Burns injury

Question 1

Define

Answer 1

• When tissue damage occurs by thermal, electrical or chemical injury

Question 2

How is severity assessed?

Answer 2

• Severity assessed by burn size (% total body surface area) and depth (first to fourth degree).

Question 3

What are the risk factors?

Answer 3

•	Contact with hot objects 
•	Electricity 
•	UV light 
•	Irradiation 
•	Chemicals
•	High Risk Patients
o	Young children
o	Elderly 
o	Male sex

Question 4

What is the pathophyiology?

Answer 4

Local response

Involves the coagulation of injured tissue, and to some degree incites progressive microvascular reactions in the surrounding dermis.

As burns become larger than about 20% of the total body surface area (TBSA), a systemic response ensues, driving fluid loss and release of vasoactive mediators from the injured tissue. Clinically this results in early capillary leak, interstitial oedema, and organ dysfunction. Also, risk of systemic infection.

In well-resuscitated patients, this physiology will self-extinguish and be replaced by a hypermetabolic response, with a near doubling of cardiac output and resting energy expenditure over the next 24 to 48 hours. The magnitude of this response, peaking in those with injuries of 60% or more TBSA, is as high as twice the normal basal metabolic rate.

Question 5

Epidemiology

Answer 5

• UK has > 12,000 admission per year

Question 6

What are the presenting symptoms?

Answer 6

• Note the circumstances of the burn
• Important to find out the time, temperature and length of contact with the agent
• Consider risk of smoke inhalation and carbon monoxide poisoning

Question 7

What are the signs of inhalational injury?

Answer 7

o	Stridor 
o	Dyspnoea
o	Hoarse voice 
o	Soot in nose 
o	Singed nose hairs 
o	Carbonaceous sputum

Question 8

Describe classification of burns according to depth

Answer 8

First-degree burns:
Erythema involving the epidermis only
Usually dry and painful
Typical of severe sunburn.

Second-degree burns:
Superficial partial-thickness burns involving the epidermis and upper dermis
Deep partial-thickness burns involving the epidermis and dermis
Usually wet and painful
Typical of scalding injury.

Third-degree burns:
Full-thickness burns involving the epidermis and dermis and damage to appendages
Usually dry and insensate
Typical of flame or contact injury.

Fourth-degree burns:
Involve underlying subcutaneous tissue, tendon, or bone
Typical of high-voltage electrical injury.

Question 9

What’s the most common wound infection?

Answer 9

cellulitis due to Staph aureus

Question 10

What are the appropriate investigations?

Answer 10

•	Bloods
o	Oxygen saturation, ABG and carboxyhaemoglobin (if inhalational injury)
o	FBC
o	U&Es 
o	Wound biopsy culture and histology
•	Investigations for electrical burns
o	Serum CK 
o	Urine myoglobin (check for muscle damage)
o	ECG