Burns

Question 1

What are the types of burns

Answer 1

Thermal
Radiation
Chemical
Electrical
Inhalation

Question 2

Pathophysiology of thermal burns

Answer 2

• Human skin can tolerate temperature of 44 degrees without injury.
• A thermal burn increases the rate at which tissue molecules move and collide with each other. As temperature increases, molecular speed increases, and the cell components begin to break down (especially membranes and proteins) = progressive injury and cell death.

Question 3

Pathophysiology of inhalation injuries

Answer 3

• Terminal bronchioles are the most susceptible as diffusion of gas is rapid and large SA so more gas is absorbed.
• Bronchospasm results from local irritation or vagus-mediated reflex constriction triggered by gas resulting in airway obstruction, hypoxia and atelectasis
• Inactivation of cilia and decreased surfactant production.

Question 4

Superficial burns

Answer 4

• Epidermis only
• Redness, blanching, cap refill presents
• Warm
• Painful

Question 5

Partial thickness burns

Answer 5

• Epidermis plus varying degrees of dermal involvement
• redness, blacnhing, cap refill
• Oedematous skin
• Moist, blisters
• Extreme local pain

Question 6

Full thickness burns

Answer 6

• Epidermis and dermis including basement membrane
• White, pale, leathery appearance
• Dry, sweat glands destroyed
• No capitally refill
• No pain

Question 7

Three phases of burn shock

Answer 7

• Likely to occur in TBSA >15-20% as produces profound pathological effects
  1. Emergent phase: initial reaction to burn including pain and catecholamine release causing vasoconstriction; tachycardia, tachypnoea and HTN.
  2. Fluid shift phase: lasts 18-24 hours - damaged cells release inflammatory mediates, increasing blood flow and capillary permeability = large fluid shift.
  3. Hyper-metabolic phase: days to weeks are body increases metabolic demand to heal.

Question 8

Calculating TBSA for burns in adults

Answer 8

Rule of 9’s:
* head 9%
* Anterior trunk 18%
* Posterior trunk 18%
* each arm: 9%
* Groin 1%
* Each leg: 18%

Question 9

Calculating TBSA for burns in paediatrics

Answer 9

Lund-Browder Chart - refer to chart

Question 10

Systemic responses and burn complications

Answer 10

• hypothermia: tissue destruction impairs body’s ability to retain fluid ad regulate body temperature; evaporation occurs quicker.
• CVS: Increased peripheral vascular resistance and decreased volume = decreased CO; apically permeability;
• Respiratory system: hypoxia
• Infection
• Endocrine demands: increased metabolism due to catecholamine release; water evaporation

Question 11

Management of burns (AT CPG)

Answer 11

1. Assess burn injury: TBSA, burn classification, airway burns.
2. Cool burn for up to 20 mins with running water or using NaCl or wet combine
3. Cover cooled area with cling wrap applied longitudinally to allow for swelling and infection control
4. Airway/breathing: ensure sitting upright and administer 100% O2 if O2 <94% or suspected CO inhalation regardless of SpO2. For unconscious pt: OPA/NPA, suction, ventilate.
5. Assess temperature to avoid hypothermia and shivering - warming techniques..
6. IV fluids for partial or full thickness >10% (adults and pads): 2ml/kg x TBSA over 8 hours
7. Analgesia
8. Salbutamol for wheeze

Question 12

Why is caution taken in airway burns and fluid administration?

Answer 12

Fluid administration for patients with airway burns can lead to extensive systemic oedema and airway compromise