SKM in health and disease CPET

Question 1

What are the main steps of the pre-test before a CPET is carried out?

Answer 1

• Calibration of equipment fot gas and volume
• Ensure the bike is set up fot the patient/participant (i.e., seat height/ handlebar position)
• Ensure there are no leaks around the edges of the mask and that it is comfortable for the patient/participant
• Ensure the patient/participant is fully aware of what the test will entail
• Determine the ramp setting (e.g., W/min increase) based on patient/ participants age, gender and physical activity levels
• Aim for a test that is 8-12 min in duration (excluding warm up and recovery)

Question 2

What are the main steps during the CPET test?

Answer 2

• Ensure safety monitoring is working (ECG/blood pressure) and O2 saturation
• Provide verbal encouragement for patients/participants to reach true max effort and maintain the required cadence (50-60 rpm)
• If conducting a V02 max test, ensure the variables of RER and O2 consumption (alongside rating of perceived exertion (RPE) and HR)) reach the required values before test is complete

Question 3

What are the steps post test for CPET?

Answer 3

• Remove the face mask at the earliest opportunity
• Encourage patients/ participants to keep their legs moving with the resistance to the pedals removed
• Ensure patients/ participants complete the recovery phase for their specific protocol
• Provide the patient/ participants somewhere comfortable to sit after dismounting the bike, and ensure they have returned to baseline CV parameters (HR and BP) before they leave the unit

Question 4

What is the common analysis in CPET?

Answer 4

• Anaerobic threshold
• VO2 max
• VO2 peak
• Max wattage - highest resistance worked against during the test
• HR max - highest HR during the test
• Exercise capacity/ tolerance - time to the end of the test

Question 5

What are the 5 key stages for conducting a CPET?

Answer 5

1. Calibration
2. Ergonomics
3. Warm up
4. Test phase
5. Recovery

Question 6

What is the main purpose of a CPET?

Answer 6

• To determine cardioresp fitnes
• gold standard measure of CRF/ overall physical fitness
• Can be used to determine the fitness of diff individuals/ groups/ deteremine the effect of an intervention/situation on CRF

Question 7

What are the 2 main physiological mechanisms assessed by a CPET?

Answer 7

• O2 delivery (heart and lungs)
• O2 uptake and utilsation (by SKM)

Question 8

What is V02 max?

Answer 8

• the max rate of o2 consumption attainable during physical exertion
• common criteria :
• HR less than 10 beats/min / less than 5% of the age-predicted (220-age) max; ii) blood lactate conc >8 mM
• RER >1.10
• No further increase in o2 consumption despite an increase in exercise intensity and volitional exhaustion/ an inability to maintain desired cadence

Question 9

What is VO2 peak?

Answer 9

• VO2 max is max rate of O2 consumption acheived during a CPET without further criteria
• VO2 peak is used more commonly than VO2 max in patient populatuons/ those with physiological limitations due to the relative high intensity work needed to acheive VO2max

Question 10

What is anaerobic threshold?

Answer 10

• The level of 02 consumption at the point which, during incremental exercise, aerobic enerfy production needs to be supplemented by anaerobic mechanisms, causing a sustained increase in lactate and metabolic acidosis

Question 11

What are the strengths and limitations of V02 max?

Answer 11

• Gold standard measure of CRD
• Difficult to achieve in non-athletic populations

Question 12

What are the strengths and limitations of VO2 peak?

Answer 12

• Achievable by all
• Subjective based on participant effort on the day as not based on defined physiological parameters

Question 13

What are the strengths and limitations of AT?

Answer 13

• Defined physiological ethreshold not impacted by participant effort
• Defined thresholds established in relation to clinical challenges
• Contention in the literature as to what this represents
• More complicated to determine than the other measures

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Question 14

In which individuals may a CPET be deemed unsuitable and why?

Answer 14

• Any individual who does not meet the ATS-ACCP guidelines for safe exercise testing/ training
• Primarily based around prior/exisiting CV conditions
• Individuals on beta blockers as HR parameters - will not be accurate
• Individuals with lower limb conditions that limit their ability to cycle efficiently

Question 15

vi. When may a CPET be used in a clinical setting?

Answer 15

• To try and determine the origin of exercise limitations
• To determine an individual’s risk profile for surgery
• To determine the efficacy of pre/rehabilitation (cardiac rehabilitation)

Question 16

viii. How is AT determined after a CPET?

Answer 16

1. Gas exchange
2. V slope method - VCCO2 vs VO2
3. Ventilartory equivalents (VEqO2) - shows how much ventilation is needed to get a given volume fo CO2 out of the body
   — will gradually fall during progressiev exercise as VP matching improves

Question 17

Why do males have a higher relative CRF?

Answer 17

• Have a higher cardiorespiratory capacity and muscle mass

Question 18

Why do lighter/ younger males have a higher relative CRF?

Answer 18

Lighter (kg)- Absolute values are divided by body weight to achieve relative values
Younger: High cardioresp capacity and muscle mass
Lean individual vs old sarcopenic male
- lean male has higher cardio resp cap due to higher muscle mass