In the management of wounds and other surgical conditions it is necessary to eliminate various extraneous influences which tend to delay or arrest the natural process of repair.
Of these, one of the most important is undue movement of the affected part. “The first and great requisite for the restoration of injured parts is rest,” said John Hunter; and physiological and mechanical rest as the chief of natural therapeutic agents was the theme of John Hilton's classical work—Rest and Pain. In this connection it must be understood that “rest” implies more than the mere state of physical repose: all physiological as well as mechanical function must be prevented as far as is possible. For instance, the constituent bones of a joint affected with tuberculosis must be controlled by splints or other appliances so that no movement can take place between them, and the limb may not be used for any purpose; physiological rest may be secured to an inflamed colon by making an artificial anus in the cæcum; the activity of a diseased kidney may be diminished by regulating the quantity and quality of the fluids taken by the patient.
Another source of interference with repair in wounds is irritation, either by mechanical agents such as rough, unsuitable dressings, bandages, or ill-fitting splints; or by chemical agents in the form of strong lotions or other applications.
An unhealthy or devitalised condition of the patient's tissues also hinders the reparative process. Bruised or lacerated skin heals less kindly than skin cut with a smooth, sharp instrument; and persistent venous congestion of a part, such as occurs, for example, in the leg when the veins are varicose, by preventing the access of healthy blood, tends to delay the healing of open wounds. The existence of grave constitutional disease, such as Bright's disease, diabetes, syphilis, scurvy, or alcoholism, also impedes healing.
Infection by disease-producing micro-organisms or pathogenic bacteria is, however, the most potent factor in disturbing the natural process of repair in wounds.