Pathology

Extensive burns

• Haemolysis due to damage of erythrocytes by heat and microangiopathy
• Loss of capillary membrane integrity causing plasma leakage into interstitial space
• Extravasation of fluids from the burn site causing hypovolaemic shock (up to 48h after injury)- decreased blood volume and increased haematocrit
• Protein loss
• Secondary infection e.g. Staphylococcus aureus
• ARDS
• Risk of Curlings ulcer (acute peptic stress ulcers)
• Danger of full thickness circumferential burns in an extremity as these may develop compartment syndrome

Healing

• Superficial burns: keratinocytes migrate to form a new layer over the burn site
• Full thickness burns: dermal scarring. Usually need keratinocytes from skin grafts to provide optimal coverage.