Bandages and topical agents.

Bandages are included in the regimen of therapy of superficial wounds. Bandages have varying functions depending upon the type of wound to which they are applied. When bandaging recently inflicted open wounds, the primary bandage layer may be dry-to-dry, wet-to-dry, or wet-to-wet, depending upon the type of tissue and exudate present on the wound. These bandages aid in debriding and cleansing a wound. The secondary layer of such bandages serves primarily to absorb material from the wound, and the tertiary bandage layer serves to hold the other bandage layers in place. Once an open wound is well into the repair stage of healing, an occlusive bandage may be considered to help enhance epithelialization of the wound. Bandages for wounds associated with compound fractures must include some form of fixation for the fracture. Other types of bandages are designed to (1) cover closed wounds, (2) provide pressure over a wound, and (3) relieve pressure over wounds or impending wounds. Bandages for closed wounds provide protection and allow for absorption of exudate that may be present. Pressure bandages are used to control minor hemorrhage, edema, and excess granulation tissue. With impending decubital ulcers, actual decubital ulcers, or repaired decubital ulcers, it is necessary to have a bandage designed to relieve pressure over the lesion. Many substances have been described for topical application to wounds. This section presents information on some substances available to or commonly used by veterinarians. It includes information on the wound lavage solutions chlorhexidine diacetate, povidone-iodine, hydrogen peroxide, and sodium hypochlorite solutions. Topical antibacterial agents are used to help prevent wound infection. The triple antibiotics, silver sulfadiazine, nitrofurazones, and gentamicin sulfate are some commonly used antibacterial agents. Hydrophilic agents are used to diffuse fluids through the wound tissues to bathe the tissues from the inside. Dry starch copolymer flakes and dextran polymer beads are two substances that help bathe the wound with the body's own fluids. Other topical medications are used to selectively act upon various wound tissues and exudates to aid in cleansing the wound; these include organic acid preparations and enzymatic debriding agents. In addition, a live yeast-cell derivative has been described for enhancing tissue oxygen consumption, epithelialization, and collagen synthesis in wounds.