When extravasation has already taken place, massage is the most speedy and efficacious means of dispersing the effused blood.  The part should be massaged several times a day, unless the presence of blebs or abrasions of the skin prevents this being done.  When this is the case, the use of antiseptic dressings is called for to prevent infection and to promote healing, after which massage is employed.

When the tension caused by the extravasated blood threatens the vitality of the skin, incisions may be made, if asepsis can be assured.  The blood from a haematoma may be withdrawn by an exploring needle, and the puncture sealed with collodion.  Infective complications must be looked for and dealt with on general principles.

WOUNDS

A wound is a solution in the continuity of the skin or mucous membrane and of the underlying tissues, caused by violence.

Three varieties of wounds are described:  incised, punctured, and contused and lacerated.

#Incised Wounds.#—­Typical examples of incised wounds are those made by the surgeon in the course of an operation, wounds accidentally inflicted by cutting instruments, and suicidal cut-throat wounds.  It should be borne in mind in connection with medico-legal inquiries, that wounds of soft parts that closely overlie a bone, such as the skull, the tibia, or the patella, although, inflicted by a blunt instrument, may have all the appearances of incised wounds.

Clinical Features.—­One of the characteristic features of an incised wound is its tendency to gape.  This is evident in long skin wounds, and especially when the cut runs across the part, or when it extends deeply enough to divide muscular fibres at right angles to their long axis.  The gaping of a wound, further, is more marked when the underlying tissues are in a state of tension—­as, for example, in inflamed parts.  Incised wounds in the palm of the hand, the sole of the foot, or the scalp, however, have little tendency to gape, because of the close attachment of the skin to the underlying fascia.

Incised wounds, especially in inflamed tissues, tend to bleed profusely; and when a vessel is only partly divided and is therefore unable to contract, it continues to bleed longer than when completely cut across.

The special risks of incised wounds are:  (1) division of large blood vessels, leading to profuse haemorrhage; (2) division of nerve-trunks, resulting in motor and sensory disturbances; and (3) division of tendons or muscles, interfering with movement.