Burns
Key points
Burn Zones
Zone of Coagulation: Maximal damage, non-salvageable tissue
Zone of Stasis: Decreased perfusion, potentially salvageable
Zone of Hyperaemia: Increased blood flow
Inflammatory Mediators
Thromboxane A2, bradykinin, oxidants
Burn Classification
Epidermal: Red, superficial
Superficial Partial Thickness: Blisters, blanching, managed with dressings
Deep Partial Thickness: Delayed blanching, white and mottled, some pain, excision and grafting if not healing within 3 weeks
Full Thickness: Charred, leathery, painless
Estimation of Burn Area
Wallace Rule of 9s: Quick estimation
Lund and Browder Chart: More accurate in children
Palm Method: Patient's palm = 1% TBSA
Do not include superficial (1st-degree) burns
Systemic Effects
Burns >15% TBSA can lead to SIRS
Fluid Resuscitation
Parkland Formula: TBSA x 4ml (3ml in children) x weight = total fluid in first 24 hours
Give half the fluid in the first 8 hours after the burn
Aim for urine output of 0.5-1ml/kg/hr; avoid overhydration
Dressing and Escharotomy
Use Biobrane dressing and antimicrobial agents like silver sulfadiazine
Escharotomy: Incise eschar and skin only, not the fascia
Penile Escharotomy: Done midlaterally to avoid the dorsal vein
Inhalation Injury
Injury: Upper airway damage from direct heat
Toxins: CO displaces Hb curve to the left (headaches, blurred vision, vomiting, collapse); HCN disrupts mitochondrial ATP production (neurological signs, persistent acidosis)
Management: Intubation, nebulisers, inhaled heparin + NAC, pulmonary toilet, 100% O2 (no need for hyperbaric)
Toxic Epidermal Necrolysis (TEN) and Stevens-Johnson Syndrome (SJS)
Causes: Sulfonamides, phenobarbital, lamotrigine, carbamazepine
Pathophysiology: Cytotoxic T lymphocyte release
Management: Supportive care in a burns unit
Chemical Burns
Alkali Burns: Extensive, deep penetration, fat saponification
Hydrofluoric Acid: Fluoride binds calcium, causes hypocalcaemia, prolonged QT
Electrical Burns
Low Voltage: ECG; warn about possible bleeding, scarring if in mouth
High Voltage: Full ATLS, ECG, CK levels
Lightning Strike: Commonly causes side flash injuries
General Management Considerations
Careful history and examination
Involve paediatrics for safeguarding, check for non-accidental injury (NAI)
Antibiotics, assess rabies and tetanus risk
Washout in theatre; primary closure for clean wounds
References
Holcomb and Ashcraft’s Pediatric Surgery, 7th edition, 2020, Chapter 13 Burns
Gourlay, David M, et al. "Burns." Pediatric Surgery NaT, American Pediatric Surgical Association, 2020. Pediatric Surgery Library, www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829114/all/Burns.