Wound Care: Basics Concepts and Treatments

The following course is an edited transcript of the live course Wound Care: Basic Concepts and Treatment by Jennifer A. Gardner, PT, DPT, MHA, CWS.  

PTs and Wound Care

So, the question I get asked frequently is, since when do PTs do wound care? I always get asked that question. Why are you, as a PT, doing wound care? Or, you're no longer a PT because you do wound care now. I have to explain to people that wound care or integumentary, is one of our four practice patterns. The integumentary system is not an area that people typically associate with physical therapy. Usually, they think of neuromuscular or musculoskeletal disorders as what PTs treat, not wound care. The Wound Care Special Interest Group of the Academy on Clinical Electrophysiology and Wound Management is very active in wound care and encouraging physical therapists to be active in wound care. Currently, we do not have a certification just for wound care in the American Physical Therapy Association so we have to go through other organizations, such as the American Board of Wound Management if we want to become certified. We are working on the development of a certification so that it will be something similar to a certification in neuro, orthopedics, pediatrics, et cetera.  We will be going through basic wound care and some basic dressings and treatment options today. Even if you don't choose to specialize in wound care, it's important to have a basic understanding. For example, you may see someone in an outpatient setting who has a non-healing incision after a total knee or a total hip replacement and you may be the first person to identify that there is a problem with the wound healing. If you're in a rehab, or acute care, or long-term care setting, you may have patients with pressure injuries or other types of wounds that, again, you might not be the individual taking care of those wounds, but you need to be able to identify them and give other members of the healthcare team the heads up that those wounds are present. This course will serve as a basic introduction.

Types of Wound Healing

Primary Intention Healing

Primary intention is when a person has a suture, or perhaps a laceration, and the wound is closed by sutures, staples, et cetera. The wound doesn't have to granulate or fill in by granulation tissue and it doesn't have to re-epithelialize. The wound edges are pulled together and closed by the sutures or staples. Rarely do wound care specialists have to deal with this type of wound unless for whatever reason it opens up.

Tertiary Intention Healing

Tertiary, or delayed primary healing is when a surgeon will leave the wound open to granulate prior to closing it with sutures or staples.  A lot of times we see this tertiary intention when there's an infection expected or suspected, or if there's a traumatic injury such as a person riding a motorcycle who slid and has some road rash and deeper lacerations. There may be some fear that gravel or debris is in the wound, so the doctor will leave the wound open to granulate and heal a little bit before they close it primarily.

Secondary Intention Healing

Secondary intention, also called full thickness healing, is where we will concentrate the most today. These are the wounds that have to heal by granulation and re-epithelialization.

Full thickness, or secondary intention healing, is the most effective form of healing when a wound goes through all layers of skin and/or into the underlying tissues. If a doctor tries to prematurely close a wound (prior to full granulation process occurring) that has some significant depth to it, then the patient may become susceptible to an abscess. I like to use the analogy of gardening or planting trees.  You can't just dig a hole, and then cover it over with grass, or cover it over with mulch, without allowing that hole to be filled in with dirt first. The same thing is applicable regarding a wound. The wound needs to be filled in with granulation tissue first before you can close it with epithelialization.

Full thickness wounds heal by formation of granulation tissue, and contraction of the wound edges. They will have scar tissue formation and the tissue will not be the same tissue that it was prior to the injury. It is important that patients' understand that their wounds, even though they appear healed once they're fully closed, that they're still only 80% as strong as the tissue that was present there before. The patients need to understand that they will always be prone to a future breakdown in that same area. So, when patients have pressure injuries and/or diabetic foot ulcers, it's important that they understand, that even though they go on to heal, they're going to be at risk for future re-ulceration because the tissue strength is not as durable as it was before.

Wound Healing Physiology

When we look at wound healing, we like to think of it as a series of overlapping events. Typically they should occur in a reasonably predictive fashion. They should go through the first phase, which is inflammation and hemostasis, and then advance to proliferation, and finally, maturation. The problem occurs when a wound stays in one phase longer than we expected or that it just can't advance to the next stage for a number of different reasons. Whether a patient's wound is an acute wound or a chronic wound, that healing cascade should be the same. The difference is an acute wound will move through the phases much quicker and we will get healing in a quicker time than we will with chronic wounds. Hopefully, with good wound care, we are able to move these chronic wounds through these phases in a reasonable fashion as well. So, as I mentioned, there are three phases of wound healing, though some books might say there are four. This is because sometimes they will combine inflammation with hemostasis, or they'll make hemostasis the first phase of wound healing and then inflammation the second phase. It's not really important to know whether there's three or four, but understand that there are different phases and that wounds need to go in a reasonable, orderly fashion through these phases.

Inflammation/Hemostasis

The first thing that happens when there is an injury is hemostasis has to occur. This is the initial reaction after the wound happens. It occurs to stop the bleeding and prevent further injury. Once the bleeding has been stopped, then the inflammatory process begins. Once inflammation ramps up to get rid of the necrotic tissue, and gets rid of any bacteria that might be in the wound, then the proliferation phase can move in. The proliferation stage is where we'll get the granulation, the re-epithelialization, and the wound closure. And then the final phase is that maturation phase, where that collagen starts to remodel, and the scar becomes stronger.

Figure 1 is a diagram of the phases of tissue repair. And as you can see, these phases do not occur by themselves, but they occur overlapping and they occur simultaneously. So sometimes even though inflammation begins in the first few minutes, or hours, or days of the wound or the injury, the second phase will start while the inflammatory phase is still going on. The wound in the remodeling phase will start while the granulation tissue phase is still going on as well. That is normal and what we expect to happen. Hopefully, we can have most wounds heal within that 30 day period. The dotted line is in Figure 1 is showing that that collagen accumulation and remodeling continues to occur even after the wound is healed, which can take up to two years before that scar is fully mature. Again, it is important, to remind your patients that even though their wound looks healed, they still need it to continue to mature and strengthen in that final phase of wound healing.