2 Germain Sée in Nouveau Dictionnaire de Médecine et de Chirurgie, tome iii. p. 617, Paris, 1865.
The patient, experiencing an urgent desire for breath, instinctively places himself in the position most favorable for the ready admission of air into the lungs. If in bed he sits up, and, resting on his hands or grasping his knees with them, he so fixes the body that the muscles of respiration may work to the greatest advantage. The shoulders are drawn up and the head thrown back. The expression of the face is one of great anxiety—pale at first, then red, and as the attack increases in severity assumes a dusky, bluish tint; the mouth is partially opened, the nostrils are dilated; the eyes, the conjunctivæ of which are much injected, are prominent, with a wild, staring look; and the forehead is moist with perspiration. Others in their desperate struggle for breath spring from the bed, throw open the window, and, regardless of everything save what they believe to be impending suffocation, recklessly gasp in the cold night air. Sometimes the sufferer prefers to kneel before a table or some other article of furniture, supporting his head with his hands. Whatever posture he assumes, he is actuated by the one impulse of placing himself in the position that will enable him to use to the greatest advantage the muscles of respiration and their auxiliaries. The sterno-cleido-mastoid muscles are contracted to the utmost, and, projecting like hard cords, with the aid of other muscles draw the chest upward. The patient instinctively avoids every unnecessary exertion as having a tendency to aggravate his dyspnoea; he speaks but little, and when questioned usually replies with a motion of the head.
In ordinary respiration the inspiratory movement is twice as long as the expirium, the latter, except in forced expiration, being a purely passive act. In asthma this rule is reversed, the expiratory movement being four or five times as long as the inspirium, and is often so slow that it fills the whole of the pause which usually intervenes between the completion of one respiration and the beginning of another. It is sometimes so slow "that it seems as though the lung would never empty itself." In the desperate struggle for breath the respiratory muscles are exerted to the utmost in futile endeavors to expand the chest; with each inspiration there is an elongation of the thorax, but no lateral movement. The chest moves up and down, but there is no expansion; "the muscles tug at the ribs, but the ribs refuse to rise" (Salter), the walls of the chest remaining immovable.
Notwithstanding the all but tetanic contraction of the diaphragm, there is during each inspiration a sinking in of the epigastrium, and in severe cases also of the spaces above and below the clavicles. During expiration the abdominal muscles, especially the recti, are hard and tense, the pressure thus exerted being sometimes sufficient to expel the contents of the lower bowel and bladder.3 The transversus is also tightly contracted, and a cross furrow above the umbilicus indicates that the contraction of its upper half is opposed to the contents of the abdomen forced down by the distended lung (Biermer). Although the dyspnoea is great, there is no increase in the frequency of the respirations so long as the patient remains quiet, but, on the contrary, they are often less frequent than in health. This slowing of the respiration is also observed in the dyspnoea from laryngeal stenosis in croup, etc.; but in these cases we do not have the prolonged expiration which is so characteristic of asthma (Biermer). At every breath which the patient takes there is a peculiar wheezing sound which may be heard distinctly all over the room; it is usually heard only during expiration, but some authors (Biermer) claim that it is also audible during inspiration.
3 Bamberger's case, as quoted by Riegel, Ziemssen's Pathologie u. Therapie, Leipzig, 1875, Band iv. 2, S. 282.
On auscultating the chest it will be found that the ordinary vesicular murmur is either entirely absent, or if heard it is only over very limited areas. In the place of it we have an endless and ever-changing variety of dry sounds, such as whistling, cooing, mewing, snoring, etc., technically styled sibilant or sonorous ronchi. They are usually equally diffused over both lungs, but are sometimes confined to one. The sibilant râles afford an index of the degree of spasm, being in mild cases equally audible during both inspiration and expiration, while in severe attacks they are louder during expiration (Biermer). That the vesicular murmur cannot be heard is due not only to its being masked by the louder ronchi, but also to the absence of the condition necessary for its production, the spasmodic constriction of the bronchial tubes or their plugging with tough, viscid mucus preventing the entrance of sufficient air to produce the sound. Sometimes a hitherto occluded tube becomes pervious, and we have vesicular respiration where a moment before only dry sibilant râles were heard. Usually at the close of the attack, when cough sets in, there are occasional moist râles. These become more frequent as the expectoration becomes more abundant. Frequently, however, the paroxysm terminates much more abruptly, the spasm relaxes, and the air rushing through the tubes gives rise to puerile respiration.
During the paroxysm there is, even in the early stages of asthma, more or less distension of the lungs, measurement of the chest showing that its circumference is four to eight centimeters greater than before the attack (Beau). This transitory emphysema, which must not be confounded with that due to structural changes observed in old cases, disappears with the attack, and the lung returns to its normal condition. This distension causes the exaggerated resonance obtained by percussion which is one of the most constant symptoms. At the base of the lung, especially posteriorly and laterally, there is a peculiar modification of the percussion sound to which Biermer has applied the name Schachtelton, from its resemblance to the note produced by striking an empty pasteboard box. Besides this exaggerated resonance, it will be found that the line of dulness on the right side, which marks the upper border of the liver, is fully two inches lower during the paroxysm than before, and that the area of cardiac dulness is somewhat diminished by the overlapping of the distended lung-tissue (Riegel). Another peculiarity elicited by percussion, and to which Bamberger was the first to direct attention, is that in some rare cases instead of moving vertically the line of hepatic dulness remains unchanged during both acts of respiration.
Toward the close of the attack the congested mucous membrane of the bronchi begins to secrete, and there is more or less cough. The matter expectorated consists at first of little balls of tough, semi-transparent mucus not much larger than a pea. It is exceedingly tenacious, and is raised with great difficulty. Examined under the microscope, the sputum is found to consist "of a great number of corpuscles, some of which are polyhedral in form with rounded angles; they are pale, homogeneous, and slightly granular. At first sight they resemble pus-corpuscles, but they are much larger, less circular in form, and have no nucleus. In addition to these corpuscles there are others which are oval, elongated, fusiform, and sometimes linear in shape, but all of them appear to be of the same nature and possess the same refracting power as the corpuscles first mentioned. They are all of them agglomerated in a sort of viscous matter."4 The expectoration often contains blood, and in some rare instances profuse hemorrhages have been known to occur. Sometimes the matter has particles of soot and coal-dust intermingled with it, the so-called carbonaceous sputum (Sée). In addition to the cells above described, the sputa contains small yellowish-green masses or threads in which are imbedded the peculiar octahedral crystals which Leyden has ingeniously connected with the etiology of asthma, and to which we shall again have occasion to refer.5 Ungar has recently also discovered crystals of oxalate of lime in the sputa.
4 Germain Sée, Nouveau Dictionnaire de Médecine et de Chirurgie, pp. 612, 613; also, Salter, Asthma, its Pathology and Treatment, Am. ed., p. 944.
5 Riegel, in Ziemssen's Handbuch d. Pathologie u. Therapie, vol. iv. 2, pp. 268, 285.