Wound care principles

Phases of Healing - The Repair Crew

⭐ Collagen Cross-Talk: The transition from pliable Type III collagen (granulation tissue) to strong Type I collagen is critical for wound strength. Deficiencies in this process (e.g., vitamin C, copper) lead to poor healing and dehiscence.

Wound Classification - Sorting the Damage

• Class I (Clean):
  • Uninfected, no inflammation; tracts not entered.
  • Examples: Hernia repair, breast biopsy.
  • SSI Risk: <2%.
• Class II (Clean-Contaminated):
  • Respiratory, GI, or GU tracts entered under controlled conditions.
  • Examples: Elective cholecystectomy, lung resection.
  • SSI Risk: 3-5%.
• Class III (Contaminated):
  • Open, fresh accidental wounds or major sterile break (e.g., GI spillage).
  • Examples: Penetrating trauma, inflamed appendectomy.
  • SSI Risk: 5-15%.
• Class IV (Dirty/Infected):
  • Existing clinical infection (pus) or perforated viscera.
  • Examples: Abscess I&D, perforated diverticulitis.
  • SSI Risk: >15% (up to 40%).

⭐ This classification is a key predictor of Surgical Site Infection (SSI) risk and directly guides the use of prophylactic antibiotics.

Wound Management - The Clean-Up Job

• Goal: Create a clean, moist, and protected environment for healing.
• Initial Steps: Hemostasis, irrigation (isotonic saline), and assessment.

• Debridement: Removal of necrotic/foreign material.
  • Autolytic: Uses body's own enzymes (e.g., hydrocolloids).
  • Enzymatic: Topical collagenase.
  • Mechanical: Wet-to-dry dressings, irrigation.
  • Surgical: Sharp debridement for extensive necrosis.

⭐ Exam Favorite: Wet-to-dry dressings are a form of mechanical debridement but are non-selective, potentially removing healthy granulation tissue upon removal and causing pain.

Healing Factors & Complications - When Things Go Wrong

• Systemic Factors Impairing Healing:
  • Nutrition: Deficiencies in Protein, Vitamin C, Zinc.
  • Comorbidities: Diabetes (↓ leukocyte function), PVD (ischemia).
  • Lifestyle: Smoking (vasoconstriction, ↓ O₂), chronic alcohol use.
  • Medications: Corticosteroids, chemotherapy, radiation.
• Local Factors:
  • Infection: Most common cause of delayed healing.
  • Poor Perfusion/Hypoxia: Inadequate blood supply.
  • Technique: Excessive suture tension, tissue trauma.

• Specific Complications:
  • Dehiscence: Fascial separation.
  • Evisceration: Organ protrusion (surgical emergency).
  • Hypertrophic Scar: Collagen confined to wound boundaries.
  • Keloid: Collagen extends beyond wound; common in darker skin tones.

⭐ A sudden gush of serosanguinous or "salmon-colored" fluid from an incision 5-8 days post-op is a classic sign of impending fascial dehiscence.

High-Yield Points - ⚡ Biggest Takeaways

• Primary intention sutures clean wounds; secondary intention leaves contaminated wounds open to granulate.
• Wound dehiscence (fascial separation) is a surgical emergency, often preceded by serosanguinous drainage.
• Staph aureus is the most common pathogen in post-op wound infections.
• Keep initial surgical dressings clean and dry for 24-48 hours.
• Healing requires adequate protein, vitamin C, and zinc.
• Evisceration (organ protrusion) requires immediate OR with sterile saline-soaked dressings.