482 PROGNOSIS AND TREATMENT OF THORACIC INJURIES. 



production. This may suffice to indicate whether the chest-wall 

 has been penetrated. 



(2) The breathing must be watched. Dyspnoea may be the 

 result of pneumothorax, hemothorax, or pleurisy, and occasionally 

 in less degree, of injury to the muscles of respiration. Septic pleuritis 

 is associated with high fever. Percussion determines the existence 

 both of pneumothorax and of hemothorax, and allows of their being 

 distinguished. 



(3) Blood-stained discharge from the nose or mouth generally 

 points to injury of the lung, though its absence does not establish 

 the contrary. 



(4) The passage of air through the wound during breathing is 

 strong evidence of a penetrating wound of the chest ; but, as above 

 stated, entrance of air or emphysema of neighbouring parts, occurs 

 in some non-penetrating wounds of large extent. 



(5) Pulmonary prolapse sometimes occurs after large openings 

 in the thoracic wall, and the piece of lung is liable to be strangulated 

 and become necrotic. 



(6) If these observations do not determine whether the wound 

 is a penetrating one, and it is considered absolutely necessary to 

 determine the question rather than to leave it uncertain and merely 

 to adopt the treatment usual in penetrating wounds, the parts may 

 be disinfected, and further examined with the aseptic finger or probe. 

 In default of an accurate diagnosis, it is, however, better to adopt 

 the treatment for a penetrating wound. Bleeding vessels should 

 be ligatured, and any fragments of broken ribs removed under 

 antiseptic precautions. 



Animals with such wounds sometimes bend the hind-quarters 

 instinctively towards the injured side, and thus prevent the wound 

 gaping. 



Prognosis. Every penetrating wound of the chest should be 

 viewed as a possibly fatal injury ; infection is almost inevitable, 

 but all do not necessarily take a fatal course. They are more grave 

 in horses than in cattle, but less so in carnivora. The prognosis 

 chiefly depends on whether or not infection exists with pneumothorax 

 or haemothorax, and pleurisy seems imminent. According to general 

 experience, the risk of pleurisy is greatest in horses. When thoracic 

 wounds are of a serious character, most horses require to be sup- 

 ported in slings, otherwise they sometimes die in two or three days 

 Incised wounds produced by scythes or lances heal more easily than 

 penetrating bruised wounds made by manure-forks or the tines of 

 harrows. Complications materially affect prognosis ; pneumothorax, 



