PRACTICAL: Cardiopulmonary Exercise Testing [CPET]

Question 1

outline the 6 steps of a pre-test procedure in CPET

Answer 1

1. calibrate equipment for gas and volume
2. ensure bike is set up for patient/participant
3. ensure there are no leaks around the edges of the mask and that it is comfortable for the patient/participant
4. ensure the patient/participant is fully aware of what the test is
5. determine the ramp setting based on patient/participants age, gender and physical activity levels.
6. aim for a test that is 8-12 mins in duration (excluding warm up and recovery)

Question 2

what are the 3 main purposes of a CPET

Answer 2

• to determine cardiorespiratory fitness
• to determine the fitness of different individuals/groups
• to determine the effect of an intervention/situation on cardiopulmonary fitness

Question 3

what are the two main physiological mechanisms assessed by a CPET?

Answer 3

• oxygen delivery by heart and lungs to skeletal muscle
• oxygen uptake and utilisation by skeletal muscles

Question 4

Define VO2 max

Answer 4

VO2 max is the maximum rate of oxygen consumption attainable during physical exertion

Question 5

what four criteria outline VO2 max

Answer 5

1. HR of ≤ 10 bpm of age predicted maximum OR HR of ≤ 5% of age predicted (220-age) maximum
2. blood lactate concentration of ≥ 8mM OR respiratory exchange ratio (RER) of >1.10
3. an RPE of 10 on a modified Borg scale (goes from 0-10, 10 being failure/maximal exertion)
4. No further increase in O2 consumption despite an increase in exercise intensity (i.e a sustained plateau in O2 consumption)

Question 6

what is VO2 peak?

Answer 6

VO2 peak is the maximum rate of oxygen consumption achieved during a CPET without the further four criterias of VO2 Max

Question 7

where is VO2 peak used more commonly than VO2 max and why?

Answer 7

• VO2 peak is used more commonly than VO2max in patient populations/those with physiological limitations.
• this is because of the relatively high intensity work needed to achieve VO2max

Question 8

define Anaerobic Threshold (AT)

Answer 8

anaerobic threshold is the level of oxygen consumption at the point where aerobic energy production needs to be supplemented by anaerobic mechanisms during incremental exercise (eg: during a CPET), causing a sustained increase in lactate and metabolic acidosis

Question 9

what are the 2 reasons why anaerobic threshold a controversial term in exercise physiology fields?

Answer 9

• Because it is incorrectly used interchangeably with lactate threshold, which happens at a significantly higher intensity than AT.
• Also used incorrectly interchangeably with ventilatory threshold, where there is VT-1 (equivalent to AT) and VT-2 (equivalent to LT)

Question 10

give 1 advantage and 1 disadvantage of using VO2max as a parameter to measure CRF

Answer 10

advantage of using VO2max:
- Gold-standard measure of cardiorespiratory fitness

disadvantage of using VO2max:
- difficult to achieve in non-athletic population

Question 11

Give 1 advantage and 1 disadvantage of using VO2peak as a parameter to measure CRF

Answer 11

advantage of VO2peak:
- achievable by everyone

Disadvantage of VO2peak:
- subjective because it is based on participant’s effort on the day defined physiological parameters

Question 12

Give 2 advantages of using AT as a parameter to measure CRF

Answer 12

two advantages of using AT:
- defined physiological threshold not impacted by participant effort

• defined thresholds established in relation to clinical challenges

Question 13

Give 2 disadvantages of using AT as a parameter to measure CRF

Answer 13

2 disadvantages of using AT:

• controversy/contention in literature as to what AT actually represents
• more complicated to determine than the other parameters (VO2max and VO2peak)

Question 14

what 5 types of individual may a CPET be deemed unsuitable?

Answer 14

1. any individual that does not meet the ATS-ACCP guidelines for safe exercise testing/training
2. individuals on beta blockers
3. Individuals with lower limb joint conditions that limit their ability to cycle or run efficiently
4. individuals who exceed the maximum user weight limit for the cycle ergometer/other test equipment
5. individuals who cannot breathe normally in the face mask used during the test, despite a number of familiarisation attempts

Question 15

why is a CPET deemed unsuitable for individuals on beta-blockers?

Answer 15

because the HR parameters will not be accurate

Question 16

Give 3 reasons why a CPET would be used in a clinical setting

Answer 16

• to try and determine the origin of exercise limitation (i.e central, peripheral)
• to determine an individual’s risk profile for surgery
• to determine the efficacy of pre-rehab/rehabilitation

Question 17

what 3 ways can AT be determined after a CPET?

Answer 17

1. Gas exchange
2. V-slope method
3. Ventilatory equivalents (VEqO2)

Question 18

how can gas exchange be used to determine anaerobic threshold (AT)?

Answer 18

by using Respiratory exchange ratio.

AT is defined as the VO2 at teh piont where respiratory exchange ratio is stabilised above 1.0

Question 19

what is the v-slope method and how can it be used to determine AT

Answer 19

• V-slope method graphs VCO2 against VO2.
• it determines AT because the slope of relationship between VCO2 and VO2 are relatively linear, however at AT it changes

Question 20

what does ventilatory Equivalents (VEqO2) show?

Answer 20

• Ventilatory equivalents (VEqO2) shows how much ventilation is required to get a given volume of CO2 out of the body.

Question 21

outline 2 steps on how ventilatory Equivalents (VEqO2) determine AT

Answer 21

1. can be used to determine AT as VEqO2 will gradually fall during progressive exercise as ventilation-perfusion matching improves. VEqO2 increases later to get rid of CO2 produced from the buffering of lactate.
2. since there is no corresponding increase in VO2, VEqO2 starting to increase can denote AT

Question 22

what method do COMAP use to determine anaerobic threshold (AT)

Answer 22

COMAP use a combination of V-slope and Ventilatory-Equivalents methods

Question 23

old-male vs old-female, which is more likely to have a higher relative cardiorespiratory fitness and why?

Answer 23

old male, due to higher cardiorespiratory capacity and muscle mass

Question 24

Old male vs. younger male, which is more likely to have a higher relative cardiorespiratory fitness and why?

Answer 24

young male, due to higher cardiorespiratory capacity and muscle mass

Question 25

85kg young male vs. 65kg young male with identical absolute values, which is more likely to have a higher relative cardiorespiratory fitness and why?

Answer 25

65kg young male as absolute values are divided by body weight to achieve relative values, so would be dividing by a smaller number.

Question 26

old sarcopenic male vs old lean male, which is more likely to have higher relative cardiorespiratory fitness and why?

Answer 26

lean male, due to higher muscle mass