The effect of temperature on gas trapping in excised lungs

In this study the effect of temperature on gas trapping in excised lungs was examined with two types of experiments in rats. In the first, changes in gas trapping following ten successive inflation-deflation cycles at the same constant ventilation rate were examined at 17, 27, 37 and 42 degrees C. In the second, the effects of five different ventilation rates at temperatures of 17, 27 and 37 degrees C were determined. The fraction of gas trapped in lungs repeatedly ventilated for ten inflation-deflation cycles at constant ventilation rates remained nearly constant with time at 17 and 27 degrees C but decreased with time at 37 and 42 degrees C. The amount of gas trapped in the lung at 27 degrees C fell with the logarithm of increasing ventilation rate. Lowering the temperature shifted this relationship toward lower ventilation rates while increasing the temperatures caused an apparent shift toward higher ventilation rates.