Exercise Capacity Flashcards
What is exercise?
purposeful, structured activity that involves gross muscular activity to improve physical condition
What is physical activity?
a holistic term that includes all (purposeful and incidental) muscular activity of all intensities.
What are activities of daily living?
basic independent self-care tasks done on a daily basis that require co-ordination, strength and range of motion
What happens if there is a deficiency in either ventilation or perfusion?
a significant impact on CO2 removal and blood oxygenation
How do you evaluate exercise capacity in clinical populations?
- cardiopulmonary exercise test
- 6 minute walk test
- incremental shuttle walk test
What is involved in a cardiopulmonary exercise test?
- use a cycle ergometer or treadmill
- under close clinical supervision in a controlled environment
- ECG, ventilation, O2 and CO2 routinely measured
What are the outputs of a cardiopulmonary exercise test?
- ECG changes monitored throughout
- peak VO2 (usually primary outcome)
What are the advantages of doing a cardiopulmonary exercise test?
- quantifies performance in relation to metabolism
- precise and reproducible
- continuous monitoring for safety
What are the disadvantages of doing a cardiopulmonary exercise test?
- requires skilled technical support (calibration)
- very expensive (both initial and ongoing costs)
- needs a dedicated space
What is involved in a 6 minute walk test?
- uses a 20-30m flat course
- aim: cover the greatest distance as possible in 6 minutes
- externally timed by assessor
- sub-maximal test
What are the outputs of a 6-minute walk test?
- total distance walked in 6 minutes (primary outcome)
- perceived exertion scales, heart rate and pulse oximetry
What are the advantages of doing a 6-minute walk test?
- patient-driven pace (speeding up, slowing down and rest is ok)
- cheap to deploy
- validated in many populations
What are the disadvantages of doing a 6-minute walk test?
- requires a significant, unobstructed course - often a corridor
- unregulated location
What is involved in an incremental shuttle walk test?
- uses a 10m circut
- externally paced by an audio recording (like a bleep test)
- each minute has one extra length than the previous one
What are the outputs of an incremental shuttle walk test?
- total distance walked before volitional end (primary)
- percieved exertion scales, heart rate, pulse oximetry
What are the advantages of doing an incremental shuttle walk test?
- cheap to deploy
- validated in many populations
- external pacing helps to achieve maximum levels
What are the disadvantages of doing an incremental shuttle walk test?
- requires an unobstructed course
- often done in corridor
- for some the incremental nature is difficult
- ceiling effect of 1020m
- patient can be penalised for poor pace management
Which systems in which failure can lead to reduced exercise capacity?
- neurological
- respiratory
- cardiovascular
- muscular
How can neurological deficits lead to a reduced exercise capacity?
- motor control
- co-ordination
How can respiratory deficits lead to a reduced exercise capacity?
- ability of ventilation
- pulmonary perfusion
- gas exchange
How can muscular deficits lead to a reduced exercise capacity?
- local perfusion
- muscle cell enzymes
What are exercise tests used for?
to monitor disease severity/progression and response to treatment
What is the impact of supplemental oxygen on exercise capacity?
can improve exercise capacity
- doesn’t always relieve breathlessness
How is the output of a CPET/CPEX represented?
- nine-panel chart
- relationship between key measured and derived variables
