Paracentesis Pericardii 161 



that there might be pain on pressing the epigastrium ; there would 

 be also a prominence of the sternum and of the left costal cartilages, 

 especially in young subjects. If, as the patient lies in bed, the water- 

 tumour press against the trachea, the dyspnoea may be relieved by let- 

 ting him sit up, so that the fluid may be brought forwards. Pressure 

 on the oesophagus may cause dysphagia, especially when the patient is 

 lying down ; and by bulging against the right auricle and superior 

 vena cava it may produce fulness of the veins of face and neck, with, 

 possibly, oedema. 



In the treatment of acute pericarditis venassection and purgation 

 may be of great service by relieving the heart of some of its work. 



Paracentesis pericardii may be necessary when the pressure of 

 the fluid seriously interferes with the heart's action. 



The puncture may be performed in any part of the area of absolute 

 cardiac dulness, but the course of the internal mammary vessels at 

 half an inch from the border of the sternum must be remembered 

 (p. 156). The sternal end of the fourth or fifth space serves well. It 

 has been customary to operate on the left side, but I would urge that 

 the sternal end of the fourth right space is preferable, as the pericar- 

 dium is sure to be bulging there and the needle is less likely to 

 injure the heart. 



In suppurative pericarditis the abscess must be thoroughly evacu- 

 ated and the cavity washed out and drained, the incision being made, 

 layer by layer through the fourth or fifth intercostal space, to the 

 outer side of the line of the left internal mammary artery. When the 

 pericardium is reached it should be drawn well forwards so that the 

 pus and the irrigation-fluid may not escape into the anterior medias- 

 tinum. 



There is no definite sign by which adherence of the heart and peri- 

 cardium may be absolutely recognised, but in such cases the contract- 

 ing ventricles may be seen pulling-in the neighbouring intercostal 

 spaces, and even the lower end of the sternum and the adjacent car- 

 tilages. 



THE HEART 



The heart is, roughly, of the size of the closed fist of the individual ; 

 its weight averages 10 oz. It rests by its flat surface upon the dia- 

 phragm ; its base is directed upwards, backwards, and to the right, 

 opposite the four middle dor sal vertebra, and its apex points downwards 

 and to the left, beating against the fifth space. It lies behind the 

 lower two-thirds of the sternum, encroaching on the left side of the 

 thoracic cavity, and filling the space between the spine and the breast- 

 bone. 



The heart is free within the pericardium, and between the latter 

 and the chest-wall the pleurae and lungs intervene, only a small 

 triangular part of the heart being uncovered by lung during inspiration. 



M 



