I was just told yesterday that I have to do a short lecture on Friday
morning at work over complicated exercise testing. All four of us have
a different aspect of testing that we are covering. I get the pleasure
of covering CO2 production and minute ventilation.
Some people have wondered what I do now in my new position at
Children’s so you can have some kind of clue as to what I do in the
pulmonary physiology lab (a recent name change of the lab) here is part
of what I will be talking about on Friday:
CO2 output (VCO2) during exercise is determined by factors similar to
those that govern O2 uptake: cardiac output, CO2-carrying capacity of
the blood, and tissue exchange are major determinants. However, because
CO2 is much more soluble in tissues and blood, CO2 output measured at
the mouth is more strongly dependant on ventilation that on VO2 (oxygen
consumption). In addition to this, because dissolved CO2 is a weak acid,
the body uses CO2 regulation to compensate for acute metabolic acidosis,
which affects the pattern of VCO2 as work intensity increases above the
point of anaerobic metabolism…….During progressive exercise VO2
increases nearly as much as does VO2 over the lower work rate range,
with an average VCO2-VO2 relationship of slightly less than 1.0. It
should be recognized that the slope of the VCO2-versus VO2 relationship
is not equal to the respiratory exchange ratio, as the relationship
usually has a small positive intercept on the VO2 axis…..VE has been
demonstrated to be closely proportionally coupled to VCO2 during
exercise, it is useful to analyze Ve in relation to VCO2……
So what are your thoughts on this?
I concur 😉