12. Burns and Trauma Flashcards
How would you assess a patient
with burns who presents to A&E?
All burns victims are considered ‘trauma patients’ and their assessment
should follow the Advanced Trauma Life Support
(ATLS ) guidelines.
Assessment and resuscitation
must occur simultaneously,
with appropriate
emergency treatment being instigated as injuries are discovered.
History:
> The ATLS ‘AMPLE’ history is a useful mnemonic in emergency situations.
- A – Allergies
- M – Medication
- P – Past illnesses/Pregnancy
- L – Last meal
- E – Events related to the injury
> Establish the mechanism of the burn (e.g. explosion: risk of shrapnel and blast injury; enclosed space: risk of inhalational injury; chemical burn: risk to medical team who should wear protective clothing).
children, be aware of the potential for non-accidental injury.
> Ask specifically about other associated injuries (e.g. patient may have jumped out of a window to escape the fire).
Head injury, fractures or intraabdominal
injury are not uncommon in this cohort.
> Determine the time of injury, as this will guide fluid resuscitation.
Primary survey
> Airway and cervical spine control:
> Airway and cervical spine control:
• Cervical spine fractures must be suspected so immobilise the patient using either manual in-line immobilisation or three-point fixation technique (hard collar, sand bags and tape).
• Look for burns to the face, oedema of the lips and oropharynx, singed eyebrows and nasal hair, carbonaceous sputum and drooling. Listen
for stridor, wheeze, cough or hoarseness. These features suggest inhalational injury and if present, high-flow, humidified O2 via face mask with a reservoir bag should be administered.
• Early endotracheal intubation should be considered as airway oedema can progress rapidly. The endotracheal tube should not be cut shorter
due to the risk of ongoing facial oedema.
• If intubation is needed, call for senior assistance and have the difficult intubation trolley at hand. The patient should remain immobilised during the procedure,
unless a life-threatening
‘can’t intubate, can’t ventilate’ situation arises,
when the airway takes priority over
everything else.
If time permits and the situation is appropriate, consider an awake fibre-optic intubating technique if there is a high clinical suspicion of an unstable cervical spine fracture.
• Suxamethonium is contraindicated from 6 hours to 2 years after a major burn injury because of the risk of severe hyperkalaemia. There is also an increased resistance to non-depolarising neuromuscular
blocking drugs mandating the need for higher doses in these patients.
These effects are thought to be due to changes in the volume of drug distribution, up-regulation of nicotinic ACh receptors, sprouting of extra-junctional ACh receptors and alterations in ACh morphology.
> Breathing:
- Poisoning due to inhalation of carbon monoxide (CO) (generated by fires in enclosed spaces) and cyanide (generated by burning plastic) is a significant risk.
- Oxygen saturations recorded with a pulse oximeter
will be falsely high in the presence of
carboxyhaemoglobin (HbCO)
and therefore a cooximeter,
which can differentiate
HbCO from oxyhaemoglobin,
should be used.
Arterial blood gas samples should be taken.
• Circumferential burns to the chest can restrict ventilation and an escharotomy may be necessary.
These are not usually needed within
the first 6 hours of a burn.
> Circulation and haemorrhage control:
• Burns are associated with large fluid shifts,
as fluid from the intravascular space escapes
into the extracellular tissues,
causing oedema.
Aggressive resuscitation is
required to maintain adequate
cardiac output and minimise
the risk of organ failure.
• Two large-bore 14 G cannula
should be sited; this may be difficult if
the arms and legs are extensively burned.
• Circumferential burns to limbs
can constrict blood supply and may
require escharotomies.
• There are several formulae that can be used to calculate the volume for fluid replacement (e.g. Parkland, Mount Vernon and Brook formulae)
but the ATLS guidelines recommend the use of the Parkland formula:
> Parkland formula = 4 mL/kg crystalloid × % burn
• This is the total volume given
over the first 24 hours:
half of the total volume should
be given over 8 hours,
and the remaining half over 16 hours.
• For the second 24 hours,
administer fluid at a rate of 2 mL/kg
crystalloid × % burn.
• Time is calculated from the time
of the burn and not from the time of
arrival into hospital.
• This formula only provides an estimate of the fluid volume required for resuscitation. In addition to this, the normal daily fluid requirements must be administered.
> Neurological assessment and pain control:
> Neurological assessment and pain control:
• GCS and pupil reactivity must
be assessed as CO poisoning, hypoxia,
hypotension or traumatic head injury
can impair neurological function.
• Burns may be excruciatingly
painful and therefore analgesics,
including opiates,
should be administered promptly.
Wallaces rule of 9s in adults
> Burn assessment and avoidance of hypothermia:
• In an adult, ‘Wallace’s Rule of Nines’ is used to estimate the body surface area (BSA) involved in the burn. The body is divided into anatomical regions that represent 9%, or multiples of 9% of the total body surface; head 9%, arms 9% each, chest and abdomen 18%, back 18% and legs 18% each. The perineum represents 1%.
BSA estimate in kids wallace
• The BSA differs in children,
where the head represents 18% of the
surface area, and the lower limbs
a smaller proportion.
Paediatric burns charts should be
consulted to estimate the extent of the burn.
Depth of burn characteristic and healing duration
• The depth of the burn is important in assessing its severity, in wound management and in determining the ultimate cosmetic and functional results.
Superficial burns (e.g. sunburn) represent damage to the epidermis.
They are erythematous and painful but with no blistering and heal in 2–3 days.
Partial thickness burns represent damage to the
epidermis and dermis.
They are painful, with blisters, and heal in 10
days.
Full-thickness burns represent destruction of the epidermis and dermis down to the subcutaneous fat. Hair follicles and pain receptors are lost and so the burns are white, leathery and painless.
They heal slowly by wound contracture.
Temperature control
• Patients can become hypothermic
rapidly because of impaired homeostasis,
heat loss through burns and the resetting of the
euthermic temperature to approximately 38.5 °C.
This should be minimised by increasing
the ambient temperature, covering exposed
areas and using fluid warmers and heated blankets.
Secondary survey:
Investigations:
Once the patient is stable, a more detailed clinical assessment should be
undertaken.
> Bloods:
• FBC may reveal low Hb from blood loss.
• Electrolytes may show
hyperkalaemia due to rhabdomyolysis.
• Urea and creatinine may be raised in impending or established renal failure.
> C ross-match blood: Patients may need theatre, and blood loss during surgical debridement can be rapid, exceeding 2 mL/kg per 1% of burn treated.
> Blood gas:
• CO poisoning causes hypoxia
with elevated HbCO levels.
• Cyanide poisoning causes hypoxia
with a lactic acidosis and an
increased anion gap.
> ECG: Arrhythmias can occur due to hyperkalaemia, hypoxia, hypoperfusion or acidosis.
> Radiological trauma series: CXR, cervical spine and pelvis.
Which generic management options should be considered in a patient with extensive burns?
Many of these will apply to any sick patient,
and a systems-based approach should be used.
> Analgesia
> Gastrointestinal system: • Patients become hypercatabolic, requiring an increased daily calorie intake and so nasogastric feeding should be started as soon as possible.
• Ulcer prophylaxis should be
given due to the increased
risk of Curling’s ulcers.
> Genito-urinary system:
• A urinary catheter should be
inserted and hourly urine output
monitored (aiming for at least 0.5 mL/kg/h).
• Renal function must be checked daily as there is a high risk of developing rhabdomyolysis and acute renal failure.
> Infection:
• Patients are at increased risk due to loss of the protective skin barrier and generalised immunosuppression.
• Special wound dressings may be used together with topical antimicrobial agents.
Prophylactic antibiotics are not used routinely.
• The patient may require tetanus immunisation.
> Temperature:
Tendency to hypothermia,
which can have widespread effects,
e.g. inhibits clotting,
suppresses the immune system and
impair wound healing.
> Thromboprophylaxis:
Pharmacological (e.g. s/c LMWH) and mechanical thromboprophylaxis if appropriate (e.g. TED stockings +/− pneumatic calf compression).
> Psychological support:
Patients may require counselling and support
to accept both the events causing their injuries
and for the resulting disability or change in appearance.
> Referral to specialist burns centre:
Criteria for transfer include partial or full-thickness burns greater than 10% of BSA in extremes of
ages (less than 10 years or older than 50 years),
partial or full-thickness burns greater
than 20% of BSA in all other age groups,
burns to face,
hands and genitals,
and/or significant chemical burns,
electrical burns or
inhalational injury.
What is the normal range of
carboxyhaemoglobin in the blood?
> Non-smoker 0.3–2%
> Smoker 5–6%.
What are the features of CO
poisoning?
Symptoms of CO poisoning vary
according to the percentage HbCO present,
but no dose–response relationship
has been found. Levels,
therefore, do not predict outcome.
> 0–10% None
10–20% Headache, malaise
30–40% Nausea, vomiting, impaired mental ability
60–70% Cardiovascular collapse and death
What is the half-life of HbCO?
> In air: 4–5 hours
> In 100% oxygen: 1 hour
> In hyperbaric oxygen at 3 atmosphere: 30 min.
