Dynamics of Wound Healing

by | Oct 24, 2021 | Blog

For the past three posts, we took a comprehensive look at wounds. We explored skin structure and its various functions; we identified different wounds based on their classification and types and we assessed wounds based on their characteristics. Today we will look at the dynamics of wound healing. If you have not read any of the previous blogs, be sure to do so before reading this one so you will get a better understanding of what is being discussed.

As usual, the information in this blog should not be taken as medical advice; always consult your doctor concerning the treatment of any medical issues.

Understanding how a wound heals may help you identify if there are problems with a wound. Once you know the good, you can identify the bad and get assistance from a doctor as soon as possible. You may take for granted a serious situation if you do not know what a serious situation concerning wounds looks like. This is the purpose of these blogs. To empower you with the knowledge to better help your elderly loved ones, and maybe even yourself one day. First, we will look at the types of wound healing, then the phases of wound healing, and finally the effects of aging on wound healing.

Types of Wound Healing

Any break in the skin is considered a wound. Since the skin is the body’s first line of defense, a wound must heal otherwise it may become an open door for foreign bodies to enter the body and cause harm. There are three (3) types of wound healing

Primary Intention Healing 

In these wounds, usually, there is no loss of tissue. Usually, the broken skin is superficial and not very deep. Wounds that heal like this are, for example, surgical wounds, abrasions, and sunburn (check out the blog http://niceusgeriatric.com/2021/10/03/all-about-wounds-part-two-of-a-four-part-series/ to learn more about types of wounds)

Secondary Intention Healing

A wound that involves some amount of tissue loss may heal in this manner. They take longer to heal as compared to primary intention and have a higher rate of complications. There is more depth to these wounds. They have a gap to be filled – (the filling process is called granulation) and may leave a scar. Some types of wounds in this category are pressure ulcers and lacerations.

Tertiary Intention Healing

Some wounds that also have a gap to be filled are left open for several days to first treat an infection or allow exudate (inflammation) to drain. The wound healing is delayed. These wounds heal in three (3) steps – draining, filling by granulation, and then suturing. A wound that does not heal under secondary intention may become infected and need tertiary intention healing.

Even though there are different types of wound healing, all wounds heal in the same step-by-step process. The actual healing itself follows four phases, regardless of the size of the wound or how the wound was caused in the first place. Let’s take a look at these four phases.

PHASE 1 – Hemostasis

When tissue is damaged, causing a wound, certain chemicals and blood from the injured blood vessels fill the area. Blood platelets form a clot and fibrin in the clot binds the wound edges together.

PHASE 2 – Inflammation

The inflammatory response is triggered, making the capillary (small blood vessels) leaky. The edges of the wound swell, white blood cells come in and destroy any bacteria but also destroy the clot formed in phase 1. Because of this, there is redness, swelling, warmth, pain and even loss of function may occur.

PHASE 3- Proliferation

Neighboring healthy tissue supplies the wound with blood, nutrients, and other important elements needed to form a soft, pink, and highly vascular (a lot of blood vessels) granulation tissue, which builds up the area.

PHASE 4- Maturation

Special cells called Fibroblasts in the granulation tissue (mentioned in Phase 3) secrete a substance called collagen, which is a glue-like substance. Collagen serves to form scar tissue in the area. The wound completes the healing process with epithelial cells that form a new layer and replace the layer that was destroyed to form the wound in the first place. Damaged tissue regenerates and the scar diminishes in size. In some persons, the scar may get larger or hypertrophy, leading to a keloid.

Although this is the “textbook” process, many wounds do not heal in this strict order. Typically, the phases of wound healing overlap.

There are hindrances to healing and one of those is aging. The effects of aging on wound healing are usually due to the decreased functionality of skin with age.

Factors that delay healing in the elderly

  • Skin cells don’t regenerate fast enough, delaying healing
  • Poor oxygenation of the wound as blood vessels are fragile
  • Impaired function of the respiratory or immune system (oxygen is needed for healthy tissue to develop and the immune system gives the inflammatory response needed in the healing process- mentioned earlier)
  • Reduced thickness of the skin, so the skin itself maybe prone to Pressure Ulcers – easier to get a wound
  • The tissue that heals the wound is not as strong so its easier to get re-injured on the same wound.

Factors that complicate healing in the elderly.

  • Poor nutrition and hydration – and this can be caused by loose dentures, pain in the mouth, not having help to cook a nutritious meal for them, not having enough money to buy healthy foods or not remembering to drink enough water
  • Presence of a chronic disease (such as diabetes)
  • Use of multiple medications – they may have side effects that complicate the healing process

This brings us to the end of our series All About Wound Care. The hope is that you can use this knowledge to better identify, recognize and act upon a serious wound that may cause a lot of harm to your elderly loved one if left unattended. In another blog, we will focus solely on Pressure Ulcers and how to prevent them in bed-ridden persons. As always, thank you for reading and share with someone who may benefit from this knowledge.

Photo by Sharon McCutcheon on Unsplash