When the disease invades the larynx the danger is at once imminent, and the question of operative interference has to be considered. In cases of laryngeal diphtheria (true membranous croup), tracheotomy is the only hope left to us—the child's last chance for his life. Directly, therefore, we feel sure that the larynx is involved, the operation should be under taken without unnecessary delay. It must be remembered, however, that clyspncea alone is not always a sufficient indication for this step. As has been before explained (see p. 99), lividity and laboured breathing are some times due to an impediment to the circulation of blood through the lungs. In such a case there is no want of air, and opening the larynx will bring no relief to the child's distress. The signs by which these two very differ ent conditions are indicated have been already enumerated. When, there fore, we notice that the respiratory movements have become laboured, with great recession of the epigastrium and the soft parts of the chest in inspi ration ; that the breathing is hissing and stridulous, the voice whispering, and the cough husky and stifled, the operation should be no longer post poned. We have nothing to hope for in delay ; on the contrary, the earlier the tube is introduced into the trachea, the sooner will the child's suffering be relieved and the better be his prospect of a cure. The success which often attends the operation of tracheotomy in membranous croup is very encour aging, and even in the case of an infant we should not hesitate to have re course to it. Even at a later stage, when the child seems to be at the last gasp, the operation should still be undertaken, for nothing short of actual death can render it hopeless.
In performing the operation, if the asphyxia is far advanced anaesthetics will be unnecessary. If the lividity is not marked, chloroform should be ad ministered, and if the child be made to inhale it gradually so that he does not breathe in too large a volume at first, the anaesthetic may be given without fear. The details of the operation, as they come under the depart ment of the surgeon, need not be here referred to ; more especially as they will be found recorded at length in all works on practical surgery. It may be only remarked that the size of the tube to be employed should be the largest which can be introduced without violence ; that it should be as short as is consistent with safety ; and that before its introduction the tra chea and larynx must be thoroughly cleansed by introducing a feather soaked in a warm solution of carbonate of soda through the opening. The importance of this precaution has been strongly insisted upon by my col league Mr. Parker in his well-known treatise.
The relief afforded by the operation is usually complete. If the diffi culty of breathing still continues, it is a sign that the trachea is obstructed below the opening, and that there is probably extension of the false mem brane far down the ramifications of the bronchi.
The after-conduct of these cases is of the utmost importance, as success depends upon judicious nursing and scrupulous attention to small points of treatment. Our object is to furnish a constant supply of properly pre pared air to the lungs. The utmost care has therefore to be taken to maintain the inspired air at a suitable temperature and degree of mois ture, and to see that the tube is kept in place. - Moreover, the strength of
the child has to be supported, and the treatment of the constitutional dis ease to be continued.
The child should remain in his tent bedstead, in a room of the temper ature of 70° ; and the croup-kettle must be kept in action on a side table so as to moisten the air he breathes. A disinfectant should be always ad ded to the water in the boiler, as already directed. The kettle must not be placed too near the Led. If the air is kept constantly saturated with va pour, the excess of moisture tends to depress the child. Mr. Parker's rule is a good one, viz., that we should be guided by the amount of tracheal secretion. If this is small, the amount of steam can be increased.
The wind-pipe and tracheotomy tube must be kept patent. Free se cretion is to be desired, but this must not be allowed to accumulate so as to interfere with the passage of air. It is important to apply weal: alkaline solutions, such as the bicarbonate of soda (ten to twenty grains to the ounce) with a hand spray-producer at short intervals, so that the inhaled air may be saturated with the solvent. The spray at once produces free secre tion into the windpipe ; and the repeated use of this agent prevents the mucus from accumulating and becoming inspissated so as to block up the air passages. It is curious to notice how the dry mucous membrane becomes almost instantly relieved by this Means. After a few minutes' use of the spray, a feather soaked in the same solution must be passed into the trachea through the silver tube, so as to clear away loosened membrane and mucus. The introduction of the feather causes spasmodic cough, but this is not to be regretted, as the violent expulsive action usually relieves the patient of large portions of membrane, and greatly aids in clearing the trachea. If signs of obstructed •breathinu are noticed at any time, we may conclude that either the trachea or the tracheotomy tube is becoming obstructed, or that the latter is displaced. Measures must then be taken at once to rem edy the fault.
The inner tube should be removed every hour or two and cleaned with a feather clipped in the warm alkaline solution. The outer tube will re quire cleaning only once in the twenty-four hours. When it is removed, advantage should be taken of the opportunity to pass the moistened feather upwards into and through the glottis, so as to clear the upper part of the, windpipe. At this time, also, the wound can be examined for any un healthy appearance. As a rule, the outer tube can be easily taken out and replaced, for the tissues around the opening soon become matted to gether by inflammatory exudation, and the orifice remains patent after the tube is withdrawn. After each cleaning the tube should be replaced by another of different length, so that the child may wear a short and a long tube alternately. If the tube be of silver, it should be examined for black discolourations, as these are due to morbid action at the corre sponding part of the wound, and will therefore, as Mr. Parker has pointed out, be often valuable guides in indicating the parts to which our attention should be directed.