ISSN:
1522-9602
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Mathematics
Notes:
Abstract A model study is made of the contribution that continuing respiratory gas exchange makes to the alveolar plateau slope for O2 during air breathing. Calculations in the model of the O2 concentration appearing at the mouth during expiration, are performed for single breaths of air at constant flow rates 18 litres/min and 120 litres/min. At 18 litres/min the breathing period is 5 sec, the initial lung volume is 2300 ml, and the O2 uptake rate is 300 ml STPD/min; whereas at 120 litres/min these parameters are 4 sec, 1200 ml, and 1800 ml STPD/min respectively. In each case the initial lung O2 tension is taken to be 98 mm Hg. It is found that at 18 litres/min, the O2 concentration difference on the alveolar plateau over the last second of expiration is 0.4 mm Hg when gas exchange is omitted and 1.2 mm Hg when gas exchange is included in the model. At 120 litres/min, this difference is zero and 5.0 mm Hg respectively. The gas exchange component predicted from a corresponding well-mixed compartment model is the same at 18 litres/min (0.8 mm Hg) but is 6.0 mm Hg at 120 litres/min.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02460682
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