B4.051 Prework 1 Acid Base Balance

Question 1

normal blood gas values

Answer 1

PaO2 95 mmHg
PaCO2 40 mmHg
pH 7.4
HCO3- 24 mM

Question 2

stimuli of alveolar ventilation

Answer 2

decreased PaO2
increased PaCO2
decreased arterial pH (increased H+ conc)

Question 3

respiratory acid base changes

Answer 3

due to a change in alveolar ventilation causing a chance in PaCO2

Question 4

metabolic acid base changes

Answer 4

change in production of loss of acid or base

Question 5

what is a metabolic compensation

Answer 5

kidneys alter excretion/absorption of H+ ions

take several days to develop

Question 6

what is a respiratory compensation

Answer 6

alter alveolar ventilation to change PaCO2 levels and production of acid from carbonic acid
occur rapidly

Question 7

what is the plasma buffer curve

Answer 7

change in pH and HCO3 when CO2 levels in plasma are altered

Question 8

buffer equation

Answer 8

CO2 + H2O <> H2CO3 <> H+ + HCO3-

Question 9

result of increased PaCO2 on buffer curve

Answer 9

increased H+ and HCO3-

shifts right

Question 10

result of decreased PaCO2 on buffer curve

Answer 10

decreased H+ and HCO3-

shifts left

Question 11

slope of plasma buffer curve

Answer 11

-10 mmol HCO3- per pH unit

Question 12

how does a change in 10 mmHg PaCO2 alter pH

Answer 12

change of 0.08

Question 13

why is the 10 mmHg/ 0.08 pH rule useful

Answer 13

helps distinguish between acute and chronic disturbances

Question 14

what is the key point of Henderson hasselbach

Answer 14

pH is proportional to ratio of bicarb/ PCO2

Question 15

what is the davenport diagram

Answer 15

HCO3- on y axis
pH on x axis
plasma buffer curve (horizontal) plotted along with PCO2 isobars (vertical)

Question 16

in reality do you see noncompensated metabolic disturbances?

Answer 16

no

respiratory compensation is almost immediate

Question 17

uncompensated resp acidosis

Answer 17

PaCO2 is increased and HCO3 is increased slightly

Question 18

compensated resp acidosis

Answer 18

PaCO2 is still increased and HCO3- is increased even more (urine will be acidic)

Question 19

uncompensated metabolic acidosis

Answer 19

PaCO2 normal and HCO3- is decreased

Question 20

compensated metabolic acidosis

Answer 20

PaCO2 decreased due to hyperventilation and HCO3- is decreased even more (due to decreased PaCO2)

Question 21

uncompensated respiratory alkalosis

Answer 21

PaCO2 decreases and HCO3- is decreased slightly

Question 22

compensated respiratory alkalosis

Answer 22

PasCO2 decreased and HCO3 is decreased even more (urine will be alkalotic)

Question 23

uncompensated metabolic alkalosis

Answer 23

PaCO2 is normal and HCO3- is increased

Question 24

compensated metabolic alkalosis

Answer 24

PaCO2 is increased due to alveolar hypoventilation and HCO3- is increased even more (due to increased PaCO2)