Study sheet: General Surgery Wounds

📋 Course Outline

1. Wound Definitions and Causes
2. Wound Classification
3. Phases of Wound Healing
4. Healing by Intention
5. Factors Affecting Healing
6. Complications of Healing
7. Principles of Wound Management
8. Examination Presentation Plan

📖 1. Wound Definitions and Causes

🔑 Key Concepts & Definitions

• Wound : a break or discontinuity in the skin, mucous membrane, or underlying tissue caused by physical, chemical, or biological injury
• Wound healing : the body’s coordinated process of restoring tissue continuity, structure, and function after injury

📝 Essential Points

• The main causes of wounds are:
  • blunt injury
  • penetrating injury
  • surgical insult
  • burn injury

📖 2. Wound Classification

★ Must-know

📌 Tidy wounds are usually sharp, clean-cut, and single with little or no devitalized tissue, whereas untidy wounds are commonly caused by crushing, tearing, avulsion, vascular injury, or burns and contain irregular or devitalized tissue.

📌 Acute wounds usually heal within the expected time, whereas chronic wounds fail to heal in the expected time and may recur; the slide gives chronic duration as more than 4 weeks to 3 months.

• The four surgical contamination classes are:

  • clean
  • clean-contaminated
  • contaminated
  • dirty or infected

• Superficial wounds involve the epidermis only, partial-thickness wounds involve the epidermis and part of the dermis, and full-thickness wounds involve the entire epidermis and dermis and may extend into fat, muscle, tendon, or bone.

Further detail

📌 Open wounds breach the skin and may expose underlying tissue, whereas closed wounds leave the skin intact despite deeper tissue injury.

💡 Memory Hook

Tidy wounds are clean and sharp, whereas untidy wounds are crushed, torn, or devitalized.

📖 3. Phases of Wound Healing

★ Must-know

• 🔄 Wound healing progresses through:

  1. inflammatory phase
  2. proliferative phase
  3. maturation and remodelling phase

• During the inflammatory phase, hemostasis limits bleeding, neutrophils remove bacteria and debris, and macrophages later become the predominant cells and release cytokines and growth factors.

• The main events of proliferation are:

  • angiogenesis
  • fibroplasia and granulation tissue formation
  • epithelialization
  • wound contraction

• Maturation and remodelling may last a year or longer as collagen is reorganized and the scar gradually gains strength without necessarily regaining the full strength of uninjured tissue.

Further detail

• The inflammatory phase lasts approximately day 0 to day 2–5, and vasoconstriction lasts about 5–10 minutes before vasodilation peaks around 20 minutes.

• Epithelialization usually covers the granulation tissue within 7–10 days, while wound contraction begins at approximately one week and may continue for weeks.

💡 Memory Hook

Inflammation cleans and protects → proliferation fills and covers → maturation strengthens and remodels.

📖 4. Healing by Intention

📝 Essential Points

• Primary intention closes a clean wound with minimal tissue damage by approximating its edges using sutures, staples, or tissue adhesive, producing less tissue loss and a smaller scar.

• Secondary intention leaves a wound open because of infection, extensive trauma, tissue loss, or inability to approximate the edges, and healing occurs through granulation, epithelialization, and contraction.

• Tertiary intention initially leaves a heavily contaminated wound open for cleaning and observation, then closes it later, often after 3–5 days, when bacterial burden has decreased.

💡 Memory Hook

Primary closes the edges, secondary leaves the wound open, and tertiary closes it later.

📖 5. Factors Affecting Healing

📝 Essential Points

• Local factors that impair healing include:

  • infection
  • poor surgical technique
  • movement
  • hematoma
  • tissue ischemia
  • foreign bodies
  • radiation exposure

• Systemic factors that impair wound healing include ageing, inadequate nutrition, uremia, jaundice, diabetes mellitus, malignancy, immunosuppression, smoking, steroids, antineoplastic agents, and NSAIDs.

💡 Memory Hook

Local factors act at the wound, whereas systemic factors arise from the patient.

📖 6. Complications of Healing

🔑 Key Concepts & Definitions

• Dehiscence : separation or breakdown of a previously closed wound
• Evisceration : protrusion of abdominal contents through a disrupted abdominal wound and is an emergency requiring urgent surgical care

★ Must-know

📌 A hypertrophic scar remains within the boundaries of the original wound, whereas a keloid extends beyond the original wound margins.

Further detail

• Other wound-healing complications include:
  • hemorrhage
  • adhesions
  • infection
  • fistula
  • sinus
  • suture complications
  • herniation
  • malignant change

💡 Memory Hook

A hypertrophic scar stays within the wound margins, whereas a keloid extends beyond them.

📖 7. Principles of Wound Management

★ Must-know

• 🔄 Wound management proceeds by:
  1. assessing and stabilizing the patient
  2. examining and documenting the wound
  3. cleaning and irrigating it
  4. debriding when indicated
  5. choosing a closure method
  6. dressing or reconstructing the defect
  7. following up

📌 Management decisions depend on wound type, site, depth, contamination, tissue viability, associated injuries, and the patient’s condition.

Further detail

• Wound assessment includes mechanism, time, site, depth, contamination, tissue loss, foreign bodies, tissue viability, distal circulation, sensation, movement, and associated neurovascular, tendon, or bone injury.

• Reconstruction may require skin grafting or flap coverage when tissue loss is present or important structures are exposed.

💡 Memory Hook

Assess → examine → irrigate → debride → close → dress or reconstruct → follow up.

📖 8. Examination Presentation Plan

★ Must-know

• A 15-mark wound answer should include the definition, causes, classification, phases and types of healing, factors, complications, and management principles.

Further detail

• The recommended diagrams are: a three-phase wound-healing timeline, a comparison of primary versus secondary intention, a wound-management flowchart

📊 Synthesis Tables

Types of Wound Healing

Type	Closure	Main Features
Primary intention	Immediate edge approximation	Less tissue loss and smaller scar
Secondary intention	Wound left open	Granulation, epithelialization, contraction, slower healing, larger scar
Tertiary intention	Delayed closure, often after 3–5 days	Initial cleaning and observation before closure