Describe the production of carbon dioxide in the body (60% of marks).
What are the physiological reasons why the PaCO2 may be high? (40% of marks)
The main points for a pass include a brief description of the citric acid cycle and a list of facts
such as storage of CO2 (120L), production (200ml/min) and that 2 molecules of CO2 are
produced for 1 molecule ATP. A statement that PaCO2 is proportional to CO2
production/alveolar ventilation would help answer the second part. An example of increased
CO2 production is fever, and of decreased alveolar ventilation is increased anatomical dead
space.
Syllabus B1h 2e
References:
Power and Kam 2nd edition p78-79,101
Stoelting and Hillier 4th edition p790-791
Nunn 6th edition p148-156