Overview & Epidemiology

A burn is a type of tissue injury caused by heat, chemicals, electricity, radiation, or friction. Burns remain one of the leading causes of morbidity and mortality worldwide, with an estimated 11 million burn injuries annually requiring medical attention (WHO).

180,000

Annual deaths globally

90%

Occur in LMIC countries

Scalds

Most common in children

Etiology

Thermal

Scalds (hot liquids), flame, contact, flash burns

Chemical

Acids (coagulative), Alkalis (liquefactive – deeper penetration)

Electrical

Low voltage (<1000V), High voltage (>1000V), Lightning

Radiation & Friction

Sunburn, therapeutic radiation, road rash, treadmill burns

Jackson's Burn Wound Model (Three Zones)

Zone of Coagulation (Central): Irreversible tissue necrosis with maximum damage at point of contact.
Zone of Stasis (Intermediate): Decreased perfusion; tissue is potentially salvageable. Adequate resuscitation prevents progression.
Zone of Hyperemia (Peripheral): Increased blood flow with intact tissue that recovers fully within 7 days.

Systemic Response

Burns >20% TBSA trigger a systemic inflammatory response (SIRS) with massive capillary leak, third-spacing of fluids, hypovolemic shock, hypermetabolism (up to 200% of basal metabolic rate), immunosuppression, and catabolism lasting up to 2 years post-injury.

Classification & Depth

Degree Depth Appearance Sensation Healing Example
Superficial
(1st°)		 Epidermis only Erythema, dry, no blisters, blanches with pressure Painful 3–7 days
No scarring		 Sunburn
Superficial Partial
(2nd° superficial)		 Epidermis + papillary dermis Blisters, moist, pink, blanches briskly Very painful (exposed nerve endings) 7–14 days
Minimal scarring		 Hot water scald
Deep Partial
(2nd° deep)		 Epidermis + reticular dermis Pale/mottled, less moist, sluggish capillary refill Pressure sensation only; reduced pin-prick 14–21+ days
Hypertrophic scarring likely		 Oil/grease burn
Full Thickness
(3rd°)		 Entire dermis ± subcutaneous White/waxy/brown/charred, leathery, non-blanching, thrombosed vessels visible Insensate (nerve destruction) Will not heal without surgery
Grafting required		 Flame, prolonged contact
4th Degree Extends to muscle, bone, tendon Charred, exposed deep structures Insensate Amputation may be required High-voltage electrical, prolonged immersion

Clinical Pearl

Burn depth is often underestimated in the first 48–72 hours. Serial reassessment is essential. Laser Doppler Imaging (LDI) at 48h post-burn has >95% accuracy in predicting healing potential.

TBSA Assessment

Total Body Surface Area (TBSA) estimation excludes superficial (first-degree) burns. Only partial and full-thickness burns are counted.

Wallace's Rule of Nines (Adults)

Head & Neck: 9%
Each Upper Limb: 9%
Anterior Trunk: 18%
Posterior Trunk: 18%
Each Lower Limb: 18%
Perineum: 1%

Total = 100%

9% 18% (front) 9% 9% 18% 18% 1%

Lund and Browder Chart

Most accurate method; accounts for age-related body proportion changes. Essential for pediatric burns.

Area 0–1 yr 1–4 yr 5–9 yr 10–14 yr Adult
Head 19% 17% 13% 11% 7%
Each Thigh 5.5% 6.5% 8% 8.5% 9.5%
Each Leg (below knee) 5% 5% 5.5% 6% 7%

Palmar Method

Patient's palm (including fingers) ≈ 1% TBSA. Useful for scattered/irregular burns or very small burns (<15%) and very large burns (>85% — count unburned areas).

Primary Survey (ABCDE)

A – Airway (with C-spine protection)

  • Assess for signs of inhalation injury: singed nasal hairs, facial burns, carbonaceous sputum, hoarseness, stridor
  • Early intubation if ANY concern — airway edema progresses rapidly over 12–24h
  • Use uncut ETT (swelling causes migration); secure with tape, not ties (circumferential ties → ischemia)
  • Consider C-spine immobilization in blast/electrical/fall-related burns

B – Breathing

  • 100% O₂ via non-rebreather mask for all significant burns
  • Assess for circumferential chest burns → restriction → escharotomy
  • CO poisoning: SpO₂ unreliable (reads falsely normal); obtain COHb levels; treat with 100% O₂ (half-life of CO: 4h room air → 40min on 100% O₂)
  • Cyanide poisoning (house fires, burning plastics): Treat with hydroxocobalamin 70mg/kg IV

C – Circulation

  • Two large-bore IV cannulae (through burned skin if necessary)
  • Begin fluid resuscitation if ≥15% TBSA adults, ≥10% children
  • Circumferential limb burns → assess distal pulses hourly → escharotomy if compromised
  • Target MAP >65 mmHg; UOP 0.5–1 mL/kg/hr (adults), 1–2 mL/kg/hr (children)

D – Disability

  • GCS assessment; pupils; blood glucose
  • Altered consciousness: hypoxia, CO/cyanide poisoning, associated head injury, hypovolemia

E – Exposure & Environment

  • Remove all clothing, jewelry, constricting items
  • Cool the burn with running tepid water (15–25°C) for 20 minutes (effective up to 3 hours post-burn)
  • Warm the patient — hypothermia is lethal in burns; maintain core temp >36°C
  • Cover with clean, non-adherent dressing or cling film
  • Log-roll for posterior assessment

Fluid Resuscitation

⚠️ Initiate fluid resuscitation for:

Adults: ≥15% TBSA | Children: ≥10% TBSA | Electrical burns | Inhalation injury

Parkland Formula (Modified Baxter)

4 mL × Body Weight (kg) × %TBSA

First 8 hours

Give 50% of total volume

(from TIME OF BURN, not presentation)

Next 16 hours

Give remaining 50%

Fluid: Ringer's Lactate (Hartmann's solution) — isotonic, contains buffer

Monitoring & Titration

Urine Output Targets

  • Adults: 0.5–1 mL/kg/hr
  • Children: 1–2 mL/kg/hr
  • Electrical burns: 1–1.5 mL/kg/hr (prevent myoglobinuria)

Titration Rules

  • Increase rate by 1/3 if UOP below target
  • Decrease rate by 1/3 if UOP exceeds target
  • Do NOT bolus crystalloid (worsens edema)
  • Consider colloid after 8–12h if volumes exceeding 6mL/kg/%TBSA

Alternative Formulas

Formula Crystalloid Colloid Notes
Parkland 4 mL/kg/%TBSA None in 24h Most widely used
Modified Brooke 2 mL/kg/%TBSA 0.5 mL/kg/%TBSA (day 2) US Military standard
Muir & Barclay — 0.5 mL × kg × %TBSA per period UK; colloid-based; 6 periods

⚡ Fluid Creep Warning

Over-resuscitation causes abdominal compartment syndrome, pulmonary edema, and limb compartment syndrome. The formula is a STARTING POINT only — titrate to endpoints.

Wound Management

Initial Wound Care

  1. Cool with running water (15–25°C) for 20 minutes
  2. Debride loose/devitalized tissue; deroof blisters >2cm (controversial for small intact blisters)
  3. Clean with saline or mild chlorhexidine solution
  4. Apply appropriate topical agent and dressing
  5. Tetanus prophylaxis (TT booster or TIG if unvaccinated)

Topical Agents

Agent Spectrum Advantages Disadvantages
Silver Sulfadiazine 1% (SSD) Broad (Gram+/−, Candida) Painless, easy application Pseudoeschar (mimics infection), neutropenia, delays epithelialization; avoid on face
Mafenide Acetate (Sulfamylon) Excellent Gram−, Pseudomonas, penetrates eschar Eschar penetration; cartilage burns (ears) Painful on application; carbonic anhydrase inhibitor → metabolic acidosis
Nanocrystalline Silver (Acticoat) Broad spectrum Sustained release 3–7 days; less frequent changes Cost; grey discoloration
Bacitracin/Neosporin Gram+ Face & superficial burns; transparent Limited spectrum; contact dermatitis
Honey (medical grade) Broad (osmotic, low pH, H₂O₂) Autolytic debridement; promotes healing; low-resource settings Messy; frequent changes

Dressing Selection by Depth

Superficial / Superficial Partial

  • Non-adherent mesh (Mepitel, Jelonet)
  • Hydrocolloid (DuoDERM)
  • Biosynthetic (Biobrane) for pediatric scalds

Deep Partial / Full Thickness

  • Silver-based antimicrobial dressings
  • Negative-pressure wound therapy (NPWT)
  • Temporary skin substitutes pending grafting

Inhalation Injury

Present in 10–20% of burn admissions; increases mortality by 20% at any given TBSA. Increases fluid requirements by 40–50%.

Three Components

1. Thermal Injury (Supraglottic)

Heat dissipates above vocal cords. Causes massive supraglottic edema. Peaks 12–36h. Requires early intubation.

2. Chemical/Smoke Injury (Tracheobronchial)

Particulate matter and toxic gases damage bronchial epithelium → bronchospasm, mucosal sloughing, cast formation, ARDS. Diagnosed by bronchoscopy (gold standard).

3. Systemic Toxicity

CO poisoning: Cherry-red skin (unreliable); headache, confusion, coma. COHb >10% significant, >60% fatal. Treat: 100% O₂; hyperbaric if COHb >25%, pregnant, neurological symptoms.

Cyanide: Altered consciousness, lactic acidosis (lactate >10 mmol/L), cardiovascular collapse. Treat: hydroxocobalamin 5g IV (adults).

Management

  • Early intubation (large ETT ≥7.5mm for toilet bronchoscopy)
  • Lung-protective ventilation (6 mL/kg IBW, PEEP, permissive hypercapnia)
  • Nebulized heparin (5000 IU) + N-acetylcysteine alternating q2h for 7 days
  • Aggressive pulmonary toilet; chest physiotherapy
  • Prophylactic antibiotics NOT recommended

Electrical & Chemical Burns

Electrical Burns

Surface burns underestimate damage — "iceberg injury". Deep tissue destruction follows the path of least resistance.

  • Entry/Exit wounds: Identify and document
  • Cardiac: ECG mandatory; arrhythmias (VF, asystole). Monitor 24h if abnormal ECG, LOC, or high voltage
  • Rhabdomyolysis: CK, myoglobinuria → aggressive hydration (UOP 1–1.5 mL/kg/hr), mannitol, bicarbonate to alkalinize urine (pH >6.5)
  • Compartment syndrome: Fasciotomy > escharotomy
  • Spine fractures: Tetanic contractions can cause vertebral compression fractures
  • Cataracts: Delayed (months–years); ophthalmology follow-up
  • Oral commissure burns (children): Labial artery hemorrhage risk at 7–21 days when eschar separates

Chemical Burns

Severity depends on: agent, concentration, duration of contact, mechanism of action, volume.

  • Immediate copious irrigation with water for minimum 30–60 minutes
  • Remove all contaminated clothing
  • Do NOT attempt neutralization (exothermic reaction)
  • Alkalis worse than acids: Liquefactive necrosis allows deeper penetration; require longer irrigation
  • Hydrofluoric acid (HF): Life-threatening hypocalcemia, hypomagnesemia. Treat with topical calcium gluconate gel 2.5%; subdermal/intra-arterial calcium for digits; cardiac monitoring
  • Phosphorus burns: Keep moist; debride visible particles under UV (luminescent); copper sulfate 1% identifies particles (turns black)
  • Cement burns: Alkaline (pH 12–13); often present late; prolonged irrigation essential

Pain & Analgesia

Burns are among the most painful injuries. Multimodal analgesia is essential. Pain types: background pain (constant), procedural pain (dressings), breakthrough pain.

Level Agent Notes
Mild Paracetamol + NSAIDs Base for all regimens; regular dosing
Moderate Tramadol, Codeine Transition agents
Severe/Procedural IV Morphine, Fentanyl PCA pump; titrate to effect; beware respiratory depression
Procedural Ketamine (0.5–1 mg/kg IV) Dissociative analgesia; maintains airway reflexes; ideal for dressing changes
Neuropathic Gabapentin, Pregabalin Start early; escalating itch/dysesthesia
Anxiolysis Midazolam, Lorazepam For anticipatory anxiety; complement not substitute

Non-pharmacological: Distraction (VR gaming shows 35–50% pain reduction), music therapy, cognitive behavioral therapy, splinting, elevation.

Nutrition & Metabolism

Major burns cause hypermetabolism lasting up to 2 years. Metabolic rate increases 40–100% above baseline. Muscle catabolism, insulin resistance, and immune dysfunction result.

Caloric Requirements

Curreri Formula (Adults)

25 kcal/kg/day + 40 kcal × %TBSA

Toronto Formula

More accurate; accounts for fever, days post-burn. Indirect calorimetry is gold standard.

Macronutrient Goals

  • Protein: 1.5–2 g/kg/day (up to 25% of calories); glutamine supplementation 0.5 g/kg/day
  • Carbohydrates: 55–60% of calories; maximum glucose oxidation 5 mg/kg/min
  • Fat: <20–25% of calories (excess impairs immunity)

Key Interventions

  • Begin enteral nutrition within 6–12 hours (reduces bacterial translocation, ileus, mortality)
  • Maintain ambient temperature 28–33°C (thermoneutral range) to reduce metabolic demand
  • Oxandrolone 0.1 mg/kg BID (anabolic steroid; improves lean body mass, wound healing)
  • Propranolol (reduce heart rate by 15–20%): Attenuates hypermetabolism, prevents muscle wasting
  • Insulin infusion to maintain glucose 110–140 mg/dL (reduces infections, improves donor site healing)
  • Micronutrients: Vitamin C (1g BID), Zinc (220mg daily), Vitamin D, Selenium, Copper

Surgical Management

Escharotomy

Indication: Circumferential full-thickness burns with vascular compromise (limbs) or respiratory compromise (chest).

Technique: Full-thickness incision through eschar to subcutaneous fat; mid-axial lines on limbs; anterior axillary lines on chest extending to form "H" pattern.

Timing: Emergency bedside procedure; no anesthesia needed (insensate eschar).

Early Excision & Grafting

Current standard of care. Performed within 24–72 hours for deep partial/full-thickness burns. Reduces sepsis, shortens hospital stay, improves survival.

Excision Types

Tangential Excision (Janzekovic)

Sequential shaving of thin layers until viable tissue (punctate bleeding). Preferred for partial-thickness. Blood loss: significant.

Fascial Excision

Excision down to fascia. For massive full-thickness. Less blood loss, reliable graft bed, but poor cosmesis and lymphedema.

Skin Grafting

Type Description Indication
Split-thickness (STSG) Epidermis + partial dermis (0.008–0.012 inch) Workhorse; can be meshed 1:1.5 to 1:6 for coverage
Full-thickness (FTSG) Epidermis + full dermis Face, hands, joints (less contracture)
Cultured Epithelial Autograft (CEA) Keratinocytes grown in lab (3 weeks) Massive burns with limited donor sites
Dermal Substitutes Integra, MatriDerm, AlloDerm Provides dermal scaffold; two-stage procedure with Integra

Temporary Coverage Options

  • Allograft (cadaveric skin): Gold standard temporary coverage; vascularizes then rejects (10–14 days)
  • Xenograft (porcine): Temporary adherent dressing
  • Biobrane: Biosynthetic; excellent for superficial partial-thickness pediatric scalds
  • Amnion: Low cost, available in LMIC; anti-inflammatory properties

Complications

Early (0–72 hours)

  • Hypovolemic shock
  • Airway compromise
  • Compartment syndrome
  • Abdominal compartment syndrome (fluid creep)
  • Hypothermia
  • Electrolyte derangements (hyperkalemia in electrical)

Intermediate (3–14 days)

  • Burn wound sepsis (most common cause of death after 72h)
  • Pneumonia / VAP
  • UTI (catheter-associated)
  • Line sepsis
  • Curling's ulcer (stress gastric ulcer) — prevented by early enteral feeding, PPI/H2 blockers
  • DVT/PE
  • ARDS

Late (>14 days)

  • Hypertrophic scarring (most common long-term complication)
  • Contractures (especially flexor surfaces, neck, axilla)
  • Marjolin's ulcer (SCC in chronic burn scars; latency 20–30 years)
  • Heterotopic ossification (periarticular)
  • Neuropathy

Systemic

  • PTSD, depression, anxiety (30–45% of survivors)
  • Body image disturbance
  • Growth retardation (pediatric)
  • Chronic pain syndromes
  • Insulin resistance; metabolic syndrome

Burn Wound Infection Diagnosis

Clinical signs: increased pain, erythema/warmth at margins, purulent discharge, graft loss, change in wound color/odor. Quantitative wound biopsy >10⁵ organisms/g tissue = wound infection (gold standard). Surface swabs are unreliable.

Burn Center Referral Criteria

American Burn Association (ABA) Criteria for Burn Center Referral:

  1. Partial-thickness burns >10% TBSA
  2. Burns involving face, hands, feet, genitalia, perineum, or major joints
  3. Full-thickness (3rd degree) burns of any size
  4. Electrical burns (including lightning)
  5. Chemical burns
  6. Inhalation injury
  7. Burns in patients with significant comorbidities
  8. Burns with concomitant trauma (if burn is greatest risk)
  9. Burns in children (facilities without pediatric expertise)
  10. Burns requiring special social, emotional, or rehabilitative intervention (suspected abuse)

Pediatric Burns

⚠️ Non-Accidental Injury (NAI) Red Flags

  • Delayed presentation
  • Inconsistent history with injury pattern
  • Symmetrical or "stocking/glove" pattern (forced immersion)
  • Clear tide-mark with no splash marks
  • Cigarette burns (circular, uniform depth)
  • Multiple burns at different stages of healing
  • Injuries to buttocks/perineum in toilet-training age

Key Differences in Pediatric Burns

  • TBSA: Use Lund & Browder chart (larger head, smaller limbs proportionally)
  • Fluid: Parkland formula PLUS maintenance fluids (4-2-1 rule) with dextrose-containing (hypoglycemia risk)
  • Resuscitation threshold: ≥10% TBSA (vs 15% adults)
  • UOP target: 1–2 mL/kg/hr (infants); 1 mL/kg/hr (older children)
  • Hypothermia: Greater surface area:volume ratio → rapid heat loss
  • Scalds: Most common mechanism; thinner skin = deeper burn at same temperature
  • Biobrane/Suprathel: Excellent for pediatric superficial partial-thickness (avoids painful dressing changes)

Rehabilitation

Begins on Day 1 of admission. Burns rehabilitation is lifelong for major burns.

Scar Management

  • Pressure garments: 15–25 mmHg, 23 hours/day for 12–18 months; start when wounds closed
  • Silicone sheets/gels: Hydration and occlusion; reduce hypertrophic scarring
  • Massage: Deep friction massage once wounds closed; improves pliability
  • Intralesional steroids: Triamcinolone 10–40 mg/mL for established hypertrophic scars/keloids
  • Laser therapy: PDL (vascular), fractional CO₂ (remodeling), IPL

Positioning & Splinting (Anti-Contracture)

Joint Position of Comfort (Contracture) Anti-Contracture Position
Neck Flexion Extension (no pillow)
Shoulder Adduction Abduction 90°, slight forward flexion
Elbow Flexion Extension
Wrist Flexion 20–30° extension
Hand (MCP) Extension/hyperextension 70–90° flexion (intrinsic plus)
IP joints Flexion Full extension
Hip Flexion Extension, neutral rotation
Knee Flexion Extension
Ankle Plantarflexion Dorsiflexion (neutral 90°)

Multidisciplinary Team

Burns Surgeon Intensivist Physiotherapist Occupational Therapist Dietitian Psychologist Social Worker Pain Specialist Wound Care Nurse Plastic Surgeon

Psychological Support

  • Screen for PTSD, depression, anxiety at discharge and follow-up
  • Cognitive behavioral therapy (CBT) — strongest evidence
  • Peer support programs and burn survivor camps (especially pediatric)
  • Body image counseling; social reintegration programs

Prognostic Scores

Baux Score

Mortality ≈ Age + %TBSA

Revised Baux: Age + %TBSA + 17(if inhalation injury)

ABSI Score

Abbreviated Burn Severity Index: Sex, age, TBSA, inhalation, full-thickness → probability of survival

Modern Outcomes

With advances in resuscitation, early excision, critical care, and nutrition, LD50 (lethal dose for 50% mortality) has improved from ~30% TBSA in the 1950s to approximately 70–80% TBSA in young adults at specialized centers today.