COMPRESSION. 63 



dangerous, from the complications of concussion, compression, ex- 

 travasation of blood, and inflammation. Tiie treatment consists in 

 removing the cause of compression, and combating the effects of 

 inflammation ; the former by the operation of trephining, and the 

 latter by strict antiphlogistic means. 



COMPRESSION. 



Compression may be the result of extravasated blood, depression 

 of the bone, or the formation of pus. The symptoms which cha- 

 racterize it are slow, laborious, stertorous respiration ; a full, regular, 

 slow pluse, and complete loss of consciousness and sensibility ; the 

 muscles are relaxed and powerless, pupils dilated and insensible, the 

 skin warm and moist, and the sphincters often relaxed. The 

 patient may perish immediately from coma, or may rapidly recover 

 from the removal of the cause of depression. 



Extravasation of blood may take place immediately upon the 

 infliction of the injury, or not until reaction has followed ; concus- 

 sion often being produced at the same time. The extravasation 

 may be situated between the bone and the dura mater, which is the 

 result of a wound of the meningeal artery. This may be the result 

 either of a direct blow, or of a counter stroke. The symptoms 

 gradually appear, and if urgent, the trephine should be used, and 

 the blood, if fluid, escapes at once. If the symptoms be not severe, 

 the clot may be absorbed, and the brain gradually recover from the 

 compression, provided high inflammatory action is prevented. 



Blood may be effused within the membranes, or within the ventri- 

 cles; most frequently being the result of injury to the vessels of the 

 pia mater. The clot effused within the membranes is usually larger, 

 and will produce more dangerous symptoms than one external to 

 them. The most dangerous consequences result from a clot at the 

 base of the brain. 



Treatynent. — The objects are to prevent increased effusion and 

 diminish subsequent inflammation, and the removal of the clot. The 

 head should be elevated, cups and cold applications applied, with 

 general bloodletting and purging. The action of the heart is to be 

 diminished, in order to prevent the further extravasation of blood. 

 The removal of the clot is accomplished by trephining, and opening 

 the membranes. If, however, the clot is at the base of the cranium, 

 or it is uncertain where it may be, the membranes are not to be 

 opened, for the chances of inflammation would be much increased 

 by the operation, and the cause of compression not certainly 

 removed. 



Compression resulting from the formation of pus, does not exhi- 

 bit the ordinary symptoms rapidly, as is the case by the escape of 

 blood, nor do the symptoms subside so readily; because pus is not 

 so amenable to absorption as blood. It cannot be discharged but by 



