The effect of temperature on gas trapping in excised lungs.
Frazer-DG; Morgan-JJ; Franz-GN; Turick-CE; Weber-KC
Respir Physiol 1982 Oct; 50(1):13-22
The possibility that heating or cooling the lung could have any consistent measurable effect on lung pressure/volume (Pl-Vl) curves and on the gas trapping mechanism was investigated using male Long- Evans-Hooded-rats as study animals. Gas trapping was determined following ten successive inflation/deflation cycles at the same constant ventilation rate at 17, 27, 37, and 42 degrees-C. Also, the effects of five different ventilation rates were investigated at 17, 27, and 37 degrees-C. The results indicated that temperature did affect gas trapping in the lung in a systematic manner. When lungs were repeatedly ventilated in the same manner at either 17 or 27 degrees-C, only a relatively small change was noted in the amount of gas trapped in the lung after ten cycles, indicating that there was little time dependence. Holding the temperature at 37 or 42 degrees-C, the amount of trapped gas decreased significantly as the lungs were repeatedly ventilated, probably due to the time dependent loss of surfactant material in the lung. Both a reduction in gas trapping and an increase in the lung recoil pressure with time were noted at 37 and 42 degrees-C. The authors suggest that if lung hysteresis responds to temperature and ventilation rate changes in a manner similar to that observed for gas trapping, it may explain why other investigators found little dependence of hysteresis on temperature when the lung was ventilated very slowly at room temperature and at 37 degrees-C.
NIOSH-Author; Pulmonary-function; Lung-function; Physiological-response; Respiratory-gas-analysis; Laboratory-animals; Temperature-effects;
Author Keywords: Pressure-volume curves; Temperature effects; Rat; Trapped gas; Respiratory mechanics
D. G. Frazer, Appalachian Laboratory for Occupational Safety and Health, National Institute for Occupational Safety and Health, Morgantown, WV 26505, U.S.A.