Acid-Base Balance II

Question 1

What is compensation?

Answer 1

the restoration of pH regardless of what happens to HCO3 or PCO2

Question 2

What is correction?

Answer 2

restoration of pH and HCO3 and PCO2 to normal

Question 3

What are the types of disturbances to A-B balance?

Answer 3

respiratory origin

non-respiratory origin

Question 4

What are the blood buffers?

Answer 4

HCO3 and Hb

Question 5

What are the ECF buffers?

Answer 5

HCO3

Question 6

What has to rectify store depletion?

Answer 6

kidney

Question 7

What can be analysed by blood gas?

Answer 7

CO2 and pH

Question 8

What is plotted on the Davenport diagram?

Answer 8

HCO3 - y axis

Plasma pH = x axis

Question 9

What is respiratory acidosis?

Answer 9

retention of CO2 by body

Question 10

What can cause respiratory acidosis?

Answer 10

chronic bronchitis
chronic emphysema
airway restriction
chest injuries

Question 11

What indicates uncompensated respiratory acidosis?

Answer 11

pH less than 7.35 due to increase H ion and PCO2 > 45mmHg

Question 12

How is respiratory acidosis compensated for?

Answer 12

kidney increases H secretion and HCO3 reabsorption, generates titratable acids and NH4

Question 13

How is respiratory acidoses corrected?

Answer 13

lowering of PCO2 by restoration of normal ventilation

Question 14

What is respiratory alkalosis?

Answer 14

excessive removal of CO2 by body

Question 15

What can cause resp. alkalosis?

Answer 15

low inspired PO2 at altitude causes ventilation
hyperventilation - fever and brainstem damage
hysterical over breathing

Question 16

What indicates uncompensated respiratory alkalosis?

Answer 16

pH >7.45 and pCO2 less than 35mmHg

Question 17

How is resp. alkalosis compensated for?

Answer 17

reduced H secretion
HCO3 is excreted
no new HCO3 is formed

Question 18

How is resp. alkalosis corrected?

Answer 18

restoration of normal ventilation

Question 19

What is metabolic acidosis?

Answer 19

excess H from any source other than CO2

Question 20

What can cause metabolic acidosis?

Answer 20

ingestion of acids or acid producing food stuff
excessive production of H
excessive loss of base

Question 21

What happens during metabolic acidosis?

Answer 21

HCO3 is depleted as a result of buffering of H or loss from body

Question 22

What indicates uncompensated metabolic acidosis?

Answer 22

pH less than 7.35 and low HCO3

Question 23

How does the respiratory system compensate for metabolic acidosis?

Answer 23

decrease in pH stimulates peripheral chemoreceptors
increase ventilation so more CO2 removed
H is lowered and HCO3 is also lowered

Question 24

How is metabolic acidosis corrected?

Answer 24

lower filtered HCO3 and reabsorb it
H secretion continues and produces TA and NH4 to make new HCO3
acid load is excreted and HCO3 restored
ventilation is normalised

Question 25

Why is respiratory compensation essential?

Answer 25

acid load cannot be excreted immediately

Question 26

What is metabolic alkalosis?

Answer 26

excessive loss of H from the body

Question 27

What can cause metabolic alkalosis?

Answer 27

loss of HCl from stomach - vomiting
ingestion of alkali or alkali producing foods
aldosterone hyper-secretion

Question 28

What indicates uncompensated metabolic alkalosis?

Answer 28

pH > 7.45 and high HCO3

Question 29

How does the respiratory system compensate for metabolic alkalosis?

Answer 29

decreased ventilation by peripheral chemoreceptors

Question 30

How is metabolic alkalosis corrected for?

Answer 30

filtered HCO3 is not absorbed
no TA or NH4 is generated
HCO3 is excreted
HCO3 falls back to normal