484 RESPIRATION 



against the sides of the thorax and epigastric region. This procedure 

 may also be followed if the patient is placed in the supine position with 

 his arms resting against the sides of his body. A method, which is 

 commonly employed in the resuscitation of animals is the following: 

 The body is raised free from the floor by the hind limbs. The mouth 

 is opened and the tongue pulled out synchronously with the compression 

 of the thorax which is effected by placing the flat hands from behind 

 upon the sides of the lower part of the chest. Schafer 1 suggests that 

 the patient be placed in the prone posture, a heavy garment being 

 placed underneath his chest and epigastrium. The operator assumes 

 a kneeling position beside the legs of the patient and, bending forward, 

 rests his flat hands against the sides of the lower part of the thorax, 

 so that the tips of his thumbs come to lie close to the vertebral column. 

 By gradually permitting his weight to be supported by his arms, the 

 chest is pressed upon and air is forced out of the lungs. On releasing 

 this pressure, the parts return into their original positions and cause 

 the air to flow in. 



The methods which purpose to distend the lungs with air held under 

 pressure, are most commonly employed in long-continued experiments 

 upon animals, but may also be used in resuscitating human beings. 

 Thus, the expansion of the lungs of the new-born may be frequently 

 facilitated by blowing air into these organs, the mouth of the operator 

 being placed against that of the infant. In the laboratory, it is cus- 

 tomary to expose the trachea of the animal and to insert in it a rectangu- 

 lar cannula which in turn is connected with a pair of bellows. In 

 experiments of longer duration it is advantageous to employ a power 

 pump which it is possible to regulate in such a way that a different 

 rate and amplitude of respiration may be obtained within a few mo- 

 ments. The deflation of the lungs may be greatly hastened by the 

 withdrawal of the air by slight suction. 2 



This principle is made use of in the construction of the so-called 

 pulmotor or lungmotor, 3 a small force-pump intended to be employed 

 upon human beings. It is worked by hand and possesses safeguards 

 .in the form of adjustable valves. It may readily be surmised that the 

 method of inflation through the mouth cannot present any unusual 

 difficulties in unconscious persons, but is not easily executed when 

 consciousness has again been established, because the current of air 

 is then strongly opposed by the voluntary muscles in the region of 

 the glottis, and may in.addition be counteracted by those of the thorax. 

 By endeavoring to overcome this resistance serious injury may be in- 

 flicted upon the lung tissue, but the conscious subject may overcome 

 these reflexes by remaining passive and by making inspiratory move- 

 ments in unison with the ingoing blast of air. Tracheotomy obviates 



1 Jour, of the Amer. Med. Assoc., li, 1908, 801. 



2 A most satisfactory respiration machine has been described by Hoyt, Jour, 

 of Physiol., xxvii, 1901, 48. 



3 Henderson, Jour. Am. Med. Assoc., Ixvii, 1916, 1. 



