Burns

Assessment

Burn size:

• The rule of nines (arm: 9%; front of trunk 18%; head and neck 9%; leg 18%; back of trunk 18%; perineum 1%).
• Ignore erythema

Burn depth:

• Assessing this can be hard.
• The big distinction is whether the burn is partial thickness (painful, red, and blistered) or full thickness (insensate/ painless; grey-white).
• NB: burns can evolve, particularly over the first 48h.

Resuscitation

1. Resuscitate and arrange transfer to specialist burns unit for all major burns (>25% partial thickness in adults and >20% in children).
2. Assess site, size, and depth of burn, to help calculate fluid requirements
3. Referral is still needed in cases of
   • Full thickness burns >5%
   • Partial thickness burns >10% in adults or >5% in children or the elderly
   • Burns of special sites, chemical and electrical burns, and burns with inhalational injury.
4. Airway
   • Beware of upper airway obstruction developing if hot gases inhaled
   • Consider early intubation
   • Obstruction can develop in the first 24h
5. Breathing
   • Consider escharotomy if chest burns are impairing thorax expansion and normal movement.
   • Give 100% O₂
   • Suspect carbon monoxide poisoning (see acute poisoning article) from history, cherry-red skin, and carboxyhemoglobin level (COHb)
   • Consider hyperbaric O₂ if: pH<7.1; CNS signs; >25% COHb or >20% if pregnant.
   • SpO2 (oximetry) is unreliable in CO poisoning.
6. Circulation
   • Partial thickness burns >10% in a child and >15% in adults require IV fluid resuscitation.
   • Put up 2 large-bore IV lines (14G or 16G)
   • Do not worry if you have to put these through burned skin
   • Intraosseous access is valuable in infants and can be used in adults
   • Secure them well: they are literally lifelines.
   • Fluid Replacement
     • use Parkland formula : 4 * weight (kg) * % of burn = mL Hartmann’s solution in 24h, half given in 1st 8h.
     • Replace fluid from the time of burn, not from the time first seen in hospital
     • Formulae are only guides: adjust IVI according to clinical response and urine output
     • Urine output aim is 0.5mL/kg/h (1mL/kg/h in children), ~50% more in electrical burns and inhalation injury
     • Monitor T° (core and surface);
     • Catheterize the bladder
     • Beware of over-resuscitation which can lead to complications such as abdominal compartment syndrome.

Treatment

1. Cool the burn, warm the patient, Do not apply cold water to extensive burns for long periods: this may intensify shock.
2. Take care with circumferential full thickness burns of the limbs as compartment syndrome may develop rapidly particularly after fluid resuscitation. Decompress (escharotomy and fasciotomy) as needed.
3. If transferring to a burns unit, DO NOT burst blisters or apply any special creams as this can hinder assessment.
4. Simple saline gauze or paraffin gauze is suitable; cling film is useful as a temporary measure and relieves pain.
5. Titrate morphine IV for good analgesia.
6. Ensure tetanus immunity.
7. Antibiotic prophylaxis is not routinely used.

Definitive dressings

• Partial thickness burns, e.g. biological (pigskin, cadaveric skin), synthetic, and silver sulfadiazine cream alone or with cerium nitrate; it forms a leathery eschar which resists infection.
• Major full-thickness burns benefit from early tangential excision and split skin grafts as the burn is a major source of inflammatory cytokines and forms a rich medium for bacterial growth.

Smoke inhalation

1. Consider if:
   • History of exposure to fire and smoke in an enclosed space
   • Hoarseness or change in voice
   • Harsh cough
   • Stridor
   • Burns to face
   • Singed nasal hairs
   • Soot in saliva or sputum
   • Inflamed oropharynx
2. May be accompanied by Free radicals, cyanide compounds (generated, e.g. from burning plastics), and carbon monoxide (CO) (see acute poisoning article, for cyanide and CO poisoning)
3. COHb levels do not correlate well with the severity of poisoning and partly reflect smoking status and urban life. Use nomograms to extrapolate peak levels.
4. 100% O2 is given to elute both cyanide and CO.
5. Involve ICU/anesthetists early if any signs of airway obstruction or respiratory failure: early intubation and ventilation may be useful.
6. Enlist expert help in cyanide poisoning (see acute poisoning article)