A graphic analysis of respiratory heat exchange.
A new graphic representation of respiratory heat exchange is proposed using the concept of equivalent temperatures directly related to enthalpy values. On such a diagram it is possible to 1) compute the value of the heat exchange (delta H) knowing the inspired temperature (TI) and the partial pressure of water vapor (PIH2O) [or the relative humidity (rhI)] of inspired gas; 2) estimate the variation in delta H following a given variation in TI and PIH2O or, inversely, to choose the variation in TI and PIH2O necessary to obtain a given variation in delta H; 3) dissociate inspiratory and expiratory exchanges and to evaluate the efficiency of the respiratory heat exchange process in different environmental situations; and 4) easily compare the results of different studies published on respiratory heat exchanges in humans or other animal species.
Laboratoire de Physiologie, Université de Bordeaux-II, France.
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Varene
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Kays
D000818:Animals; D001833:Body Temperature Regulation; D006801:Humans; D008954:Models, Biological; D012143:Respiratory Physiological Phenomena; D013816:Thermodynamics