Upon suffering a minor injury, you might have been told to let your open wound “breathe” or “air out.”
However, wound healing science says differently.
In 1962, Dr. George Winter made medical history by performing a simple experiment with live pigs. After creating wounds on their backs, he covered some of the injuries with impermeable polyethylene membrane dressings and left the rest open to the air. Since moisture could not escape through the dressings, hence the term “impermeable,” the covered wounds healed faster than the uncovered wounds.
The results of Winter’s experiment established a paradigm that clinicians still use to make medical decisions today.
Water comprises up to 60% of the adult male human body and around 55% of the female body. The body’s water levels are highest at the beginning of life, around 78% for newborns. The skin plays a key role in keeping that water inside the body. If the skin and deeper tissues are disrupted by an injury, cells that over dry in the air, or “desiccate”, will die. If moisture isn’t provided for exposed cells to swim through, they bury themselves into deeper tissues to find it.
Since Winter’s discovery, more research has shown that moisture-balanced wounds have reduced chances of infection, cause less pain, and result in less scarring. The general principle is to use absorbent dressings for overly wet wounds and wet dressings for overly dry wounds to achieve that balance. Overly dry wounds, as mentioned before, will desiccate. Overly wet wounds may compromise healthy skin on the wound edge through maceration, which causes the skin to become soggy and possibly lift off.
Healthcare professionals modify the dressings they use depending on the patient’s ability to heal, the goals of care, the presence of infection, and the patient’s underlying condition(s). Common dressing ingredients used today include medical honey, silver, water-based gels (hydrogels), seaweed (alginates), collagen, and hypochlorous acid.
Many people can get away with leaving minor wounds open to air. These wounds will dry out, scab over, and eventually heal on their own. However, many factors can delay wound healing for months or even years. If wound healing stalls out, dressings that provide moisture balance may not be enough. Common causes of delayed wound healing include diabetes, compromised circulation (especially in the lower limbs), malnourishment, critical illness, infection, and the dying process. These wounds require professional care that may involve managing or correcting internal medical issues, specialized therapies, medications, and even surgery.
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