ARTIFICIAL RESPIRATION. 757 



mouth is held open and the tongue (which would depress the epiglottis by falling 

 backward) is drawn forward. Artificial dilatation of the thorax can be effected 

 by stimulating the phrenic nerves at suitable intervals by means of sponge- 

 electrodes connected with an induction-apparatus. The electrodes are placed in 

 the situation of the anterior surface of the scalene muscle, irritation of which 

 will augment the inspiration. In desperate cases air may be blown directly into 

 the opened trachea through an elastic tube by means of a bellows or with the 

 mouth. Care, however, is required in this connection, in order to avoid injury to 

 the lungs. Artificial respiration has a vivifying effect through both the supply 

 of oxygen to, and the removal of carbon dioxid from, the blood ; therefore par- 

 ticularly favoring the movement of the blood in the heart and in the large vessels 

 of the thorax, and thus stimulating the circulation. If the action of the heart 

 has already ceased, resuscitation cannot be hoped for. In the case of asphyxiated 

 newborn children efforts at resuscitation should not be abandoned too early, that 

 is before cessation of the heart -beat, even if at first they appear hopeless, as the 

 medulla retains for a long time some measure of irritability. Pfluger and Zuntz 

 observed the reflex irritability and the heart-beat persist in the fetus for several 

 hours after death of the mother. In the case of resuscitated newborn children the 

 resuscitating measures should be suspended only after loud crying has taken place. 



Reference should be made here to the remarkable experiments of Bohm, who 

 succeeded by means of rhythmic compression of the heart in conjunction with 

 artificial respiration in resuscitating animals (cats) whose respiration and heart- 

 beat had ceased entirely for forty minutes in consequence of asphyxia or poisoning 

 with potassium-salts or chloroform and in which the carotid pressure had fallen. 

 The compression of the heart causes a slight movement of blood (much like a 

 feeble systole) ; at the same time the compression acts as a rhythmic stimulus 

 for the heart. The heart-beat returns first, then also the respiration. The resus- 

 citated heart-beat itself causes interchange of air. After restoration of breathing 

 reflex irritability also returns and gradually likewise voluntary movements. The 

 animals are blind for a few days, the brain torpid in function, the urine rich in 

 sugar. The experiments show the great importance, in the resuscitation of 

 asphyxiated individuals, of simultaneous action upon the heart. 



For physiological purposes artificial respiration is practised by blowing air by 

 means of a bellows into a tracheal cannula provided with a small lateral opening 

 for the escape of the expired air. If the animal is at the same time paralyzed by 

 curare it cannot be thrown into a state of disturbing restlessness in consequence 

 of independent and reflex movements of the musculature of the body. 



Pathological. If the lung is distended with air, it cannot be deprived of this 

 by direct compression, probably because in consequence of the direct pressure 

 affecting the lung the small bronchi are compressed before air can escape from 

 the pulmonary alveoli. If, however, a lung be filled with carbon dioxid instead 

 of air and if it be suspended under water, the carbon dioxid will be absorbed by 

 the water and the lung may thus become entirely airless (atelectatic). The 

 occurrence of atelectasis in certain portions of the lung in connection with disease 

 of this organ can be explained in this manner. If bronchi are occluded by mucus 

 or exudate, marked accumulation of carbon dioxid takes place in the related 

 pulmonary vesicles. This becomes the greater the more richly the blood in the 

 lungs (in consequence of the existing disease of the lung) is itself impregnated 

 with carbon dioxid. If, finally, the carbon dioxid is absorbed from the capillary 

 blood of the alveoli, or from the lymph, the affected pulmonary area may become 

 atelectatic. 



Among the pathological phenomena that are caused by abnormal (direct or 

 usually reflex) irritation of the respiratory center are spasm of the respiratory 

 muscles, inspiratory, expiratory or complex spasm; also attacks of diminished 

 respiratory frequency (spanipnea) or increased respiratory frequency (pyknopnea) 

 observed in neurotic individuals, together with dyspnea and a sense of fear. 



As the brain has relations to the respiratory movements the modification in 

 these movements in connection with cerebral disorders are readily explained. The 

 paralytic affections are, as a rule, upon the same side as the paralysis. Also 

 Cheyne-Stokes breathing is observed. 



