CROUP. 21 



In any juvenile larynx which we may cut out ci the body, the glottis 

 is capable of being completely closed by the application of powerful 

 suction to the trachea. As it is of the utmost importance, in the treat- 

 ment of croup, for us to know whether false membranes occlude the 

 glottis, or whether palsy of the laryngeal muscles, by cedematous infil- 

 tration, be the main cause of the dyspnoea, we must carefully note 

 whether inspiration and expiration are in equal degree obstructed, or 

 whether inspiration alone be laborious, and expiration free. In the 

 former, and most common case, false membranes clog the rima glottidis, 

 impeding both exit and entrance of the air ; in the latter, crippling of 

 the muscles is the chief cause of the dyspnoea. Upon rarefaction of the 

 air within the trachea during inspiration, the inflowing current, through 

 the nose and mouth, forces the folds of the glottis together ; but expira- 

 tion follows freely, as the air, when expired, drives the vocal chords apart, 

 without any need of muscular aid. Let us bear in mind, too, that the 

 posterior crico-arytenoid muscles, which open the rima glottidis, are more 

 easily paralzyed when the mucous membrane of the pharynx, which 

 covers them, takes part in the inflammation. Thus, it is easily seen why 

 those cases of croup which the French alone admit to be true croup, 

 cases in which croup-membrane can be seen upon the pharynx, must be 

 by far the most dangerous. 



The wide gaping of the glottis during inspiration, when the laryn- 

 geal muscles are acting normally, of which I have been able to convince 

 myself as often as I have looked in the laryngoscope, has materially 

 strengthened my conviction of the correctness of my theory, that palsy 

 of the muscles of the glottis forms an important element in the dyspnoea 

 of croup. 



It is difficult to say whether any real pain in the larynx forms a 

 symptom of croup. The clutching of the child at its throat may depend 

 upon the desire to remove the impediment to its breathing, which it in- 

 stinctively perceives. In the beginning of the disease, the expectora- 

 tion, which is usually scanty, rarely contains masses of shreds, or of cohe- 

 rent false membrane. The pulse, at first, is generally full, hard, and of 

 moderately increased frequence ; the face is flushed, and the tempera- 

 ture of the body elevated. 



Croup, in a great many cases, exhibits decided remissions in the 

 morning, and through the course of the day, which might almost seem 

 Intermissions. (Hence the homoeopathists premise that their medicines 

 will not evince their wonderful effect until after a lapse of several hours.) 

 Toward morning the respiration becomes more free. The voice returns. 

 The cough is less frequent ; it is hoarse, but not without sound. The 

 fever abates; the general condition appears almost undisturbed; and 

 only the thin piping, or the still suspicious tone of the cough, remains. 



