1.1 Wound Care Today
Like all living species, humans have always been subjected to wounds of all types and severities, whether by accident, by disease, by consequence and even caused on purpose. From a young age, we are accustomed to seeing or getting minor wounds, and either leaving them to heal by themselves or administering basic medical care at home. A layman, having likely experienced multiple minor wounds himself in his lifetime, could perhaps describe a wound as being an injury, a tear, cut, or break in the skin surface. This could be with or without further damage to the underlying tissues and bones.
For a broader definition of a wound, it could be described as any form of damage or break in the continuity of a living tissue. The damage may be caused by physical/mechanical aggression, chemical aggression, or by radiation or thermal aggression. It may result in the wound being ‘open’ (with the skin being cut, torn, or broken), or ‘closed’ (where the injury occurs without an apparent break in the skin). It also includes wounds that are purposefully created under controlled conditions, such as during surgery. Thus, wounds come in all shapes and forms, from the minor cuts, bruises, grazes and burns, to complex ‘dirty’ wounds where tissue has been randomly torn or damaged and exposed to an unfavourable environment.
Under normal, healthy and clean conditions, most minor wounds should heal by themselves, and need little attention. The body naturally engages into various stages of wound healing as soon as it becomes aware of an injury: (1) haemostasis, (2) inflammation, (3) proliferation and (4) remodelling/maturation. When there is any breach in tissue continuity, blood vessels and capillaries, haemostasis starts via several mechanisms which lead to the coagulation of blood, and fibrin and clot formation at the site of injury. Inflammation, which starts in parallel and continues for longer, is noticeable by swelling, redness and pain. It is caused by blood vessels releasing fluids, which among other things contain neutrophils and macrophages, to help get rid of damaged cells, debris and pathogens. The inflammation phase reduces when new and living cells begin to accumulate at the site. The third stage, proliferation then occurs, with the formation of new granulation tissue from the base of the wound to replace the original clot. This granulation tissue eventually completely covers the wound area with its mix of connective tissues made of collagen, extracellular matrix and microscopic blood vessels. Towards the end of the proliferation phase, re-epithelialisation occurs to resurface the wound site and restore the skin’s barrier function. Finally, the last stage of remodelling or maturation starts when the previously formed granulation tissue, and the newly formed micro blood vessels are gradually degraded when no longer needed. The collagen is remodelled from the immature Type III to the mature Type I and is reorganised and crosslinked in a more orderly way and eventually the wound is fully closed.
While the above stages have been simplified for a basic understanding, the details and the multiple mechanisms within each stage are complex and may occur simultaneously. The process is also made more complicated when additional factors come into play, such as the age, nutritional status, or behaviour of the injured person, the size, depth and severity of the wound, the environmental conditions, the position of the wound, the medications being used, the presence of systemic diseases, etc. Naturally, the more complex the situation is, the more care is required to keep the wound protected and help it heal.
The primary objective of basic wound care is to get the wound to progress through the above normal stages and eventually safely close or heal. To help this process, it is now well understoo...
