Acid and base 2

Question 1

What is normal range of:
pH, HCO3-, PCO2 (units)

Answer 1

·pH- 7.35-4.45
·HCO3- 24-25 mM
·PCO2- 40 mmHg

Question 2

What is the equation for formation H+ ions?

Answer 2

Question 3

If high/low pH what is patient suffering from?

Answer 3

Alkalosis- higher pH
Acidosis- lower pH

Question 4

What changes in equation indicate respiratory issues

Answer 4

Changes in PCO2
H2O shifting equlibrium

Question 5

What changes in equation indicate metabolic issues?

Answer 5

Changes in H+
HCO3- shifting equilibrium

Question 6

What does direction of shift represent?

Answer 6

Represents acidosis/alkalosis

Question 7

If respiratory which axis should follow?

Answer 7

Respiratory- Hb buffer to new pCO2 lvl
Metabolic- PCO2 to HCO3-

Question 8

How is respiratory compensated?

Answer 8

Airway dysfunction- can’t change PCO2
- kidneys comp

Question 9

How is metabolic compensated?

Answer 9

Respiratory system compensates

Question 10

look

Answer 10

Question 11

Draw davenport diagram?
Resp acidosis
Normal
Resp alkalosis

Answer 11

Question 12

Draw davenport diagram?

Answer 12

Met acidosis
Normal
Metabolic alkolosis

Question 13

How are changes in pH compensated?

Answer 13

Base excess- increase/decrease in base counteract rise in acid

Question 14

What is partial and full compensation?

Answer 14

Partial- pH not returned normal
Fully- pH normal
If no base excess- complex acid/base disturb.

Question 15

What are causes metabolic acidosis? Define?

Answer 15

Causes- creation, ingestion, retention of acids
·Renal failure
·GI- HCO3- loss e.g. cholera
·Dilution of blood; more H20 in blood, more acidic it gets (H20 dissociates into H+ and OH-)
·Failure of H+ excretion- hypoaldosteronism, - Less Na+ reabsorbed on the Na/H counter-
transporter- less H+ secreted
- Diabetic ketoacidosis- high production ketone
bodies

Question 16

What is metabolic acidosis?

Answer 16

Increase in acid production or loss of buffering - Result in decreased pH

Question 17

What is the compensation for metabolic acidosis?

Answer 17

Respiratory compensation
·Stimulate chemoreceptors, enhance
respiration, results in falling PCO2
·Increases the pH to return to normal

Question 18

What are causes respiratory alkalosis?

Answer 18

Causes; CO2 depletion due to hyperventilation
·Hypoxia
·Type 1 respiratory failure (e.g. pulmonary embolism, decreased O2 and decrease/no change in CO2)

Question 19

What are signs of type 1 resp failure?

Answer 19

Pulmonary embolism
Decreased O2
Decrease/no change in CO2

Question 20

Explain respiratory alkalosis? pH?

Answer 20

Too much CO2 loss
40 to 27 mmHg
Increase in pH

Question 21

What is compensation for respiratory alkalosis?

Answer 21

Renal compensation;
·Kidneys decrease H+ secretion by retaining H+
·This results in decreased HCO3– reabsorption
in the proximal tubules and collecting ducts
(more excreted)
·Less buffering capacity, low base excess
·pH rises

Question 22

Explain metabolic alkalosis? pH?

Answer 22

Results in increased [HCO3-] and buffering capacity
- Rise in pH

Question 23

What is the compensation for metabolic alkalosis?

Answer 23

Respiratory compensation
·Inhibition chemoreceptors- reduces
respiration rate
·Increases PCO2
·This decreases the pH

Question 24

Causes of respiratory acidosis?

Answer 24

Causes; CO2 retention
·Hyperventilation
·COPD
·Respiratory failure; type 1 = pulmonary embolism, type 2 = hypoventilation

Question 25

What causes type 1 resp failure?

Answer 25

Pulmonary embolism

Question 26

What causes type 2 resp failure?

Answer 26

Hypoventilation

Question 27

Explain respiratory acidosis? pH?

Answer 27

Increase pCO2- 40-60 mmHg
pH falls

Question 28

What is compensation for respiratory acidosis?

Answer 28

Renal compensation;
·Increase HCO3– (high base excess) release into plasma- buffer H+ created by the increased PCO2
Acute phase = CO2 moving into erythrocytes combines with H2O (and carbonic anhydrase) to produce HCO3-.
Chronic response- increase HCO3– reabsorption by the kidneys, better for the stabilisation of pH
·Excrete more H+ in the form of ammonia (NH3+ to NH4)