Burns in the Emergency Department A High-Yield, Final FRCEM SBA–Focused Guide to Assessment and Management

Why Burns Matter for the Final FRCEM SBA

Burn injuries are high-impact, high-yield topics in the Final FRCEM examination. They test not only factual knowledge but situational judgement, early recognition of deterioration, and prioritisation using an ABCDE framework—all core consultant competencies.

In the UK, approximately 130,000 patients attend Emergency Departments annually with burn injuries, with around 8% requiring admission. Despite representing a minority of trauma presentations, burns carry disproportionate morbidity and mortality, particularly in children, older adults, and vulnerable populations.

For Final SBA candidates, burns questions frequently integrate:

• Airway risk and inhalation injury
• Fluid resuscitation thresholds and formulas
• Recognition of eschar-related compromise
• Referral criteria to specialist burn services
• Safeguarding and non-accidental injury

Definition and Classification of Burns

A burn is a traumatic injury to skin or other organic tissue, caused primarily by thermal or other acute energy exposure.

Types of Burns (Final SBA-Relevant)

🔥 Thermal Burns (Most Common)

• Flame injuries
• Scalds (hot liquids, bath water)
• Contact burns (irons, radiators)

Exam tip:
Scalds dominate paediatric cases, while flame burns are more common in adults.

🧪 Chemical Burns

• Acids → coagulative necrosis
• Alkalis → liquefactive necrosis (deeper penetration)

Key SBA principle:
Alkali burns (e.g. cement) require immediate and prolonged irrigation and often present deceptively mild initially.

⚡ Electrical Burns

• Entry and exit wounds
• Deep tissue and compartment damage may be occult

Always perform an ECG, even in low-voltage domestic injuries, due to arrhythmia risk from alternating current.

❄️ Cold Injury (Frostbite)

• Intra- and extracellular ice crystal formation
• Inflammatory cascade leading to cell death

☢️ Radiation Burns

• Most commonly sunburn
• Also seen in oncology patients receiving radiotherapy

High-Risk Groups in Burn Injuries

👶 Children

• Up to 20% of all burn presentations
• ~70% due to scalds
• ≈20% associated with abuse or neglect

Final SBA red flag:
Always actively exclude non-accidental injury in children and vulnerable adults.

👵 Older Adults (>65 years)

• ~10% of burn patients
• Higher winter incidence
• Mortality ~10%, compared with ~1% overall

Other High-Risk Groups

• Alcohol dependence
• Epilepsy
• Chronic psychiatric illness
• Low socio-economic status

Pathophysiology of Burns

Local Response – Jackson’s Burn Wound Model

1. Zone of Coagulation
   • Irreversible necrosis
   • Maximum thermal damage
2. Zone of Stasis
   • Hypoperfused but viable
   • Potentially salvageable with correct management
3. Zone of Hyperaemia
   • Increased perfusion
   • Fully reversible

Exam insight:
Poor resuscitation converts the zone of stasis into necrosis.

Systemic Response (≥20–30% TBSA)

• Cardiovascular: capillary leak, reduced preload, myocardial depression
• Respiratory: bronchoconstriction, ARDS
• Metabolic: hypermetabolic state (↑ BMR ×3)
• Immunological: global immune suppression

Initial Assessment: ABCDE Approach (Final FRCEM Core)

A – Airway

Mechanisms of compromise

• Generalised oedema
• Direct thermal injury
• Inhalation injury

High-risk features

• Hoarse voice
• Stridor or respiratory distress
• Carbonaceous sputum
• Facial/oropharyngeal burns
• Enclosed-space fire
• Raised CO on blood gas

Management

• Sit upright
• Early senior anaesthetic review
• Early intubation with an uncut tube if risk identified

Common SBA pitfall:
Failure to predict progressive airway compromise.

B – Breathing

Threats

• Inhalation injury
• Carbon monoxide poisoning
• Circumferential chest eschar → restricted ventilation

Key actions

• High-flow oxygen (SpO₂ may be falsely reassuring with CO)
• Early blood gas including COHb
• Consider emergency escharotomy if ventilation compromised

Learning point:
Cyanide poisoning is common in enclosed-space fires—consider early hydroxocobalamin in refractory hypoxia.

C – Circulation

Burns >20% TBSA can cause burn shock, but isolated burns rarely cause immediate hypotension—always search for alternative causes.

Assessment

• TBSA estimation
• CRT, BP, mental state
• Early urinary catheterisation

Investigations

• FBC, U&Es, coagulation, LFTs
• CK (especially electrical burns)
• Group and save if operative risk

Fluid Resuscitation: Parkland Formula (Exam Favourite)

Indications

• Adults: >20% TBSA
• Children: >10% TBSA

Formula
2–4 ml × weight (kg) × %TBSA

• Use 3 ml as standard
• Give 50% in first 8 hours (from time of burn)
• Remaining 50% over next 16 hours
• Use warmed balanced crystalloid (Hartmann’s / Plasma-Lyte)

Urine output targets

• Adults: >0.5 ml/kg/hr
• Children <30 kg: >1 ml/kg/hr
• Double targets if rhabdomyolysis suspected

Disability and Exposure

• Full exposure essential for accurate TBSA and depth assessment
• Actively prevent hypothermia
• Provide early, adequate analgesia (opioids ± ketamine)

Consultant-level tip:
Coordinate exposure, assessment, and photography once, with the whole team present, to reduce heat loss.

Estimating Burn Size and Depth

TBSA Estimation Tools

• Lund & Browder chart (gold standard)
• Rule of 9s
• Patient palm ≈ 1% TBSA
• Mersey Burns App

Exam rule:
Epidermal (erythematous) burns are NOT included in TBSA calculations.

Burn Depth (BBA Classification)

• Epidermal
• Superficial partial thickness
• Deep partial thickness
• Full thickness

For ED decision-making:
Only two distinctions matter:

1. Epidermal vs deeper (for resuscitation decisions)
2. Full thickness vs others (for surgical risk)

Immediate Burn Care: Remove – Cool – Cover

1. Remove
   • Clothing and jewellery
   • Do not remove adherent material
2. Cool
   • Running tap water (~15°C) for 20 minutes
   • Effective up to 3 hours post-burn
   • Never use ice
3. Cover
   • Clean with saline
   • Cling film (not circumferential, not on face)

Electrical Burns: Special Considerations

• Deep tissue damage may exceed skin findings
• High risk of compartment syndrome
• Myoglobinuria → renal failure risk
• ECG mandatory

Asymptomatic patient + normal ECG → no prolonged cardiac monitoring required.

When to Refer to a Specialist Burns Service

British Burn Association Minimum Referral Criteria

• ≥2% TBSA in children
• ≥3% TBSA in adults
• Any full thickness burn
• Circumferential burns
• Burns to face, hands, feet, perineum, genitalia
• Chemical, electrical, friction, or cold burns
• Any suspicion of non-accidental injury

Escharotomy: Life and Limb Saving

Indications

• Ventilatory compromise from chest eschar
• Limb ischaemia from circumferential burns

Principles

• Incise through dermis into fat
• Avoid muscle/fascia
• Release medial and lateral aspects of limbs

Final SBA pearl:
Escharotomy is a time-critical emergency, not a theatre-only procedure.

Key Take-Home Messages for Final FRCEM SBA

• Burns test anticipation, not just reaction
• Early airway decisions save lives
• TBSA and depth guide everything
• Fluid resuscitation is dynamic, not formula-driven alone
• Always consider safeguarding
• Know referral thresholds cold

Trusted References and Backlinks (Exam-Safe)

• RCEMLearning – Major Trauma & Burns
• British Burn Association (BBA)
• London & South East Burns Network (LSEBN)
• NICE & UK national trauma guidance