CPET

Question 1

How can you determine maximal effort on CPET?

Answer 1

1. achieving >90% predicted work on basis of age, height, weight, sex.
2. Achieving >80% predicted heart fate
3. RER >1.15.
   RER= Respiratory Exchange Ratio = VCO2/VO2

Question 2

Vo2 peak of what level is considered greater risk of peri-operative complications?

Answer 2

<15ml 02 kg-1min-1

Question 3

What is the significance of Vo2-work relationship?

Answer 3

As resistance added to cycle ergometer increased, o2 consumption increased 10ml 02 min-1. The increased in Vo2 should parallel the increase in work

Question 4

What is the AT? And what level is greater risk of perioperative complications?

Answer 4

Anaerobic threshold. The point at which the o2 demand of the muscles exceeds the ability of the cardiopulmonary system to supply o2. Muscles generate ATP which is buffered by HCO2 generating co2. AT is reached when the VCO2 disproportionately rises to VO2.
An AT of <10 ml 02 kg-1 min -1 is considered greater risk of peri-operative complication

Question 5

Ventilatory limitation on graph trend

Answer 5

Linear to AT followed by disproportionate increase driven by co2 production. Ventilatory capacity not limited in healthy patients but limited in obstructive/restrictive defect. In normal patient maximum VE does not exceed 80% of maximum ventilatory voluntary ventilation.

Question 6

What would you expect to find on CPET in heart failure?

Answer 6

mVO2 - decreased
AT - decreased
HR peak - Normal
mVE - Normal
02 - Normal
VE/VCo2 at AT - increased

Question 7

What would expect in lung disease?

Answer 7

mVO2 - decreased
AT - Normal
HR peak - decreased
mVE - Increased
02 - Decreased
VE/VCo2 at AT - increased

Question 8

What would you expect to find CPET pulmonary vascular disease?

Answer 8

mVO2 - decreased
AT - decreased
HR peak - Normal/decrease
mVE - Normal
02 - decreased
VE/VCo2 at AT - increased

Question 9

What would you expect to find on CPET in obesity?

Answer 9

mVO2 - decreased - but normal for IBW
AT - Normal
HR peak - Normal/decrease
mVE - Normal/increase
02 - Normal
VE/VCo2 at AT - Normal

Question 10

What would you expect to find on CPET in decondtionned patient?

Answer 10

mVO2 - Decreased
AT - normal/decreased
HR peak - Normal/slight decrease
mVE - Normal
02 - Normal
VE/VCo2 at AT - Normal