Burns

BURNS MODULE

INTRODUCTION

Burns are a common cause of trauma.  Most burn injuries are a result of flame burns, with scalds also occurring commonly.  Electrical and chemical burns are less common.¹  Concurrent blast injuries can accompany explosions and need to be considered when approaching the patient with major burns.

Burns result in a wide range of morbidity.  In the acute setting, airway burns and inhalational injury can lead to respiratory compromise.  Over a number of hours fluid and electrolyte abnormalities manifest in major burns and can lead to circulatory compromise.

Fires in enclosed spaces pose further danger from the production of toxic gases from the combustion process.  Carbon Monoxide and Cyanide toxicity are potentially lethal complications of smoke inhalation.  Delayed issues with burns include infection, the risk involved with multiple reconstructive surgical procedures and psychosocial issues related to scarring and functional disability.

ASSESSMENT

Comprehensive assessment of the burn is important to identify life and limb threats as well as to determine the depth and estimated surface area of burn, all of which are important prognostically.

In the paediatric population consider non-accidental injury as a mechanism for burn injuries.

Life Threats

Respiratory compromise can manifest quickly in airway and inhalational burns.

The presence of an airway burn necessitates measures to ensure airway protection with early endotracheal intubation.

Consider the possibility of an airway or inhalational burn if there is the presence of:

• Facial or oral burns
• Singed nasal hair
• Carbonaceous sputum
• Tachypnoea
• Stridor
• Hoarseness

Hypovolaemia does not manifest from burns acutely but rather develops over many hours.  The presence of circulatory shock in the early stages of a burn implies an associated injury (eg. blast injury).

Features of Carbon Monoxide and Cyanide toxicity should be sought if the patient was trapped in an enclosed fire with the potential for significant smoke inhalation.

Limb Threats

Limbs with circumferential burns are at risk of vascular compromise. Deep dermal and full thickness burns are inelastic.²  The dry burnt skin is referred to as eschar.  When this is circumferential, it can have a tourniquet effect on the limb which left untreated leads to limb ischaemia.

Depth of Burn^2,3

Accurate burn depth assessment can be difficult, particularly as most burns usually have a mixture of different depths.   Burn depth assessment has implications in guiding treatment as well as predicting recovery.  In general, superficial burns tend to heal spontaneously with little scarring, while deeper burns require surgical intervention.²

Estimation of Surface Area Affected

The total area burnt can be estimated with the Rule of 9s or the more complicated but more accurate Lund Browder Burn Chart.  Do not include skin with just isolated erythema – that is skin with only superficial burns.  The area over the patient’s palm can also be used to approximate 1% body surface area.

Figure 1 Rule of 9s

Figure 2 Lund Browder Burn Chart

MANAGEMENT

The goal of management is to address any life threats whilst expediting definitive therapy – which in major burns is transfer to a dedicated burns facility for operative intervention and rehabilitation.

It is important that associated injuries – particularly traumatic or toxicological – are identified and addressed.

Resuscitation

 Airway & Breathing

• Secure definitive airway early if evidence of significant airway burn or inhalational injury
• Administer high flow oxygen
• Circumferential thoracic burns may mechanically restrict ventilation and requires consideration of an escharotomy

Circulation

• Obtain large bore IV access preferably through unburnt tissue

Other

• Manage associated blast trauma along standard lines.
• Consider Carbon Monoxide or Cyanide toxicity in patients trapped in a fire in an enclosed space.

Specific therapy

• Cool area with running water for 20 minutes

• Dress burns by wrapping affected region with plastic cling wrap after cooling

• Parkland Burns Formula can be used to guide fluid resuscitation, but remember ultimately to use endpoint of urine output >1mL/kg/hrEscharotomy should be performed in instances of circumferential deep dermal or full thickness burns which have resultant circulatory or respiratory compromise.⁴

Figure 3 Escharotomy Guide

Supportive Therapy

• Ensure patient is kept warm, avoid hypothermia
• Ensure adequate analgesia
• Ensure adequate tetanus prophylaxis
• If possible keep burn affected limb/s elevated
• Insert IDC if partial thickness burn > 20% / perineum affected
• Ensure documentation is complete

FURTHER READING

Burns.  Royal Children’s Hospital – Clinical Practice Guideline.  Accessed 6^th December 2010 at http://www.rch.org.au/clinicalguide/cpg.cfm?doc_id=5158

ABC of Burns Introduction. BMJ. 2004; 328: 1366-8.

ABC of Burns I—overview.  BMJ. 2004; 328: 1555-7.

ABC of Burns II—assessment and resuscitation.  BMJ. 2004; 329: 101-3.

REFERENCES

1. Hettiaratchy S, Dziewulski P.  ABC of burns: Introduction. BMJ. 2004; 328: 1366-8.
2. Hettiaratchy S, Papini R.  ABC of burns: Initial management of a major burn: II —assessment and resuscitation.  BMJ. 2004; 329: 101-3. Burns.
3. Royal Children’s Hospital – Clinical Practice Guideline.  Accessed 6^th December 2010 at http://www.rch.org.au/clinicalguide/cpg.cfm?doc_id=5158
4. Indications and Instructions for Escharotomy.  NSW Severe Burn Injury Service.