Acid Base - RR

Question 1

What three variables are represented on the Davenport graph?

Answer 1

pH, bicarb, and PCO2

Question 2

What part of the Henderson-Hasselbach equation do the kidneys regulate? The lungs?

Answer 2

The kidneys regulate the amount of bicarb

The lungs regulate the PC02

Question 3

What does the ratio of HCO3- to CO2 have to be to maintain a pH of 7.4?

Answer 3

20

Question 4

What is the normal pH? HCO3-? pCO2?

Answer 4

pH: 7.35-7.45
HCO3-: 24
PCO2: 40

Question 5

If the lungs can’t expire CO2 at a rate equal to the production of CO2 in tissues, then what happens to the PCO2, pH and HCO3-

Answer 5

PCO2 increases
pH decreases
HCO3- increases

Question 6

What happens to the PCO2, HCO3- and pH in someone who is hyperventilating?

Answer 6

PCO2 decreases
HCO3- decreases
pH increases

Question 7

The Davenport graph can be split up into quadrants with each quadrant representing either metabolic acidosis/alkalosis and respiratory acidosis/alkalosis. Where are these located in the Davenport graph?

Answer 7

Upper left: respiratory acidosis
Lower left: metabolic acidosis
Upper right: metabolic alkalosis
Lower right: respiratory alkalosis

Question 8

The decrease in pH seen with respiratory acidosis is due to what?

Answer 8

A build up of CO2 due to hypoventilation

Question 9

What are some causes of hypoventilation?

Answer 9

COPD (emphysema), asthma, narcotics/anesthesia, airway obstruction, lung collapse, muscular dystrophy, pneumonia, bronchitis, severe pulm edema

Question 10

What has a more immediate response: respiratory or renal?

Answer 10

Respiratory

The renal compensation is delayed

Question 11

What are the pulmonary and renal compensation to respiratory acidosis?

Answer 11

Pulm: increase ventilation
Renal: increase reabsorption of HCO3- and increase excretion of H+

Question 12

What does the pH of blood depend on? H+, CO2, HCO3-?

Answer 12

H+

Question 13

The increase in pH seen with respiratory alkalosis is due to what?

Answer 13

Decreased PCO2 caused by hyperventilation

Question 14

What are some causes of hyperventilation?

Answer 14

Anxiety attack, ventilator is set too high, trauma to the respiratory center in the brain, brain tumor

Question 15

What are the pulmonary and renal compensations to respiratory alkalosis?

Answer 15

Pulm: decrease ventilation
Renal: decrease excretion of NH4Cl and increase bicarb excretion

Question 16

What causes metabolic alkalosis?

Answer 16

Increased bicarb
From vomiting, gastric tubes (to remove gastric juices), overdose of antacid, diuretics, hyperaldosteronism, dehydration leading to K+ deficiency

Question 17

What are the pulmonary and renal responses to metabolic alkalosis?

Answer 17

Pulm: decrease ventilation
Renal: decrease reabsorption of HCO3-

Question 18

What causes metabolic acidosis?

Answer 18

Decreased bicarb

1. Excessive overproduction of endogenous acid or excessive exogenous acid– like in DM, starvation, or poisons
2. Under excretion of acid by the kidney
3. Excessive renal excretion of bicarb
4. GI loss of bicarb (diarrhea)

Question 19

What is the anion gap?

Answer 19

Anion gap= Sodium- (chlorine + bicarb)

Question 20

What are the causes of anion gap metabolic acidosis? Does the anion gap increase or decrease?

Answer 20

Causes: DM, lactic acid, poisons

Anion gap is increased

Question 21

What are the causes of non-anion gap metabolic acidosis?

Answer 21

Severe diarrhea and uremias (proximal renal tubular acidosis where have decreased reabsorption of bicarb and distal renal tubular acidosis where have decreased secretion and excretion of H+)

Question 22

What are the pulmonary and renal compensations for metabolic acidosis?

Answer 22

Pulm: hyperventilation
Renal: increased reabsorption of bicarb

Question 23

What is the equation for base excess? What does this tell us?

Answer 23

Base excess= Actual [HCO3-]- 24

Tells us how bad the acid/base problem is