Overview
This lecture covers the phases of wound healing, types of wound closure (healing by intention), common complications, barriers to healing, and assessment of wound drainage and appearance.
Phases of Wound Healing
- Hemostasis is the first phase, aiming to stop bleeding via vasoconstriction, clotting, and platelet activation.
- The inflammatory phase allows neutrophils to enter the wound, causing swelling and pain as they fight infection.
- The proliferation phase generates new skin cells to fill and cover the wound.
- The maturation phase involves scar tissue remodeling, which can take over a year.
Types of Wound Healing (Healing by Intention)
- Primary intention: wound edges are well approximated and closed (e.g., surgical incisions, paper cuts).
- Secondary intention: wound heals from the inside out via granulation and epithelialization; longer healing time and higher infection risk (e.g., pressure injuries).
- Tertiary intention: wound closure is intentionally delayed for observation or debridement before surgical closure.
Complications and Barriers to Healing
- Dehiscence: previously closed wound reopens.
- Evisceration: wound reopens with organs protruding; medical emergency requiring saline-moistened gauze, lowering the head of the bed, and immediate provider notification.
- Chronic illnesses (e.g., diabetes mellitus) and poor glycemic control impair healing due to poor circulation.
- Immunosuppression from medications like corticosteroids also delays healing.
Wound Drainage and Appearance
- Serous drainage: clear, watery, and normal.
- Serosanguineous drainage: mix of serous fluid and blood, appears light pink.
- Sanguineous drainage: bright red and bloody.
- Purulent drainage: thick, cloudy, foul-smelling pus, indicates infection.
- Healthy wounds appear red and "beefy"; yellow wounds need cleaning; black wounds require debridement of dead tissue.
Key Terms & Definitions
- Hemostasis — stopping bleeding through vasoconstriction and clotting.
- Diapedesis — movement of neutrophils through capillary walls during inflammation.
- Dehiscence — reopening of a previously closed wound.
- Evisceration — wound opening with organs protruding.
- Granulation — new connective tissue and blood vessels formed during healing.
- Debridement — removal of dead or necrotic tissue.
Action Items / Next Steps
- Review diabetic foot care and wound care in next lecture/video.
- Maintain tight glycemic control in diabetic patients with wounds.
- Know emergency protocol for wound evisceration.