What are the main categories of burns?
Which chemicals are worse for burns; acids or alkalis?
Alkalis - penetrate deeper
What are the local effects of burns?
Jackson's burn model
- Zone of Coagulation - irreversible process
- Zone of Stasis - reduced blood flow
- Zone of hyperaemia
What is the systemic pathophysiology seen in burns?
- Fluid loss
- Increased metabolic rate
What layer does a superficial burn affect?
What is the appearence of a superficial burn?
Why do you get fluid loss in burns?
Due to dramatically increased vascular permeability and protein loss
What layers does a partial thickness superficial burn affect?
Epidermis and superficial dermis
What is the appearence of partial thickness superficial burns?
- Blistering - closed blister
How long does it take to heal a superficial burn?
How painful is a superficial burn?
Mild/moderate - due to exposure of sensory nerve endings
Do superficial burns scar?
What layers do partial thickness deep burns affect?
Epidermis down to deep dermis
How long does it take for superficial partial thickness burns to heal?
Up to 3 weeks
How painful is a partial thickness superficial burn?
Which skin layers are involved in full thickness burns?
Into subcutaneous layer
What is the appearence of a full thickness burn?
Dense white, waxy or even charred appearance; note the white leathery appearance of the burnt skin which shines on exposure
Do partial thickness superficial burns scar?
What is the appearence of a partial thickness deep burn?
- Brown blisters
- White tissue
How long does it take for partial thickness deep burns to heal?
How much pain would someone be in with a partial thickness deep burn?
Pain to pressure - The dermal nerve endings are also damaged and hence sensation to pinprick is also lost
Do deep partial thickness burns scar?
Do full thickness burns heal?
Are full thickness burns painful?
No - There is total loss of sensation as all sensory nerve endings within the dermis are destroyed.
How would you calculate surface area for burns?
- Rule of 9's
- Hand surface area is 1%
- Lund and Browder assessment
What are first aid measures for managing burns?
- Run under cold water - 20 minutes
- Remove rings and jewellery
- Anti-inflammatory drugs
- Apply cling film/appropriate dressing
- For chemical burns - irrigate
What problems with breathing can burns cause?
- Inhalation of combustion products/toxic fumes
- CO poisoning
What circulation problems can occur due to burns?
- Fluid loss resulting in shock
- Cardiac arrhythmias
- Decreased urine output
Why can acute kidney injury occur in burns?
In serious burns:
- Vasoconstriction in response to shock
- Red cell haemolysis
- Myoglobin release
Are you more likely to be hypothermic or hyperthermic in severe burns?
What pain medication would you give to someone with severe burns?
10mg morphine and titrate to effect +/- NSAIDs
What vaccination should perople with severe burns recieve?
What is a scald?
Wet heat burns
What happens in the zone of coagulative necrosis?
Inability to conduct heat away from site quick enough -> immediate coagulation of intraceelular proteins which leads to necrosis
What happens in the zone of stasis?
Damage to dermal microcirculation -> tissue ischaemia
This area is DAMAGED but potentially VIABLE
What happens in the zone of hyperaemia?
Reversible increase in blood flow and inflammation - caused by inflammatory mediators released by damaged tissue
What vascular changes occur both locally and systemically in burns victims?
- Increased vascular permeability
- Loss of protein and fluid
- Cell death
Why does the body enter a hypermetabolic state after a burn?
Profound catabolic state
- Release of stress hormones - cortisol, glucagon, various catecholamines
- Suppression/resistance of anabolic hormones - insulin, GH
This state results in muscle protein breakdown, making amino acids available for tissue repair
What immunological effects do burns have?
Immunosuppression - due to the release of cortisol which affects both the humoral and cellular immune mechanisms. Burn wound infection is problematic because it delays healing, encourages scarring and may result in bacteraemia, sepsis or multiple-organ dysfunction. This is why infection is still the leading cause of mortality in burn patients!
What respiratory issue can occur in burns victims?
What are GI effects of burns?
- Stress ulcers
What would you want to elicit from a burns history?
- Time of the injury
- First aid treatment received
Affected area was immersed in water? - how long was it for?
- Any analgesia taken?
- When was the patient last immunised against tetanus?
Does the patient have any relevant PMH? - esp. diabetes
Take relevant drugs? - steroids or warfarin
- Allergic to dressings or antibiotics?
Why is it important to ask about circumstances of a burn that someone has recieved?
Co-existing injuries from:
- Open vs closed space fire
- Jumping/falling whilst trying to escape
- Electrical burns - may have been thrown significant distance
Why is it good practice to run a burn under a cold tap for 20 minutes?
Reduces inflammatory reaction, thus inhibiting progression of zone of necrosis
What must you be careful to avoid when running a burn under a cold tap?
How long should you run a burn on a child under a cold tap?
2 minutes - increased risk of hypothermia
Why would you not want to use ice or iced water?
Causes vasoconstriction which deepens the injury
When getting vascular access in someone with severe burns, what bore size would you use?
2 Large bore cannulas
How would you monitor fluid output in a severely burned individual?
What bloods would you consider taking as part of an ABCDE assesment in a burns victim?
- Group and save/cross-match
What is the most common method used for calculating total body surface area affected by a burn?
Lund Browder Chart
Remember not to include erythema only
What is Wallace's rule of 9's?
This divides the body surface area into areas of nice percent or multiples of nine percent with the only exception being the perineum which accounts for one percent. The rule of nines is relatively accurate for adults but inaccurate in small children
What would you do as part of exposure assessment when performing a primary survey on someone with burns?
- Remove all clothing and jewellery
- Keep the patient warm with blankets or Bair Hugger
- Trim/shave any hair if necessary
- Log-roll the patient to check his back.
What is the Parkland formula for calculating fluid requirements?
4ml X TBSA (%) x Weight (kg) = total mls over 24 hours
Can't use this equation for any TBSA above 50% - if above, just use 50%
Why can individuals who are burnt become hypothermic?
Severely burnt patients, particularly children, are liable to heat loss as blister fluid evaporates and normal capillary control is lost in the damaged skin.
What are important things to consider in terms of management of a burns victim, besides fluid requirements and analgesia?
- Tetanus vaccination
What are the two most important factors determining your management of someone with burns?
- Total body surface area
What is the distinguishing feature of deep partial thickness burns?
Greatly reduced cap refill time - because the burn has destroyed the dermal vascular plexus.
How would you calculate fluid requirements in a child that had >10% burns?
Modified parklands formula = 2 x TBSA (%) x Weight (kg)
Maintenance fluids - 4, 2, 1 rule
How do superficial burns heal?
What is an eschar?
The coagulated dead skin of a full thickness burn
What is the most useful clinical indicator of burn depth?
What is a rough guide to calculating moratlity risk from burns?
TBSA affected + Age = mortality
What is the palm method for calculating burn size?
Use the surface area of the patient's palm, which is equal to 1% of their body surface. This is most appropriate for small burns and in children.
When calculating fluids to give when managing someone with burns, what do you need to take into account first?
- How long it has been since the burn first occured
How much fluid has already been given as resus fluid
- Subtract from overall fluid calculated using parklands
When should resus fluids be considered in an adult with burns?
How would you monitor clinical effectiveness of fluid resuscitation in a burns patient?
- Clinical examination
- Urinary catheter
- Central venous line
When should resus fluids be considered in a child with burns?
What fluid is used in resus of children with burns?
0.9% saline +/- 5% dextrose - modest hepatic glycogen reserves, which can be exhausted quickly, need replacement of glucose
At what TBSA would you consider referring an adult to a burns unit?
At what TBSA would you consider referring a child to a burns unit?
What depth of burns would require referal to a burns unit?
- Full thickness
- >10-15% BSA
- Burns over major joints
What sites would require referral to a burns unit?
What type of fluids are used in adult resuscitation for burns?
What do you need to look for in electrical burns?
Entry and exit point
Why should capillary glucose be monitored during the inital hours of a burn?
Should be routine during the hypermetabolic state as glucose is used, especially for patients with larger burns.
What CVP should you aim for when fluid resuscitating someone with >15% burns?
What would an increased serum lactate in someone with burns indicate?
Reduced tissue perfusion
How much does an inhalation injury increase mortality by?
When would you suspect an inhalation injury?
- Shortness of breath/dyspnoea
- Wheezing and brassy cough
- Hoarse voice
- Closed space injury
- Facial injury
- Singed nasal hair
- Carbonaceous sputum
- Pharyngeal oedema
What are signs of an inhalation injury?
- Soot in respiratory and oral secretions
- Burns around the mouth and face
- Altered consciousness
- Increased respiratory rate and effort of ventilation
What are the different types of inhalation injury?
- Supraglottic (above the larynx)
- Subglottic (below the larynx)
What is the cause of supraglottic inhalation injury?
Primarily a thermal injury to the airways above the larynx and occurs due to the inhalation of hot gases. The damage caused leads to the release of inflammatory mediators which causes oedema of tissues leading to ventilatory obstruction.
What is the cause of subglottic inhalation injury?
Primarily a chemical injury to the alveoli caused by the dissolving of the inhaled products of combustion in the fluid lying over and within the cells lining the respiratory tract
What two chemicals are often implicated in inhalation injuries?
- Carbon monoxide
If you suspected an inhalation injury, what would you do to manage them?
- Give humidified oxygen at 15 litres per minute via a non-re-breathing mask.
- Monitor sats continuously!
- Call for help of your senior and an anaesthetist, as airway oedema may develop rapidly and mechanical ventilatory support may be needed!
What are the 4 major criteria used to determine whether a referral is necessary for a burn?
When would immediate surgery be required to manage a burn?
- Circumferential burns
- A thick, tough, dry eschar around neck
In electrical burns, what is the amount of heat generated proportional to?
- Amount of current
- Tissue resistance
- Duration of contact
Electrical burns - list tissues in terms of their resistance to electrical current; from least to most resistance.
What are the different types of electrical burns?
- Contact: entry and exit
- Flash, arc: exit and re-entry
- Thermal: ignition of clothing and nearby structures.
What extra monitoring do you need to do with electrical burns?
ECG and 24 hours cardiac monitoring
What type of tissue necrosis do acids cause?
Causing a coagulative necrosis (like thermal burns).
What type of tissue necrosis occur in alkali burns?
What are the most commonly implicated acids in chemical burns?
- Sulphuric acid
- Nitric acid
- Hydrochloric acid
- Hydrofluoric acid
What are the most commonly implicated alkali's in chemical burns?
- Sodium and potassium hydroxide
How would you manage chemical burns?
Irrigation, irrigation and irrigation