Surgical Wounds, Traumatic Wounds & Burns
Key Takeaways
- Wound closure occurs via three distinct intentions: Primary (edges approximated with sutures/staples/glue), Secondary (open wound healing by granulation, contraction, and epithelialization), and Tertiary/Delayed Primary (delayed closure after infection resolution or edema reduction).
- Surgical wound dehiscence is driven by systemic (malnutrition, steroids, diabetes) and local (infection, tension) risk factors; emergency evisceration management requires covering exposed viscera with saline-soaked sterile dressings and placing the patient in low-Fowler's position with knees flexed.
- Traumatic wounds are categorized as lacerations, abrasions, puncture wounds, and avulsions, requiring tetanus risk assessment where a booster is mandatory if >5 years have elapsed since the last dose for dirty or contaminated wounds.
- Burn classification ranges from superficial to full-thickness, with adult TBSA estimated using the Rule of Nines and initial fluid resuscitation calculated via the Parkland formula (4 mL × kg × %TBSA over the first 24 hours).
- ABA Burn Center transfer criteria include partial-thickness burns >10% TBSA, full-thickness burns, or critical locations, while atypical wound red flags include Pyoderma Gangrenosum (pathergy contraindicates sharp debridement), Calciphylaxis, and Marjolin's Ulcer.
Surgical Wounds, Traumatic Wounds & Burns
CWCA High-Yield Core Concept: Surgical wound management requires differentiating primary, secondary, and tertiary closure intentions and identifying risk factors for dehiscence and evisceration. Traumatic wounds mandate tetanus risk assessment. Burn care requires accurate depth classification, Total Body Surface Area (TBSA) calculation using the Rule of Nines, Parkland fluid resuscitation, and knowledge of ABA Burn Center referral criteria. Recognizing atypical malignant wounds (Pyoderma Gangrenosum, Calciphylaxis, Marjolin's Ulcer) is vital for proper biopsy and systemic treatment.
Categories of Wound Closure Intentionality
Wounds heal through three recognized modes of surgical closure:
[ Primary Intention ] ──────► Edges Approximated (Sutures/Staples) ──► Rapid Epithelialization
[ Secondary Intention ] ────► Open Wound Base ────────────────────────► Granulation & Contraction
[ Tertiary Intention ] ─────► Delayed Closure (Left open 3-5 days) ──► Secondary Suture Closure
| Closure Intention | Description & Clinical Indications | Healing Characteristics |
|---|---|---|
| Primary Intention | Wound margins are clean and directly approximated using sutures, staples, sterile adhesive strips, or tissue glues (e.g., clean surgical incisions, fresh uncontaminated lacerations). | Minimal tissue loss, rapid epithelialization within 24–48 hours, minimal scar tissue, low infection risk. |
| Secondary Intention | Wound is left open to heal spontaneously from the base upward through granulation tissue formation, myofibroblast-mediated wound contraction, and re-epithelialization (e.g., pressure injuries, VLUs, debrided abscesses). | Significant tissue loss, extended healing timeframe, prominent scarring, high metabolic demand. |
| Tertiary Intention (Delayed Primary) | Wound is deliberately left open for 3 to 5 days to allow edema resolution, drainage of exudate, or treatment of active microvascular infection, followed by primary surgical closure. | Used for heavily contaminated traumatic wounds, compartment syndrome fasciotomies, or ruptured appendicitis surgical sites. |
Surgical Wound Dehiscence and Evisceration
Surgical wound dehiscence is the partial or total separation of previously approximated surgical wound margins prior to complete healing.
[ Surgical Incision ] ──► [ Local/Systemic Risk Factors ] ──► [ Dehiscence ] ──► [ Evisceration (Emergency) ]
Risk Factors for Dehiscence
- Local Factors: Surgical site infection (SSI, primary cause), high wound tension, seroma or hematoma formation, improper suturing technique.
- Systemic Factors: Obesity, uncontrolled diabetes, hypoalbuminemia/malnutrition, chronic systemic corticosteroid use, advanced age, smoking.
- Mechanical Stress: Sudden increases in intra-abdominal pressure (coughing, vomiting, sneezing, straining).
Evisceration Management (Surgical Emergency)
Evisceration is the protrusion of visceral organs (typically loops of small intestine) through a dehisced abdominal surgical incision.
- Immediate Clinical Action: Evisceration is a medical emergency. Cover the exposed viscera immediately with sterile towels or gauze saturated with warm normal saline. Do not attempt to re-insert exposed organs. Place the patient in a low-Fowler's position with knees flexed to reduce abdominal wall tension, maintain NPO status, and notify the surgical team immediately.
Traumatic Wound Etiologies
Traumatic wounds are caused by sudden external physical forces and are classified by mechanism of injury:
- Lacerations: Tearing of skin and underlying soft tissue caused by blunt impact or shear stress over bony structures. Margins may be irregular or devitalized.
- Abrasions: Superficial friction injuries resulting in denudation of the epidermis exposing dermal papillae. Highly painful with weeping serous fluid; requires thorough cleansing to remove foreign debris and prevent traumatic tattooing.
- Puncture Wounds: Deep, narrow wounds caused by pointed objects (nails, glass, animal/human bites). High risk for deep space anaerobic infection (Clostridium tetani, Pseudomonas aeruginosa from puncture through athletic shoe soles). Always evaluate tetanus immunization status (administer booster if $>5$ years since last dose for dirty wounds).
Burn Injury Depth Classification and Resuscitation
Burns are acute thermal, chemical, electrical, or radiation injuries classified by depth of tissue destruction.
+--------------------------------+----------------------------------------+------------------------------------+
| Burn Depth Category | Clinical Presentation & Sensation | Healing & Scar Outcome |
+--------------------------------+----------------------------------------+------------------------------------+
| Superficial (1st Degree) | Erythematous, dry, painful; NO blisters | Heals in 3–7 days; no scarring |
| (Epidermis only) | Intact capillary refill | (e.g., mild sunburn) |
+--------------------------------+----------------------------------------+------------------------------------+
| Superficial Partial-Thickness | Hyperalgesic, wet, weeping blisters; | Heals in 10–21 days; minimal |
| (2nd Degree: Upper Dermis) | Intact rapid capillary refill | scarring |
+--------------------------------+----------------------------------------+------------------------------------+
| Deep Partial-Thickness | Waxy white/pink, dry or diminished | Heals in 21–35 days; high risk |
| (2nd Degree: Reticular Dermis) | sensation; Sluggish or absent refill | of hypertrophic scarring/contracture|
+--------------------------------+----------------------------------------+------------------------------------+
| Full-Thickness (3rd Degree) | Leathery, charred, dry eschar; | Requires surgical excision and |
| (Epidermis, Dermis, Subcut) | PAINLESS (destroyed nerve endings) | skin grafting |
+--------------------------------+----------------------------------------+------------------------------------+
| 4th Degree | Extends into muscle, fascia, or bone | Requires flap reconstruction or |
| | Black, charred appearance | amputation |
+--------------------------------+----------------------------------------+------------------------------------+
Estimating Burn Size: The Rule of Nines
In adult patients, Total Body Surface Area (TBSA) of partial- and full-thickness burns is estimated using the Rule of Nines:
[ Rule of Nines (Adult TBSA) ]
│
┌───────────────────────────┼───────────────────────────┐
▼ ▼ ▼
[ Head & Neck: 9% ] [ Anterior Trunk: 18% ] [ Posterior Trunk: 18% ]
(Chest 9%, Abdomen 9%) (Upper 9%, Lower 9%)
│ │ │
▼ ▼ ▼
[ Each Arm: 9% ] [ Each Leg: 18% ] [ Perineum/Genitalia: 1% ]
(Ant 4.5%, Post 4.5%) (Ant 9%, Post 9%)
Fluid Resuscitation: The Parkland Formula
Patients with $>20%$ TBSA partial- or full-thickness burns require aggressive intravenous fluid resuscitation to prevent burn shock:
- Administration Schedule: Give 50% of the calculated volume over the first 8 hours post-burn injury. Give the remaining 50% over the next 16 hours.
ABA Burn Center Referral Criteria
Transfer to a certified Burn Center is mandated for:
- Partial-thickness burns $> 10%$ TBSA.
- Third-degree (full-thickness) burns in any age group.
- Burns involving sensitive anatomical zones: face, hands, feet, genitalia, perineum, or major joints.
- Electrical burns (including lightning), chemical burns, or inhalation injury.
Atypical and Malignant Wounds Overview
Recognizing non-healing wounds that do not conform to standard etiologies is critical for prompt biopsy and targeted medical therapy.
+---------------------------+--------------------------------------------------+----------------------------------+
| Atypical Pathology | Key Pathophysiological Features | Diagnostic & Therapeutic Strategy|
+---------------------------+--------------------------------------------------+----------------------------------+
| Pyoderma Gangrenosum (PG) | Non-infectious inflammatory neutrophilic | - Diagnosis of exclusion; biopsy |
| | dermatosis linked to Inflammatory Bowel Disease | - **DO NOT DEBRIDE** (Pathergy!) |
| | (IBD) or Rheumatoid Arthritis. Rapidly expanding| - Systemic corticosteroids / |
| | painful ulcer with violaceous undermined borders. | cyclosporine |
+---------------------------+--------------------------------------------------+----------------------------------+
| Calciphylaxis | Calcific uremic arteriolopathy in End-Stage Renal| - Sodium thiosulfate IV |
| (CUAD) | Disease (ESRD). Microvascular calcification causes| - Normalization of calcium/phos |
| | painful purple retiform purpura & black eschar. | - High 1-year mortality rate |
+---------------------------+--------------------------------------------------+----------------------------------+
| Marjolin's Ulcer | Aggressive **Squamous Cell Carcinoma (SCC)** | - Full-thickness edge biopsy |
| | arising within chronic non-healing burn scars, | - Wide surgical excision / |
| | osteomyelitis sinus tracts, or chronic VLUs. | oncological management |
+---------------------------+--------------------------------------------------+----------------------------------+
Critical CWCA Warning: Pathergy in Pyoderma Gangrenosum means that surgical debridement causes rapid wound deterioration and expansion. If PG is suspected, sharp debridement is strictly contraindicated!
What immediate clinical action must be taken if a post-operative abdominal wound suffers evisceration?
An adult patient sustains partial-thickness burns over their entire anterior trunk (18%) and both anterior legs (9% each = 18%), totaling 36% TBSA. Using the Parkland Formula (4 mL x kg x % TBSA), how much Lactated Ringer's fluid should a 70 kg patient receive in the first 8 hours post-burn?
A patient with a history of Ulcerative Colitis presents with a rapidly expanding, extremely painful leg ulcer with violaceous, undermined borders. The clinician suspects Pyoderma Gangrenosum. Why is sharp debridement strictly contraindicated?