A Systematic Approach To Burns

What are the unique challenges presented by the burns patient transfer? Here, we will tackle them in a systematic fashion…

Airway

Airway burns can be split into 2 categories – supraglottic vs infraglottic.

Supraglottic Airway Injury

• The majority of injuries are limited to above the glottis as the larynx is highly effective in dissipating heat energy.
• Inspiratory stridor, hoarseness and swollen oropharynx are signs of impending obstruction.

Singed nasal hairs, soot on the face and full thickness burns are strong risk factors for airway compromise.

Infraglottic Airway Injury

• These occur in specific situations (steam inhalation, aspiration of scalding liquid, blast injury, aerosolised chemicals, being trapped in a confined space). Wheezing from bronchospasm, hypersecretion and mucosal ulceration are suggestive of this.
• If concerned with the airway, err on the side of caution prior to transfer as airway oedema worsens with time and fluid resuscitation.
• Large-bore uncut ETTs should be used – these decrease the risk of tube obstruction (from mucus or blood casts) and allows for bronchoscopy & pulmonary lavage.

The tube must be uncut – this is because facial and airway oedema can displace the tube.

• Plan for a difficult airway, and have video laryngoscopes and various tube sizes available.
• Prepare for potential eFONA (emergency Front Of Neck Access i.e. surgical airway). Have a clear plan A, B and C before transferring into the ambulance.
• Don’t forget C-Spine injuries – easy to miss with distracting burns!
• Suxamethonium can be used safely up to 48hours post-injury, after which it may cause a dangerous rise in potassium levels.
• Sit up 30-45° to minimise oedema & deliver standard lung protective ventilation.
• Check the length of tube at the teeth – and monitor regularly throughout the transfer.

Securing the ETT can be tricky depending on the site of the burns…

• Cotton ties – Ensure you have appropriate padding underneath the cotton and check regularly for increasing tension around the tie, which can cause venous congestion.
• Suture – Using a heavy suture, 0 silk, tie a loop around the base of the teeth (upper or lower, not both) with several knots. Create a small knot further from the loop and then secure around the ETT. In an edentulous patient, a small hole can be drilled in the maxillary bone to create the initial knot and then the tube is secured as above.
• Commercial ties are not always present.

Breathing

Lung protective ventilation: Tidal volume 4 – 6ml/kg and ideally target peak pressure <30 cmH20.

• Humidified oxygen therapy for all patients is a standard in burns care, but the following special circumstances should be kept in mind when transferring the burns patient.

Cytotoxic Hypoxia

• CO (Carbon Monoxide) poisoning – clinically can be a spectrum of symptoms ranging from headaches and confusion to coma, arrhythmia and respiratory distress. It can be monitored via a co-oximeter or blood gas results. Neither device will be grossly beneficial whilst on the transfer, so confirm/clarify the diagnosis prior to moving and treat with 100% oxygen until COHb <5%. Hyperbaric oxygen therapy is decided on individual case basis; it is considered if COHb> 25% (20% in pregnant patient) or profound metabolic acidosis with end organ damage or if the patient is unconscious on arrival to the hospital. Hyperbaric oxygen therapy is located in few specific centres, almost always requiring critical care transfer to the centre.
• Cyanide poisoning – be suspicious when treating patients involved in industrial fires with persistent lactic acidosis and cardiovascular instability. Treat with hydroxocobalamin (70mg/kg).

Wear PPE as hydrogen cyanide can be liberated through the patient’s vomitus!

Restrictive Ventilation

• Does the patient require emergency surgery before transfer? Circumferential burns around the chest/torso can limit ventilation. Rarely, it needs to be treated with escharotomies prior to transfer and this must be discussed with the receiving burns unit first.

Blast Lung Injury

• Anatomical and physiological injury following a high-energy explosion, which transmits significant shock waves. Shear waves cause parenchymal tears, supersonic stress waves cause diffuse damage. Rapid compression and expansion of air can cause alveolar rupture.
• This is not easy to diagnose clinically as it presents with a variety of pulmonary contusion, haemorrhage, pneumothoraces, ARDS.
• Vagal reflexes are stimulated and present with characteristic bradycardia, hypotension and apnoeic episodes.
• You must be highly alert and suspicious based on the mechanism of injury. Treat with high flow oxygen, insert chest drains if needed and consider mechanical ventilation.

Circulation

Monitoring the burns patient can be a challenge – use what you can!

• Pulse oximeter can go on the finger, ears, nose, toes….wherever there is a safe target.
• Invasive arterial monitoring is necessary in these critically unwell patients but practically may also be the only option for BP measurement.

Consider inserting a longer arterial line in peripheral zones, as there is risk of line migration due to oedema.

• If ECG dots can’t be used, crocodile clips can be attached to staples or hypodermic needles buried in the skin (in a sterile fashion!)
• Catheterise early for urine output measurement.

Access

• Traditional sites for IV access might be damaged – ideally place through unburned skin, but ensure adequate large-bore cannula and with easy accessibility before transferring out.
• Central lines are often needed for sick and unstable patients, with femoral sites preferred for venous cannulation.
• Ensure that any lines or 3-way-taps are clear of damaged skin, to avoid worsening of the injury.

Treatment

Burn patients suffer from distributive, hypovolaemic and an element of cardiogenic shock. Optimal resuscitation will improve oxygen delivery to the skin.

Fluid Resuscitation

• If: > 20% TBSA (paeds) and > 15% TBSA(adults), use the Parkland Formula to guide fluid management.

Fluid Balance

• Start fluid calculation from time of the injury.
• Use crystalloid of your choice.
• Deduct any fluid (that has already been given) from the total volume.
• You can give further fluid boluses, and potentially 100ml albumin 20%, if no improvement in urine ouput (your end-organ monitoring).
• The risk of fluid overload – potentially peripheral and pulmonary oedema, and abdominal compartment syndrome – is considerable.
• Vasopressor/inotrope use for distributive and cardiogenic shock – particularly if oliguric or anuric and unresponsive to fluid resuscitation.

Be cautious of the hypovolaemic burns patient in the ambulance – they can have a rapid change in haemodynamics and physiology. Refer back to the transfer physiology chapter in Week 2 for more on this.

• Electrolytes – remember the risk of hyperkalaemia (from rhabdomylosis) and other deranged electrolytes from fluid imbalances.

If there is no intact skin to place defibrillation pads in case of a resuscitation, where would you place the electrodes or manage an arrest? Please share your thoughts and experiences in the comment section below – we’d love to canvas your opinion.

Lastly…

D-on’t E-ver F-orget… the further specific management of a burns patient.

References