课件：新型伤口敷料的特性与应用.ppt

Silver dressings as well as other antibacterial products should only be used in the critically colonised or infected wounds thus during a limited period of time in the wound healing process. What are the drawbacks when overusing silver dressings? Firstly, by using these dressings during the entire wound healing process we risk to develop resistance to silver. There is one reported case. Overuse may speed up resistance development. Silver has been shown in in vitro assays to be toxic to fibroblasts and keratinocytes. In severely burnt patients silver toxicity has been rarely reported and in these cases there has been an overdose of silver i.e. more than 10 grams have been taken up systemically. Argyria is a systemic effect but not toxic (to be explained further). Silver has been recognized to cause some, although not strong allergic reactions. Certain dressings may not be ideal in the granulation and maturation phases for example Acticoat has been reported to stick to the wound There is a risk of argyria , which is an irreversible (staining) discoloration of the skin. It is not dangerous but cosmetically not aesthetic. The risk for argyria is considered small however temporary discolouration of the skin when using silver products is quite common. Cost, as silver products in general are more costly than the advanced wound dressings they should only be used when it is clinically appropriate. Baer,W.S. The treatment of chronic osteomyelitis with the maggots (larva of the blowfly). J bone Joint surg 1931h 在英国用得少，新加坡不用，由于价格贵，使用不方便；用于非常深入，外科和化学方式不能到达的伤口 Healing: Superficial wounds (hair follicles and sweat glands are not completely destroyed). Will heal by re-epithelialization. High levels of sero/sanguinous fluid initially Wound typically dries out after 4-5 days. Site typically heals within 7-20 days (secondary intention) Exposure of nerve endings causes stinging/burning pain Site typically is dry and itchy after healing. ? Ideal dressing: Retains moisture and warmth