Wound Healing Flashcards
What is the Proliferation and Migration Phase?
Within 2 days after injury, endothelial cells from blood vessels near the edge of the necrotic tissue begin to proliferate. This is in order to begin a network that can transport oxygen and nutrients and support the healing tissue. (Angiogenesis).
This is visualized as granulation tissue! Which is mostly endothelial cells and fibroblasts.
Once tissue gaps are closed, a new matrix is built.
Collagen, elastin, and proteoglycan molecules, cross-link the collagen of the matrix and produce the initial scar
*Takes several weeks
What is the remodeling and maturation phase of wound healing?
The scar tissue is reduced and remodeled. Density of fibroblasts and capillaries declines by apoptosis or programmed cell death.
*Can take years
What is the strength of scars on the skin?
In the case of skin, a fully mature fibrous
scar requires 12 to 18 months to form and is about 20% to 30%
weaker than normal skin.
What is Primary Intention?
Healing by primary intention is the uniting of the edges of a wound, completing healing without granulation.
What is Secondary Intention?
Healing by secondary intention is wound closure in which the edges are separated, granulation tissue develops to fill the gap, and epithelium grows in over the granulations, producing a scar.
This occurs in a wound that cannot be closed.
What is Tertiary/Delayed Primary Intention?
Healing by tertiary intention is wound closure in which granulation tissue fills the gap between the edges of the wound, with epithelium growing over the granulation at a slower rate and producing a larger scar than results from healing from second intention. Suppuration is also usually found in tertiary wound closure.
This is when wound closure is delayed due to fear of infection.
It is often intentionally applied to lacerations that are not considered clean enough for immediate primary closure. The wound is left open for 5-10 days; then, it is sutured closed to decrease the risk of wound infection.
What is delayed primary intention?
Delayed primary closure is a combination of the aforementioned types of wound healing. It is often intentionally applied to lacerations that are not considered clean enough for immediate primary closure. The wound is left open for 5-10 days; then, it is sutured closed to decrease the risk of wound infection.
Keloid vs Hypertrophic Scars
Keloid:
Are commonly raised more than 4 mm from the skin’s surface
Lesions generally grow wider than the boundaries of a wound
May continue to grow over time
Are seen predominantly on the shoulders, cheeks, upper back, and chest
Appear after three months or so
Have a high recurrence rate after treatment
Hypertrophic:
Rarely become raised more than 4 mm above the skin
Are generally neater and cover only the wound circumference
Can develop anywhere on the body
Often fade somewhat over time
Appear within one month
Inflammatory Phase
is characterized by edema and drainage.
Treatment of Keloid Scars
Silicone gel has demonstrated some effectiveness in managing scars by applying the gel sheet directly over the actively maturing scar. Used alone, it can flatten the keloid. Silicone gel can be used along with a pressure dressing. A pressure dressing may be used for 12 to 18 months following a burn to promote a flat, pliable scar.
