clinical assessment of respiratory disease

Question 1

how to calculate respiratory quotient (respiratory exchange ratio)

Answer 1

CO2 production/oxygen consumption

Question 2

what is the respiratory quotient usually equal to

Answer 2

1

Question 3

how much O2 does the body consume (ml/min/kg) when sitting at rest, and what is the metabolic equivalent

Answer 3

3.5 ml/min/kg, with a metabolic equivalent of 1

Question 4

what are the metabolic equivalents of O2 consumption when standing, walking and running

Answer 4

1.5, 2, >7

Question 5

what are 2 forms of stored energy in muscles to generate muscular contraction

Answer 5

ATP, creatine phosphate

Question 6

what drives oxidative phosphorylation in muscles

Answer 6

inorganic phosphates, ADP, creatine

Question 7

what 2 processes increase during exercise in muscles

Answer 7

TCA, glycolysis

Question 8

effect on O2 consumption and CO2 production in muscles during exercise

Answer 8

oxygen consumption increases; initially CO2 production rises slowly as buffered, but then rises to match O2

Question 9

what happens to cardiac output, heart rate and oxygen consumption in the circulatory response to exercise

Answer 9

increases linerarly with intensity until plateaus as maximum reached

Question 10

what happens when heart rate is too fast in the circulatory response to exercise

Answer 10

filling time in diastole is reduced, reducing stroke volume after a peak

Question 11

what happens to tidal volume and ventilaton in the lung response to exercise

Answer 11

increases up to a peak where it plateaus, with breathing frequency increasing

Question 12

what is the most efficient fraction of vital capacity to breathe when exercising

Answer 12

1/2

Question 13

effect of exercise on ventilation perfusing matching

Answer 13

increases

Question 14

during incremental aerobic metabolism, what happens to oxygen flow, total body respiratory quotient and ventilation

Answer 14

oxygen flow matches demand, total body respiratory quotient rises, ventilation increases to match CO2 production

Question 15

during incremental aerobic metabolism, why does the respiratory quotient rise to 1

Answer 15

glucose becomes predominant fuel source

Question 16

describe the Bohr effect (including oxygen-dissociation curve)

Answer 16

as pH increases, Bohr shift of oxygen-dissociation curve to right, as at given PO2, Hb has less affinity to oxygen so offloads more to acidotic muscles

Question 17

what happens to lactate in acidosis

Answer 17

converted to protons

Question 18

how is the production of protons in acidosis buffered and what is the outcome

Answer 18

buffered by bicarbonate to increase CO2

Question 19

what is the outcome of the CO2 produced and effect on blood pH

Answer 19

increased ventilation of CO2 out, so pH remains relatively stable

Question 20

what happens if [H+] exceeds [HCO3-]

Answer 20

cannot buffer, so begin to hyperventilate to remove CO2 and reduce lactate

Question 21

describe cardiopulmonary exercise testing

Answer 21

patient on a bike has continuous ECG and gas exchange monitoring; power is slowly increased to put cardiopulmonary strain on the patient

Question 22

what can cardiopulmonary exercise testing be used for

Answer 22

detection of heart/lung conditions/restrictions on exercise