On asthma : its pathology and treatment / by Henry Hyde Salter.

  • Henry Hyde Salter
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: On asthma : its pathology and treatment / by Henry Hyde Salter. Source: Wellcome Collection.

    94/500 (page 78)
    inspiration being longer than the expiration, as is normally the case, the expii'ation is longer than the inspiration; that while the inspii'ation is very little longer than natural, some- times even shorter, the explication, instead of being the short and gentle collapse of natural breathing, is a difficult and prolonged effort by which the air is slowly and painfully driven out of the lungs; and so great sometimes is this lengthening out of the expiratory act that I have known it four or five times as long as the inspiration, occupying nearly the whole respiratory interval, instead of being half the length of it, or less, as in health. I know nothing like this modi- fication of the respiratory rhythm in any other disease; I believe it is peculiar to asthma. In phthisis and emphy- sema there is a certain amount of prolongation of expiration, but nothing like this. In the most intense asthmatic breathing the difficulty of getting the air out of the chest is so great, the expiratory movement (with all its effort) so slight, and the quantity of air expelled so small, that, as if aware that the chest would never be emptied at that rate in time for the next inspiration, a violent involuntary effort comes to the assistance of the expiration and pumps out the remainder of the air with a sudden jerk. This termination of a prolonged, ineffectual, and almost motionless expiration by a sudden expiratory jerk is characteristic of the intensest asthma, and occm's in no other form of dyspnoea whatever; whenever we see it we may be sm^e that the bronchial spasm is extreme. It is at expiration, too, that the asthmatic ex- periences the greatest distress. Now, why should the impediment to respiration in asthma tell more on expn-ation than inspiration ? Either there must be a greater obstacle to the egress than to the ingress of air, or, the obstacle being the same, the expiratory force is feebler than the inspiratory. The former of these suppositions I do not believe; I do not believe, for the reasons I have men-