Burn injuries

Question 1

What are the major mechanisms of burn injury?

Answer 1

Thermal: Scalds, flame, contact with hot objects

Electrical: High-voltage or low-voltage injuries

Chemical: Alkalis, acids, hydrofluoric acid

Radiation: Sunburn, explosion (e.g., gas, propane)

Friction: Abrasion and heat (e.g., road rash)

Light: Intense UV or laser exposure

Question 2

Which mechanism causes the most burns in children and adults?

Answer 2

Children: Scalds (60%)

Adults: Flame burns (50%)

Question 3

What makes hydrofluoric acid burns particularly dangerous?

Answer 3

Causes deep tissue damage via liquefactive necrosis

Penetrates dermis in < 5 mins

Causes severe electrolyte imbalance

Requires calcium gluconate treatment to bind free fluoride ions

Question 4

What tissue is involved in a superficial burn?

Answer 4

Epidermis only

Nerve endings exposed → very painful

Heals in <14 days

Question 5

What are the layers affected in partial thickness burns?

Answer 5

Superficial partial thickness: Top dermis

Deep partial thickness (deep dermal): Deep dermis, possibly hair follicles & sweat glands

Healing time varies: 7–10 days to >21 days

May require grafting if deep

Question 6

What tissues are involved in full thickness burns?

Answer 6

Entire epidermis + dermis + hypodermis

Destroys nerve endings → no pain

Involves blood vessels, may require grafting

Healing by second intention

Question 7

What are the main determinants of burn severity and mortality?

Answer 7

Total Body Surface Area (TBSA) burned

Age of the patient

Depth of the burn

Inhalation injury presence

Co-morbidities

Question 8

What tools are used to assess TBSA?

Answer 8

Wallace’s Rule of Nines (initial assessment)

Lund & Browder Chart (more accurate, used for children/resuscitation)

Question 9

What is Jackson’s Burn Model?

Answer 9

Zone of Coagulation – Irreversible tissue necrosis

Zone of Stasis – Viable but ischemic tissue (can worsen)

Zone of Hyperemia – Viable, will recover

Question 10

How does temperature and exposure time affect burn depth?

Answer 10

70°C – <1 sec → full thickness burn

60°C – 5 sec

50°C – 2–3 mins

45°C – 5 hours

Question 11

What are the priorities in first aid for burns?

Answer 11

Remove cause

Cool burn (30 mins at 15°C water)

Avoid <5°C to prevent deeper injury

Protect airway

Cover with clean dressing (clingfilm, towel)

Prevent hypothermia

Question 12

What is the Parkland formula for fluid resuscitation?

Answer 12

4ml x TBSA (%) x weight (kg)

Give 50% in first 8 hrs, then 50% over next 16 hrs

Use Lactated Ringer’s

Target urine output:

Adults: 0.5–1.0 ml/kg/hr

Children: 1.0–1.5 ml/kg/hr

Question 13

What is the role of escharotomy in burns?

Answer 13

Relieves pressure from rigid, swollen burned tissue

Prevents vascular compromise and nerve damage

Incisions made through eschar, usually without anesthesia

Question 14

What are the systemic effects of major burns?

Answer 14

Hypovolemia, electrolyte loss

Hypermetabolic state (↑ cortisol, catecholamines)

Suppressed immunity → risk of infection

Bone marrow suppression, stress ulcers

Multi-organ dysfunction possible

Question 15

What are the principles of burn wound care?

Answer 15

Blisters: Controversial – tense ones may restrict circulation

Dressings: Absorb exudate, prevent infection, reduce pain

Grafting: If not healed by 3 weeks (2 weeks in kids)

Scar management: Massage, compression, silicone, surgery

Question 16

When is intubation required in inhalation injuries?

Answer 16

Based on clinical signs: shortness of breath, wheezing, stridor, hoarseness, altered consciousness

Inhalation injury causes: hypoxemia, acidosis, systemic toxicity (CO, cyanide)

Contact burn center ASAP