BURNS Flashcards
Most common type of burn in adults?
Thermal burns - flames
Most common type of burn in children?
Thermal burns - scalds
Types of burns?
Thermal
Chemical
Electrical
Cold exposure
Radiation
Why do chemical burns often cause severe deep dermal burns?
Because the tissue continues to be damaged until the chemical is completely removed
What voltage of electrical burn is usually fatal?
> 70,000 V
What can cause radiation burns?
Sunburn
Radiotherapy
What are considered complex burns?
All chemical and electrical burns
Any thermal burn affecting a critical area (burns to the face, hands, feet, perineum, or genitalia; burns crossing joints; and circumferential burns).
• Any thermal burn covering more than 15% of the TBSA in adults or more than 10% in children (more than 5% in children younger than one year of age).
• Deep partial-thickness burn >1% TBSA
What % of TBSA has to be affected by burns to cause systemic efefcts?
20-30%
What is the model for burns?
Jacksons burn model: three zones of a burn
Zone of coagulation - point of maximum damage so irreversible tissue necrosis here due to coagulation of proteins
Zone of stasis - decreased tissue perfusion and potentially salvageable if burn is managed correctly
Zone of hyperaemia - tissue perfusion increased and is likely reversible
Outline the systemic response to burns?
Release of cytokines and other inflammatory mediators at the site of injury will have a systemic effect once the burn reaches 30% TBSA
• Cardiovascular changes: capillary permeability is increased, peripheral/sphlanchnic vasoconstriction and decreased myocardial contractility = coupled with fluid loss causes systemic hypotension and end-organ hypoperfusion
• Respiratory changes: bronchoconstriction. ARDS in severe burns
• Metabolic changes: basal metabolic rate increases
• Immunological changes: down regulation of immune response
Complications of burns?
Respiratory distress
Poisoning from noxious gases
Hypovolaemic shock from fluid loss
Hypothermia
Wound infections
Sepsis
TSS - mostly in children
Cardiac arrhythmias
Vascular insufficiency, distal ischaemia or compartment syndrome
AKI
Limb loss
Curlings ulcer
Chronic neuropathic pain and itch
Cars and contractures
Psychosocial and sleep disorders
DeathS
What causes TSS secondary to a burn and how does it present?
A burn is colonised by group A strep or staph aureus
Fever, rash, diarrhoea, irritability, poor feeding, tachycardia, tachpnoea 2-4 days post-injury
Which burns are most likely to cause cardiac arrhythmias?
Electrical burns - V fib
Chemical burns - from the electrolyte disturbances
What is a curlings ulcer
When the burn causes ischaemia to the gastric mucosa leading to an ulcer
Prognosis of burns?
Superficial epidermal - heal within 7 days conservatively + no scars
Superficial dermal - 14 days conservative + no scars
Deep dermal - may need surgery + some scars and contractures
Full thickness - needs surgical intervention + significant scars and contractures
3 mechanisms for how burns affect the airway?
Generalised oedema as a systemic response can swell airway and compromise airflow
Localised oedema from direct damage to airway
Inhalation injury
Symptoms that increase suspicion of airway obstruction or inhalation injury after a burn?
• Hoarseness of voice
• Resp distress or stridor -> an indication for immediate intubation!!
• Facial burns
• Singeing of nasal or facial hairs
• Inflamed oropharynx
• Carbon deposits
• Carbonaceous sputum
• Explosion with burns to head or torso
• History or burns in an enclosed space
• Raised CO levels
• Impaired conscious level
How can burns affect breathing/gas exchange?
Gas exchange surfaces and lower airway damage
CO buildup
Eschar - burnt tissue with loss of elasticity around chest reducing expansion
What % TBSA is usually afefcted to cause circulatory shock?
15% in adults
10% in children
What do you worry about with circumferential limb burns?
Compromise blood flow distally and compartment syndrome
How do we calculate fluids after a burn?
Parkland formula
What is the parkland formula?
4mls x %burn x weight (kg) - in 24 hours
Give half in the first 8 hours and the rest in the next 16 hours
What is an escharotomy?
Careful division of burnt tissue to improve ventilation or relieve compartment syndrome
What is an AMPLE history?
The history you take once you have stabilised the pt
Allergies
Meds
PMHx and tetanus status
Last meal
Events - get a better history