Burns are tissue injuries caused by thermal, chemical, electrical, or radiation exposure. Assessment of burn depth and total body surface area (TBSA) guides fluid resuscitation and specialist referral.
Key Facts
- Rule of Nines for TBSA estimation in adults: Head 9%, each arm 9%, anterior trunk 18%, posterior trunk 18%, each leg 18%, perineum 1%
- Lund and Browder chart: More accurate TBSA assessment; adjusts for age (especially children)
- Parkland formula: Fluid resuscitation - 4mL × body weight (kg) × %TBSA; half in first 8 hours, half in next 16 hours; use Hartmann's solution
- Referral to specialist burns centre (NICE): >10% TBSA (adults), >5% TBSA (children), full-thickness >5%, circumferential, airway/inhalation, chemical, electrical, special areas (face, hands, feet, genitalia, joints)
- Inhalation injury: Suspect if enclosed space fire, singed nasal hairs, carbonaceous sputum, hoarse voice, stridor - EARLY intubation
- Escharotomy: Required for circumferential full-thickness burns causing vascular or respiratory compromise
- Burn depth: Superficial (epidermis only, painful, erythema); partial thickness (dermal, blisters, painful); full thickness (painless, white/charred, no blanching)
- Toxic shock syndrome: Complication of burns (Group A Streptococcus or S. aureus toxin) - fever, rash, hypotension; manage with flucloxacillin + clindamycin
Overview
Key Facts
Burns management requires systematic assessment of depth, area, and associated injuries. Appropriate fluid resuscitation and timely referral to specialist services are critical.
Epidemiology
~175,000 burn injuries/year in UK (most minor). ~13,000 ED attendances for burns. ~4,500 hospital admissions. ~300 deaths annually. Peak populations: Children <5 (scalds) and young adult males (flame burns).
Aetiology
- Thermal: Flame (~35%), scald (~30%), contact (~10%)
- Chemical: Acid, alkali (alkali typically causes deeper injury - liquefactive necrosis)
- Electrical: Low voltage (household), high voltage (>1000V - deep tissue injury, cardiac arrest risk)
- Radiation: Sunburn, industrial
- Non-accidental injury: Consider in children - symmetrical burns, clear demarcation, inconsistent history
Pathophysiology
Jackson's burn model (zones of injury):
- Zone of coagulation: Central; irreversible tissue necrosis
- Zone of stasis: Surrounding; potentially salvageable tissue (at risk of ischaemia in first 48 hours)
- Zone of hyperaemia: Peripheral; will recover
Adequate resuscitation protects the zone of stasis from converting to necrosis.
Clinical Presentation
Burn Depth Assessment
| Depth | Appearance | Sensation | Healing |
|---|---|---|---|
| Superficial (epidermal) | Red, dry, no blisters | Painful | 7-10 days, no scarring |
| Superficial partial | Pink, moist, blisters, blanches | Very painful | 10-14 days, minimal scarring |
| Deep partial | Mottled pink/white, blisters, sluggish blanch | Reduced pain | 3-8 weeks, scarring likely |
| Full thickness | White, waxy, or charred; no blanching | Painless | Does not heal spontaneously - needs grafting |
Red Flags
- Airway: Stridor, hoarseness, carbonaceous sputum, facial burns, singed nasal hairs → EARLY intubation (airway oedema progresses rapidly)
- Circumferential burns: Limb - vascular compromise; chest - respiratory compromise → escharotomy
- Electrical burns: May have minimal skin injury but deep tissue/organ damage; risk of cardiac arrhythmias, compartment syndrome, rhabdomyolysis
- Non-accidental injury: Child with glove/stocking pattern burn, clear tide marks, inconsistent history
Differential Diagnosis
| Burn Type | Key Management Point |
|---|---|
| Thermal | Cool with running water for 20 minutes |
| Chemical (acid) | Copious water irrigation; do NOT neutralise |
| Chemical (alkali) | Copious prolonged irrigation (causes deeper injury than acid) |
| Electrical (low voltage) | ECG monitoring; assess entry/exit wounds |
| Electrical (high voltage) | ICU; ECG, CK, rhabdomyolysis risk; deep tissue injury |
| Radiation | Usually superficial; supportive care |
Diagnosis / Investigation
Bedside
- TBSA assessment: Rule of Nines (adults) or Lund and Browder chart (more accurate, especially children)
- Patient's palm: ~1% TBSA (useful for small or scattered burns)
- Airway assessment: Flexible nasendoscopy if inhalation injury suspected
- ECG: Electrical burns (arrhythmia risk)
Bloods
- FBC, U&Es, LFTs: Baseline
- CK: Rhabdomyolysis (electrical burns, major burns)
- ABG/VBG: CO level (carboxyhaemoglobin) if inhalation injury - co-oximetry
- Lactate: Perfusion marker
- G&S/crossmatch: Major burns
- Clotting: DIC in severe burns
Imaging
- CXR: Inhalation injury, ARDS
- CT: If associated trauma
Management
Immediate (Pre-Hospital and ED)
- Safety: Remove from source of burn; stop the burning process
- Cool: Running tepid water for 20 minutes (effective up to 3 hours post-injury); avoid ice (causes vasoconstriction)
- Cover: Cling film (single layer, loosely) - reduces pain, prevents contamination
- ABCDE: Especially airway - intubate early if inhalation injury suspected
- 100% O₂: If CO poisoning suspected (SpO₂ unreliable - CO gives falsely normal SpO₂)
Fluid Resuscitation (Burns >15% TBSA adults, >10% children)
- Parkland formula: 4mL × weight (kg) × %TBSA burns
- Give 50% in first 8 hours from time of burn (NOT from time of arrival), remaining 50% over next 16 hours
- Use Hartmann's solution (Ringer's lactate)
- Titrate to urine output: Adults 0.5-1 mL/kg/hr; children 1 mL/kg/hr
Wound Management
- Superficial: Simple dressings, analgesia
- Partial thickness: Non-adherent dressings (e.g., Mepitel), silver-based antimicrobials if needed
- Full thickness: Will require surgical debridement and skin grafting
- Escharotomy: Circumferential full-thickness burns causing vascular/respiratory compromise
Referral to Burns Centre
-
10% TBSA (adults), >5% (children), >5% (elderly >60)
- Full-thickness burns >5%
- Circumferential burns
- Face, hands, feet, genitalia, perineum, major joints
- Inhalation injury
- Chemical or electrical burns
- Non-accidental injury
- Pre-existing medical conditions complicating management
Surgical
- Debridement and grafting: Full-thickness and deep partial-thickness burns
- Split-thickness skin graft (SSG): Most common; donor site (thigh) heals spontaneously
- Negative pressure wound therapy: Aids graft take
Prognosis
- Baux score: Mortality estimate = Age + %TBSA (modified Baux adds 17 for inhalation injury)
- Minor burns (<10% TBSA, partial thickness): Excellent prognosis
- Major burns (>40% TBSA): Significant mortality; modern burn centres have improved survival
- Inhalation injury: Doubles mortality for any given TBSA
- Hypertrophic scarring: Common in deep partial and full-thickness burns; managed with pressure garments, silicone, physiotherapy
- Psychological morbidity: PTSD, depression, body image issues - psychological support essential
Other Relevant Information
Rule of Nines (Adults)
| Body Part | % TBSA |
|---|---|
| Head | 9% |
| Each arm | 9% |
| Anterior trunk | 18% |
| Posterior trunk | 18% |
| Each leg | 18% |
| Perineum | 1% |
Parkland Formula
| Parameter | Value |
|---|---|
| Volume | 4mL × weight (kg) × %TBSA |
| First 8 hours | 50% of total |
| Next 16 hours | 50% of total |
| Fluid | Hartmann's solution |
| Target UO | 0.5-1 mL/kg/hr (adult) |