Ventilatory resposne to exercise

Question 1

What is the purpose of pulmonary response to exercise is to meet the increased need for?

Answer 1

atmospheric to alveolar and alveolar to pulmonary capillary gas exchange

Question 2

What is the normal exercise response?

Answer 2

exercise has minimal effect on valves for alveolar O2 and CO2

Question 3

What is the role of exercise on blood gas and pH?

Answer 3

effect of exercise on arterial blood gases in humans s characterizzed by homeostasis until about 60% of max metabolic rate

homeostasis indicates signal for hyperpnea during exercise cannot be increased stim of carotid and intracranial chemoreceptors

during exercise abvoe about 60% max capacity increased lactic acid prouction decreased arterial pH

note hyperventilation at high work rates whichc doesn’t increase PaO2

HR is used as an index of work intensity

Question 4

What is the role of alveolar to capillary gas exchange during exercise?

Answer 4

increase in alveolar to capillary gas exchange is indicated by increase in DLco

Question 5

How does DLCO increase in exercise?

Answer 5

recruitment of alveolar-capillary units which increases surface areaa for gas exchange

Question 6

Increase in A-a PO2 differences at high workloads reflect what?

Answer 6

hyperventilation increasing PAO2 which increases the alveolar to capillary driving rpessure and maintains normal PaO2 even though diffusing capacity at high workloads has not increased in poportion to increase in work rate

Question 7

What is the temporal pattern of ventilation during exercise?

Answer 7

temporal pattern suggests fast and slow component

fast component is postulated to reflect a command from hypothalamic motor areas (central command)

slow component might be due to feedback from muscles

Question 8

What is respiratory quotient?

Answer 8

CO2elimiinated/O2consumed;

at tissue level

values correspond to a caloric value for each liter of CO2 produced. IF O2 consumption numbers are available they are usually used directly since they are more reliable measures

Question 9

What is respiratory exchange rate?

Answer 9

ratio between amount of CO2 produced/O2 consumed in one breath

measurement of RQ at atmospheric level

Question 10

What is the normal respiratory exchange rate?

Answer 10

breathe in one more molecule and breath out one mole ocule of carbond dioxide

Question 11

What is anaerobic threshold?

Answer 11

exercise intensity at which lactate starts to accumulate in blood stream about 60% of max metabolic rate

Question 12

What is lactic acid a marker of?

Answer 12

anaerobic metabolism,

Question 13

What is the pH of exercising muscle?

Answer 13

7.00

Question 14

What is very light exercise?

Answer 14

borg scale 6-9
45-55% of VO2max or HR reserve
60-70% HRmax
BL<2mmol/l

Question 15

What is cardiopulmonary exercise testing?

Answer 15

progressive workload test
pt exercises to exhaustion and/or until symptoms are reproduced
CPET assesses the integrated physiology of cardiac respiratory system : what is limiting exercise in this pt? is it the herat or lungs?

Question 16

What are the indications for CPET?

Answer 16

most commonly for evaluation of unexplained dyspnea
undiagnosed exercise intolerance
suitability for heart and or lung transplant
pre-op evaluation
disability detrmination
prognostication in heart failure

Question 17

What are the exercise limitations?

Answer 17

cardiac
pulmonary
muscular
deconditioning
obesity
poor effort/motivation