In a diffuse hemorrhage the coagulation of fibrin induces induration, the serum and leukocytes are absorbed, the red blood cells disintegrate, and the coloring matter is widely diffused by the tissue fluids, and hemoglobin is changed into hematoidin which crystallizes. In union with these chemical changes, color changes ensue, the part being at first red and then becoming purple, black, green, lemon and citron. The stain following a contusion is most marked in the most dependent area.
A hematoma acts as an irritant, inflammation ensues around it and it is encapsuled by embryonic tissue, which, by organizing into fibrous tissue, forms a blood cyst and gradually absorbs the fluid blood, the cysts contents becoming thicker and thicker. A fibrous scar may remain, and a blood clot, with very much indurated surrounding tissue, giving a hard edge, is noticed after bruises of the periosteum. If serum is not absorbed, hematoidin forms and the fluid becomes clear. A hematoma may suppurate, an abscess forming, but this rarely happens except in drunkards, although it occasionally occurs in persons who do not use alcohol.
Symptoms. The symptoms are tenderness, swelling, pain, and numbness. The pain may be severe, but rarely persists beyond the first twenty-four hours. Discoloration appears quickly in superficial contusions, but only after days, in deeper ones. Shock and loss of function are present only after severe contusions. The swelling is first due to blood and is soon added to by inflammatory exudation.
Terminations of Contusions. Slight contusions terminate promptly by resolution; the more severe may terminate in gangrene, inflammation, abscess, fibroid thickening, hypertrophy of the tissues involved, (as in the case of bone), chronic inflammations, and even malignant growths, particularly sarcomata.
Prognosis. The prognosis of contusions is a matter of every day importance, and it is sometimes extremely difficult to prognosticate accurately. The determining forces are principally the nature and violence of the contusing force, the tissues and organs involved, and the general condition of the patient. Even the injury of the tissues that may be easily inspected, such as the skin, may be much more severe than is apparent. In tissues of low vitality, such as synovial membrane, cartilage and ligaments of a joint, repair is proportionately delayed, whereas in highly vascular tissue it is more rapid. Contusions of tissues that cannot be given physiologic rest, such as the thoracic wall, and the respiratory muscles, respond less promptly to treatment.
The general condition of the patient is an important factor in the prognosis, the most favorable being vigorous adult life without organic disease. Among the unfavorable general states are, the extremities of life, the very anemic and the plethoric, the tuberculous, the syphilitic, the diabetic, and like diatheses, while in the rheumatic and the gouty, the slightest injury may be most persistent. The starved, the overfed, the over-worked, the fatigued, the alcoholic, and those exposed to extremes of heat and cold, are unfavorably affected.
Treatment. Slight bruises, favorably located, require no treatment. The arrest of hemorrhage, thereby diminishing the swelling, pain, and discoloration, is important. If the hemorrhage be from small vessels, elevation, rest, and the application of ice are sufficient. Frequently the application of pressure is indicated. Hemorrhage in deeper parts, such as that occurring under the fascia of the thigh, is sometimes best controlled by adhesive strapping. If the vessels are large and the hemorrhage is rapid, it is sometimes necessary to make a free incision and apply a ligature. Evaporating lotions or elastic pressure by bandaging over absorbent cotton, may assist. If the hemorrhage be in a joint causing immediate swelling, painful from distension, prompt aspiration will give relief. This should only be resorted to under the strictest aseptic precautions, as the conditions are favorable for microbic growth. If the soft parts are so severely contused as to jeopardize the nutrition, both bandaging and ice should be withheld, and in some instances even warm applications are advised. After the acute symptoms have passed, judicious massage may be most helpful in securing early resolution. Restoration of the vasomotor tone when impaired or lost may be greatly facilitated by douching with cold and hot water alternately followed by massage. During the acute stages, physiologic rest is important; the restoration of functional use in severe cases must be tentative, guided by the response of the tissue in the form of increased pain or swelling. These phenomena should be avoided if possible. If hematomata be not absorbed they should be aspirated and pressure applied before structural changes take place, such as the formation of a membrane. If the latter occurs and sufficient time has elapsed for the formation of definite new tissue, aspiration may be followed by the obliteration of the sac. Sometimes hematomata become so thoroughly and firmly organized and gradually increase in size, that it is extremely difficult to differentiate them from new growths. If pain and tenderness persist for a long time, particularly, if there be a predisposition to tuberculosis, especial care is necessary.
Treatment of Wounds in General. Arrest hemorrhage, bring about reaction, remove foreign bodies, asepticize, drain, coaptate the edges and dress, secure rest to the part and combat inflammation.
Constitutionally, allay pain, secure sleep, keep up the nutrition and treat inflammatory conditions.
Arrest of Hemorrhage. To arrest hemorrhage the bleeding point must be controlled by digital pressure until ready to be grasped with forceps; it is then caught up and tied with catgut or aseptic silk. Slight hemorrhage stops spontaneously on exposure to air, and moderate hemorrhage ceases after the vessels are clamped for a time; an injured vessel of some size must be ligated, even if it has ceased to bleed.