Pulmonary Systems

Pulmonary Systems - Abbreviations used in respiratory...

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Abbreviations used in respiratory physiology: ( V = volume, mL or L; ˚V = flow , mL/minute or L/minute) April Apperson, UCSD SOM OESS AV O2 D = arterial-venous blood O 2 concentration difference = ( C aO2 – C vO2 ) = ˚V O2 / C.O. for CO 2 , this would be VA CO2 D = venous-arterial CO 2 difference = ( C vCO2 – C aCO2 ) = ˚V CO2 / C.O. AWR = airway resistance; AWR = (P B – P A )/˚V E , since the numerical difference between P B and P A is the same during inspiration and expiration; for a single breath , AWR = ( P B – P A )/(inspired air flow) = ( P A – P B )/(expired air flow) C gas •for a gas mixture, C gas = concentration of a specific gas, measured as %; e.g, in air, C O2 = 21%, C N2 = 79%; •if used for gas concentration in blood , concentration = total gas in blood = dissolved gas + any reacted gas; •for inert gases (e.g., N 2 O, gas anesthetics), Ca gas = dissolved gas = (Pa gas )•(gas solubility in blood) •for gases that react with blood elements, Ca -gas = dissolved gas + reacted gas e.g., C O2 = HbO 2 + dissolved O 2 = (%S Hb )([Hb])(1.39) + (Pa O2 )(.003), where .003 = solubility of O 2 in blood. Ca gas = systemic arterial concentration (content) of a gas Ca O2 = HbO 2 + dissolved O 2 = [(%S Hb )([Hb])(1.39) + (Pa O2 )(.003)] Ca CO2 = [(Pa CO2 )(.067) + (CO 2 present as HCO3 - ) + (CO 2 present as carbamino on Hb)] Cc’ gas = gas concentration at the end of the pulmonary capillary, which is normally ≈ Ca gas , e.g. Cc’ O2 , Cc’ CO2 , Cc’ CO Cv gas = mixed venous concentration of a gas, which must be measured from the pulmonary artery , e.g., Cv O2 , Cv CO2 . ; for normal levels of Cv O2 , dissolved O 2 is low enough to ignore, so Cv O2 (%S Hb )([Hb])(1.39) C L = compliance of the lung ≈ (change in lung volume)/(change in transmural pressure); transmural pressure in the lung = transpulmonary pressure (TPP) = (P A – IPP), so C L = ∆volume/∆(P A – IPP)
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This note was uploaded on 09/14/2011 for the course PHARM ps taught by Professor Staff during the Spring '11 term at UCSD.

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Pulmonary Systems - Abbreviations used in respiratory...

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