111214 cardiopulm stress test

Question 1

VO2

Answer 1

oxygen consumption–amt of O2 utilized by body’s metabolic processes

Question 2

MVO2

Answer 2

maximum oxygen consumption (usually measured at peak exercise)

Question 3

lactic acid

Answer 3

marker for anaerobic metabolism

Question 4

what happens to pulm circulation during exercise?

Answer 4

pulm arterial vasodilatation–keeps PVR low

Question 5

what happens to systemic circulation during exercise?

Answer 5

vasodilatation to reduce afterload

Question 6

CO increases by how much during exercise

Answer 6

4-5x

Question 7

alveolar ventilation increases by how much during exercise

Answer 7

20

Question 8

anaerobic threshold

Answer 8

level of O2 consumption (VO2) at which the critical capillary PaO2 has been reached for a given work load

normal resting PaO2 of tissues is 100 mmHg

critical PaO2 of exercising muscle approaches 15-20 mm Hg (aerobic ceases, anaerobic metabolism begins)

important physiologic marker in exercise where homeostasis is no longer maintained

occurs at about 60% of maximal metabolic rate

is the pt at which CO2 production increases faster than O2 consumption (CO2 from lactate

Question 9

VCO2

Answer 9

CO2 production

Question 10

how can anaerobic threshold be measured?

Answer 10

invasively by drawing lactate levels in blood

noninvasively by V-slope method plotting VO2 vs VCO2

Question 11

CPET

Answer 11

cardiopulm exercise testing

progressive workload test. pt exercises to exhaustion.

Question 12

what does CPET assess

Answer 12

cardiac and respiratory system to determine what is limiting exercise in pt? is it the heart, lungs, muscles, deconditioning, obesity, poor effort?

looks at heart, lungs, muscles

Question 13

what are the indications for CPET

Answer 13

most commonly-unexplained dyspnea
undiagnosed exercise intolerance
suitability for heart or lung transplant
pre-operative eval
disability determination
prognostication in heart failure

Question 14

what is the primary limitation in healthy ppl doing the CPET?

Answer 14

cardiac (should still have leftover breathing reserve)

Question 15

how are VO2 and VCO2 measured for CPET?

Answer 15

by mouthpiece-a breath by breath plot

Question 16

how can you tell if pt did a good quality CPET?

Answer 16

look at if they reached anaerobic threshold

Question 17

what to look at on CPET

Answer 17

good effort (reached anaerobic threshold)?
have they used up breathing reserve? have they used up cardiac reserve (HR)?