Approximately 30,000 mmol of carbon dioxide are produced per day.
Equivalent to 20.8 mmol per minute.
Assume a total body water content for a 13 year old girl of 35 litres.
Then 20.8/35=0.595 mmol of carbon dioxide per min per litre.
To convert mmol of carbon dioxide to pCO2 mmHg divide by 0.03,
0.595/0.03=19.8 mmHg.
Hence breath holding for approx one minute will increase the pCO2 value by
appro'20 mmHg, consistent with Mike Addison's hypothesis.
John Martin
Dept of Clinical Chemistry
Royal Bolton Hospital
Email [log in to unmask]
|