

Low bicarbonate and elevated carbon dioxide levels

Question 17

What is lactic acidosis?

Answer 17

A condition where lactic acid accumulates due to anaerobic metabolism

Question 18

What is the primary buffer used to neutralize lactic acid?

Answer 18

Bicarbonate (HCO3−)

Question 19

What is the consequence of severe alkalemia on calcium levels?

Answer 19

Hypocalcemia

Question 20

What is the relationship between shock and lactic acidosis?

Answer 20

Shock causes underperfusion of tissues, leading to anaerobic metabolism and lactic acid production

Question 21

What is the effect of metabolic acidosis on respiratory rate?

Answer 21

Causes hyperventilation

Question 22

What condition is associated with progressive muscle weakness and respiratory failure?

Answer 22

Amyotrophic lateral sclerosis (ALS)

Question 23

What leads to respiratory acidosis in ALS patients?

Answer 23

Alveolar hypoventilation causing CO2 retention

Question 24

What is Winter’s formula used for?

Answer 24

To confirm respiratory compensation for metabolic acidosis

Question 25

What indicates that a patient is blowing off too much carbon dioxide?

Answer 25

pCO2 below the expected range according to Winter's formula