Resistance to inspiration—its effects on respiration in man

VERY little work has hitherto been published on the experimental use of a resistance to respiration in man. Davies, Haldane and Priestley [1919] published the results of a series of experiments with a small number of subjects, using both inspiratory and expiratory resistances. Cannisters packed with cotton wool were used, which they state gave a resistance through which the air flow varied directly as the driving pressure. The usual response to respiratory resistance was found to be slowing and deepening of the breathing. With excessive resistance, the respiratory centre became fatigued, and the breathing, as a result, became shallower and more frequent. Measurements of the resistances used are given in inches of water, presumably the driving pressure exerted during respiration. METHOD.