SPECIAL SYMPTOMS CONNECTED WITH THE LUNGS AND AIR-TUBES.
Cough is a symptom of pally different affec tions, and its treatment depends on its cause. It consists of a deep breath followed by closure of the glottis, and a series of rapid expiratory efforts. It is the result of a nervous action originating in an irritation of the ends of sen sory nerves distributed to the inner surface of the larynx. The impression is conveyed to the centre for breathing in the medulla (p. 150), and from thence impulses pass to the muscles of respiration and to those of the glottis, by which the cough is produced.
The irritation which begins the process may be owing merely to cold air entering the larynx and passing over an inflamed surface. It may be that the surface is not inflamed, but that the indrawn air contains irritating particles.
Again, it may be caused by the tickling of some phlegm poured out by an inflamed mem brane, or of some matter swept up from the lungs.
It may also be a mere nervous affection, or due to some condition of the blood, as in gout and rheumatism, or the nervous irritation may arise from disordered stomach or liver.
The cough is thus either dry, that is, un accompanied by spit, or moist when it is so accompanied. It varies in character. It is spasmodic in whooping-cough and croup. The "whoop " which attends the former readily dis tinguishes it, and the loud brassy sound of the latter is characteristic. In cough from obstruc tion of the air-passages arising, for example, from an inflamed and swollen lining membrane, such as common cold produces, it is also spas modic and wheezy. Where the vocal cords are rough, owing to swelling, it is harsh, barking, and hoarse, and when the cords are covered with membrane, as in diphtheria, it is wheezy and voiceless.
The treatment depends so entirely on the cause that it is impossible to give any special treatment for the mere symptom. It may be noted, however, that one of the commonest and most troublesome coughs attends slight cold from swelling and irritability about the larynx. Warm poultices over the front of the neck greatly soothe and relieve it. If that fail, a piece of flannel sprinkled with turpentine, or with soap and opium liniment, should be placed directly over the larynx on the neck. If a mustard poultice be used, and it is often very efficient, it should be placed lower down at the top of the breast-bone. A cough due to an inflamed larynx is usually dry, and if obstinate, great pain is experienced in a line across the front of the chest, the line of the diaphragm (p. 345), occasioned by the severe and constant spasmodic movement of the chief muscle of breathing. Other means failing, a dose of 10 to 15 drops of laudanum (only to adults) will stop it more or less for a time. This,
however, would be the worst possible thing to give were the cough attended with much spit, as in bronchitis, in thonmation of the lung, &c. It is the matter coming up from the lung that is the irritating agent in such cases. Laudanum and other similar soothing drugs would simply blunt the nerves to the presence of the matter, which would not be expelled, but be allowed to remain in the tubes, and might by blocking them seriously aggravate the state of the patient. In such cases what is desired is to aid in the expulsion of the matter without serious efforts of coughing. For this purpose warm applica tions to chest and throat are valuable, and drugs like ipecacuanha wine (5 to 10 drops) and syrup of squills.
A very intractable form of cough is produced by relaxed throat and elongated uvula. The long uvula touches the tongue and maintains a constant tickling. The sprays recommended for clergyman's sore throat (p. :390) are useful here. The best treatment, however, is to snip off a piece of the too-long uvula with scissors, which occasionally causes the cough to stop as if by magic.
Difficulty of Breathing (Dyspncea, Greek, dug, difficulty, and pneo, to breath e).—Di ffic u ty of breathing attends many affections of respira tory organs, and occurs in very varied degree. It may amount to mere increased rapidity of breathing and shortness of breath on the slightest exertion, owing to general feebleness, as in anaemia, or to disease of the heart, or chronic disease of the lung, and may produce little dis comfort. More than this it may be, up to that degree in which breathing is a constant struggle, agonizing almost in its character, when every muscle that can possibly aid in drawing air into the lungs is called into play, nostrils working, muscles of neck straining, and chest heaving, the lower part being frequently sucked in. In children the movement of the nostrils is often the first indication of some interference with easy breathing, and later excessive heaving of the belly and sucking in of the lower ribs be come marked. Accompanying the severe forms of dyspncea are indications of the want of proper aeration of the blood, lividity of the surface of the body, blueness of finger nails, coldness of the extremities ; and when the struggle is severe the perspiration stands in beads or streams down the face. When the difficulty is considerable and lasting, without being so extreme, the want of proper purification of the blood produces head ache, languor, and dulness. In asthma (p. 366) the difficulty of breathing comes on in spasms, is-often excessively severe, seeming to threaten suffocation, and gradually passes off after a time.