Wound scabs are an evolutionary marvel, but are they the most efficient way to heal? Discover how moist wound healing can produce huge results for you and your patients.
Moist wound healing is a method of treatment in which the wound is kept in an optimally moist environment to promote cell growth and the formation of new skin tissue. While scabbed wounds generally do heal with time, keeping a wound moist can accelerate this process by nearly 50%. Not only that, but the resulting skin from moist wound healing can have a better cosmetic outcome, as the aqueous medium allows collagen fibres to align themselves more freely.
The role of exudate
The reason moist wound healing can be so effective is because the technique maintains an optimal level of exudate in contact with the wound at all times. Exudate is the moisture that naturally seeps out of a wound site, which serves not only as a vehicle for growth factors, hormones, and essential nutrients, but also as a medium for white blood cells to fight off infection and destroy invading foreign bodies. By keeping the right level of moisture, wounds can benefit from continuous 24-hour a day healing, improved cell growth, and even reduced pain, as the nerve endings on the skin are kept hydrated and bandages do not adhere when they are changed.
When dealing with exudate, it is vital to maintain a consistent amount to help autolytic debridement and optimize recovery time. Too little exudate and the wound will dry out. Too much and the surrounding skin can macerate, slowing down healing. That is why it is highly recommended to use a semipermeable foam dressing (see Figure 1) when there is a significant amount of exudate present. This type of dressing absorbs excess exudate, allowing moisture to evaporate out the back without drying out the wound. However, once a wound begins to produce less exudate, it is important to evaluate the wound to see if there is any further risk of infection. If there is, more honey dressings should be applied. If the risk is low, it is generally safe to switch to hydrogel. In either case, a foam dressing on a non-exudating wound can dry it out, so it is necessary to supplement the natural moisture with either honey or hydrogel (or both) to prevent the dressing from adhering.
Keeping the wound clean and moist
One of the most important factors in a comfortable and efficient healing process is keeping the wound clean and sufficiently moist, and a very effective natural solution for this is honey. First used in wound healing in 1500 BC by the Ancient Egyptians and Greeks, honey has several unique characteristics that make it ideal for staving off infection. The pH of honey creates the desired acidic environment to decrease bacterial growth, while also increasing fibroblast activity and the release of oxygen. Honey is also highly osmotic, meaning it draws fluid and lymph from underlying tissues, thus providing nourishment for the healing wound. Further, the Glucose Oxidase in honey converts to Hydrogen Peroxide and gluconic acid while in contact with the exudate from the wound. At low levels, this hydrogen peroxide offers antibacterial benefits, while also promoting angiogenesis and fibroblast activity.
Of the varieties of honey available around the world, New Zealand’s “Manuka” honey is one of the most well known for its excellent anti-microbial action. In addition to the regular wound healing benefits of honey, Manuka honey actually continues to produce Hydrogen Peroxide for much longer than other varieties. This is because regular honey naturally breaks down faster and is also often pasteurized, wherein the heat largely diminishes the Glucose Oxidase effect. 100% Medical Grade Manuka Honey is Gamma sterilized to keep the Glucose Oxidase active as long as possible. In addition, Manuka honey is also the only type of honey to contain MGO Methylgluoxal, which itself has powerful anti-bacterial properties. Even once the Hydrogen Peroxide is gone, the MGO continues to protect and heal the wound.
Choosing your moist wound healing approach
As in most cases in veterinary medicine, your approach to employing a moist wound healing technique is highly dependent on the case. A wound that is exudating heavily may require a highly absorbent dressing to remove some moisture and prevent maceration of the surrounding skin, whereas a wound displaying healthy granulation without much exudate may benefit more from a non-adherent dressing impregnated with honey or hydrogel. To know when to switch from the antibacterial honey to the moisturizing hydrogel, here’s a helpful rule of thumb: for yellow wounds use yellow honey, for clean wounds use clear hydrogel!
To aid you in making the best choices for your animal patients, learn more about moist wound healing at kruuse.com. You may also want to refer to Maximizing Wound Management by Derek Knottenbelt, a well-renowned veterinary professor in wound management, which presents a flowchart for approaching different types of wounds and details the twelve main identifiable inhibiting factors that affect wounds.