Evaluating Exercise Capacity

Question 1

what is the difference between exercise, physical activity and activities of daily living?

Answer 1

exercise= purposeful, structured activity that involves gross muscular activity to improve physical condition

physical activity= holistic term that includes all muscular activities of all intensities

AODL= basic independent self-care tasks done on a daily basis that require coordination, strength and range of motion

Question 2

what factors affect the capacity to exercise within the body?

Answer 2

Question 3

what can exercise limitations be caused by?

Answer 3

deficits in several systems

• Neurological
  
  • Motor control, coordination
• Respiratory
  
  • Ability lung ventilate, pulmonary perfusion, gas exchange between lungs and blood
• Cardiovascular
  
  • Ability heart to receive blood from lungs and pump muscles
• Muscular
  
  • Local perfusion, muscle cell enzymes

Question 4

what is affected when there is a ventilation-perfusion mismatch?

Answer 4

impact removal CO2 and oxygenation

efficient gas exchange needs maximum V/Q coupling

Question 5

what changes in lungs when there is less ventilation?

Answer 5

Ppl is more negative

greater transmural pressure gradient

alveoli larger + less complient

Question 6

what happens in the lungs when there is more ventilation?

Answer 6

Ppl is less negative

smaller transmural pressure gradient

alveolar small & more compliant

Question 7

what happens when there is a lower perfusion flow rate?

Answer 7

lower intravascular pressure

less recruitment

greater resistance

Question 8

what happens when there is a higher perfusion flow rate?

Answer 8

higher intravascular pressure

more recruitment

less resistance

Question 9

where are ventilation and perfusion greatest?

Answer 9

at base of lungs

Question 10

where is V/Q lowest?

Answer 10

at base of lungs

Question 11

what are the tests used to evaluate exercise capacity?

Answer 11

cardiopulmonary exercise test

6-minute walk test

incremental shuttle walk test

Question 12

what is the cardiopulmonary exercise test?

Answer 12

1. Uses cycle ergometer or treadmill
2. Intensity incremental
3. Undertake under clinical supervision
4. ECG, ventilation, O2 and CO2 measured routinely

Question 13

what are the outputs of the cardiopulmonary exercise test?

Answer 13

Peak VO2 primary outcome

ECG changes monitored

Question 14

what are the advantages of the cardiopulmonary exercise test?

Answer 14

1. Quantifies performance in relation to metabolism
2. Precise and reproducible
3. Continuous monitoring for safety

Question 15

what are the disadvantages of the cardiopulmonary exercise test?

Answer 15

1. Requires skilled technical support
2. Very expensive
3. Needs dedicated space

Question 16

what is the 6-minute walk test?

Answer 16

1. 20-30m flat course
2. Objective to cover greatest distance as possible in 6 minutes
3. Externally timed by assessor
4. Sub-maximal test

Question 17

what are the outputs of the 6-minute walk test?

Answer 17

1. Primary outcome is total distance walked in 6 minutes
2. Secondary variables
   
   1. Perceived exertion scales, Heart rate, Pulse oximetry

Question 18

what are the advantages of the 6 minute walk test?

Answer 18

1. Patient-driven pace
2. Cheap to deploy
3. Validated in many clinical populations

Question 19

what are the disadvantages of the 6 minute walk test?

Answer 19

1. Requires significant unobstructed course
2. Pace is not regulated

Question 20

what is the incremental shuttle walk?

Answer 20

10m circuit

externally paced by audio recording

each minute has one extra length than previous minute

Question 21

what are the outputs of the incremental shuttle walk test?

Answer 21

primary= total distance walked before volitional end

secondary= perceived exertion scales, heart rate and pulse oximetry

Question 22

what are the advantages of the incremental shuttle walk test?

Answer 22

1. Cheap to deploy
2. Validated in many clinical populations
3. The external pacing helps some to achieve maximum levels

Question 23

what are the disadvantages of the incremental shuttle walk test?

Answer 23

1. Requires unobstructed course
2. For some incremental nature is difficult
3. Ceiling effect of 1020m
4. Patient can be penalised for poor pace management

Question 24

what is used to calculate degree of breathlessness?

Answer 24

MRC dyspnoea scale

Question 25

how can exercise testing be used in clinical populations?

Answer 25

* Exercise tests can be used to monitor disease severity/ progression and response to treatment * An assessment for ambulatory oxygen could be carried out using 6MWT * If patient is stable pulmonary rehabilitation may be prescribed to increase exercise capacity

Question 26

what is required to prescribe long term oxygen therapy (LTOT)?

Answer 26

use \>15 hours/day this would include measure of blood gasses