APPENDIX IV. STANDARD SYMBOLS IN RESPIRATORY PHYSIOLOGY 



The following symbols conform to standards adopted by pulmonary physiologists, as published in Federation Pro- 

 ceedings 9:602, 1950. Use of these symbols throughout the HANDBOOK OF RESPIRATION was not feasible because 

 of mechanical limitations in the preparation of copy. 



Primary Symbols 

 (Large capital letters) 



Secondary Symbols 

 (Small capital letters) 



V = gas volume 



V = gas volume/unit time 

 P = gas pressure in mm Hg 



F = fractional concentration in dry gas phase 



f = respiratory frequency, breaths/unit time 



R = respiratory exchange ratio, VCO2/VO2 



I - inspired gas 



E = expired gas 



A = alveolar gas 



T = tidal gas 



D = dead space gas 



B = barometric 



STPD = standard temperature and pressure, dry 

 (0°C, 760 mm Hg) 



BTPS = body temperature and pressure, satu- 

 rated with water vapor 



ATPDj ambient temperature and pressure, dry 



ATPS or saturated 



Va (alveolar ventilation) is in L/min (BTPs). VOj and Vco^ are in ml/min (stpd). Dash (-) above any symbol 

 indicates a mean value. Dot (") above any symbol indicates a time derivative. 



The following conventions for symbols denote location and molecular species: 



1. Localization in the gas phase is represented by a small capital letter immediately following the principal 

 variable. 



2. Molecular species is denoted by the full chemical symbol, printed in small capital letters immediately 

 following the principal variable. 



3. When specification of both location and molecular species is required, the first modifying letter is used for 

 localization and the second for species. In the latter case, the chemical symbol appears as a subscript. 



Contributor : Swann, H. G. 



Reference: Comroe. J. H., Jr., et al, Fed. Proc. 9:602, 1950. 



APPENDIX V. RESPIRATORY EQUATIONS 

 I. O2 consumption and CO2 production: 



(I) V02 - Ve 



[Fio2(1-Feco2)-Feo2(1-FIco2)1 



[ll 



, [FEco,(l-Fio2)-Hic02a-FEoJl 

 (2) VCO2 = Ve = 



(1-Fio -F1CO2) 



ll] 



390 



