Burns occur when the skin is damaged by heat sources, electricity, or chemical agents. It only takes 10 seconds of skin exposure to 60°C (140°F) heat for a full-thickness burn to occur.1 Each year around 130,000 people attend hospital for a burn, making it the fourth most common injury in the UK.2,3 These injuries can be life-threatening and require prompt referral and treatment to prevent potential complications and disability. This article will discuss how to assess a patient with burns, estimate the depth and percentage of the total body surface area burnt, as well as the initial management and common complications associated with burns.
Risk factors that increase the likelihood of a person suffering a burn include:4
Patients with burn injuries should undergo a systematic ABCDE assessment. Problems should be addressed as they are identified, and the patient is re-assessed regularly to monitor their response to treatment. Certain areas within this assessment should be focused on in burn patients, and these will be discussed below. Please note that this guide is intended to help students prepare for emergency simulation sessions as part of their training, it is not meant for patient care.
Evaluate the airway and look for signs of an inhalation injury. Inhalation injuries may occur after inhaling hot air, smoke, or toxic fumes and can cause swelling of the airway leading to airway obstruction. There may also be another cause of airway obstruction that is not directly related to the burn (e.g. from facial trauma, a foreign body or vomit in the mouth).3
Factors that may suggest an inhalation injury include:3
If an inhalation injury is recognised or likely given the history, the patient should be sat upright and receive an urgent senior anaesthetic review. Early intubation with an uncut endotracheal tube may be indicated to protect the patient's airway.5
A C-spine injury should also be excluded.
If in doubt, immobilise the cervical spine.
Compromised gas exchange may occur due to carbon monoxide poisoning, inhalation injury to the lower airways, burnt tissue on the chest or neck creating a constrictive eschar, or other traumatic chest injuries such as tension pneumothorax and haemothorax.
Eschar is a collection of tight and leathery dead tissue caused by deep partial or full-thickness burns. When a constrictive eschar forms around the circumference of a limb, it may constrict distal circulation causing limb ischaemia. If eschar forms around the chest, it can prevent adequate chest expansion and cause respiratory distress.
Expose the chest to assess the adequacy of ventilation and look for further injuries. Monitor oxygen saturations with a pulse oximeter and administer 100% high-flow humidified oxygen through a non-rebreather mask as required. Take an arterial blood gas to assess oxygenation and carboxyhaemoglobin levels.
Severe burns may cause circulatory shock due to large fluid losses and systemic inflammatory response. Non-burn injuries may also cause circulatory compromise. Assess blood pressure before inserting two large bore cannulas through unburnt skin and immediately correct any hypotensive shock with warm, intravenous fluids. Take routine blood tests, including FBC, U&Es, LFTs, capillary blood glucose, group and save, a coagulation screen and creatine kinase levels. Insert a urinary catheter for fluid balance monitoring and complete a hydration status assessment.
Evaluate any areas where there are circumferential limb burns:
Regularly check the patient's core temperature and maintain it with active and passive warming as appropriate. Use AVPU or GCS to assess consciousness level.
Expose the patient in sections to minimise cooling, to estimate the percentage of total body surface area (%TBSA) burned, and the depth of the burns. Give a tetanus booster if required.
Once the patient is stable, take a thorough history to assess the following points:
During the ABCDE assessment, estimate the severity of the burns. This involves calculating the percentage of the total body surface area (%TBSA) injured and the depths of each of the burns. Remember to expose in sections to keep the patient as warm as possible.
Accurate estimation of the percentage of the body burnt is important to enable appropriate fluid resuscitation. The morbidity and mortality of the injury are closely related to the surface area injured.
The Wallace Rule of Nines method is commonly used to quickly estimate the percentage of the body burnt in adult patients with medium to large burns. This method divides the body into sections, with each arm and the head each representing 9%, and the chest, back and each full leg representing 18% each. Note that this method is not accurate for children.
The Palmar Surface method is useful to estimate the size of smaller burns or to estimate the size of unburnt surface area in patients with very large burn injuries. The surface area of the patient's entire hand is approximately 0.8% of the total body surface area, and can be used to estimate burns coverage.
Keep in mind that you must use the patient's hand size to estimate the percentage coverage not your own.
The Lund and Browder chart is the most accurate method for assessing burn surface area, as it accounts for different body sizes and shapes, including paediatric patients. The paediatric chart incorporates the effects of growth on the body's relative surface area percentages. This produces a chart where various body parts have different percentages of the total body surface area depending on the patient's age.
Once adequate fluid resuscitation has been administered, the depth of the burns should be examined to guide further treatment. The British Burn Association has created a new classification system that divides burn depth into four categories, taking into account the deepest layer affected, the wound appearance, if it blanches with pressure, how quickly it bleeds after a needle prick, as well as the presence of pain and sensation.
Layers involvedAppearanceBlanchesBleeding on pinprick and CRTSensationPrognosis Superficial
(1st degree)
Only epidermis damaged
Dry & erythematous
Yes
Brisk bleeding and capillary refill
Painful
Heals in 5-10 days without scarring
Superficial Partial
(2nd degree)
Epidermis & upper dermis damaged
Wet, blistered & erythematous
Yes
Brisk bleeding and capillary refill
Painful
Heals in <3 weeks without scarring
Deep Partial
(2nd degree)
Epidermis, upper & lower dermis damaged
Dry, yellow, or white
No
Delayed bleeding, sluggish or absent capillary refill
Decreased sensation
Heals in 3-8 weeks with scarring if >3 weeks to heal
Full Thickness
(3rd degree)
All skin layers to subcutaneous tissues damaged
Dry, leathery or waxy white
No
No bleeding, absent capillary refill
No sensation – painless
Heals in >8 weeks with scarring
This new classification system has replaced the older first, second and third-degree classification system.
Initial wound management includes:
When caring for a burn wound, the first step is to avoid using ice packs or other extremely cold products. To clean the wound, use normal saline and cover the wound loosely with clingfilm. Clingfilm should not be wrapped circumferentially around a limb, as this can create a constrictive eschar and disrupt blood flow.
After a burn, fluids can quickly shift from the intravascular to interstitial fluid compartments, leading to hypovolaemia. A burn percentage of more than 15% of total body surface area in adults or more than 10% in children typically requires formal resuscitation.
Correct any clinical hypovolaemic shock then calculate the patient's additional fluid requirement using the Parkland formula. The initial crystalloid fluid requirement for the first 24 hours is 2-4ml multiplied by the body weight in kilograms multiplied by the total body surface area affected (only include partial or full thickness burns in the calculation). Deficits should be corrected with Hartmann's solution.
The first 50% of the total calculated volume should be given over the first 8 hours since the time of the burn, and the remaining 50% should be given over the subsequent 16 hours. Fluid requirements can be determined by closely monitoring urine output and maintaining it above 0.5ml/kg/hour in adults and 1ml/kg/hr in children to ensure adequate end-organ perfusion.
Burn injuries can be extremely painful, so adequate pain relief should be given early. This can include cooling methods such as running the wound under cold water and covering it with clingfilm, and pharmacological analgesia such as paracetamol, NSAIDs, opioids and ketamine as needed.
Patients should be referred to specialist burn services when any of the following circumstances are present: all burns over 2% total body surface area in children or 3% in adults; all deep partial or full-thickness burns; all circumferential burns; any chemical, electrical or friction burns or cold injuries; any burn not healed in two weeks; any burn with suspicion of non-accidental injury; burns over the perineum, face, hands, feet, genitals or major joints; and pregnant patients or those with serious co-morbidities.
Superficial and superficial partial-thickness burns usually heal naturally within three weeks but deep partial and full-thickness burns often require early excision of the necrotic tissue, followed by a skin graft to aid healing and prevent hypertrophic scar tissue from forming.
Excision of necrotic tissue can be done by either tangential excision (layers of necrotic tissue are gradually removed until the tissue is porcelain white, has small bleeding points and is firm to the touch), fascial excision (in full-thickness burns, all skin and subcutaneous tissue is removed to the level of the fascia) or amputation (in unsalvageable limbs, very deep burns or electrocutions).
After a debrided wound, an autograft (tissue taken from another part of the patient's body) is then placed in theatre. The skin graft, either split thickness (epidermis and upper dermis) or full thickness (all layers of epidermis and dermis), is harvested and surgically joined to the wound edges (with glue, sutures, or staples).
In cases of extremely large burns that cannot be covered with the patient's donor tissue alone, an allograft (from another human donor) or xenograft (from another species, typically a pig) may be used. These grafts act as a temporary measure to cover the wound and prevent infection, wound contractures, and reduce pain.
When formed scars or contractures have matured, further treatment may include scar release, local and regional flaps, skin substitutes, or tissue expansion. Non-surgical treatment can include physiotherapy, corticosteroid injections, cryotherapy, laser treatment, or radiotherapy.
Household chemicals can cause continuous tissue destruction until the pH is neutralised, leading to deep chemical burns. Acidic substances cause damage by coagulative necrosis while alkaline chemicals cause more extensive burns due to liquefactive necrosis. Chemical burns should be immediately irrigated with warm water for at least 30 minutes and all clothing, shoes, and accessories should be removed. Early referral to specialist burn services is essential.
Lightning strikes and contact with power lines can cause large electrical burns with visible entry and exit wounds. This type of burn can cause arrhythmias, myoglobinuria, and rhabdomyolysis from extensive muscle breakdown. Patients should have an ABCDE assessment, ECG, U&Es, urine output monitoring, and Creatine Kinase levels checked. Consider early surgical review in cases of electrical burns to a limb, as it may cause compartment syndrome.
Systemic complications typically manifest in adult patients with burns greater than 25% TBSA, those who are older than 65 or younger than 2, or with simultaneous major trauma or smoke inhalation. Systemic complications may include acute lung injury, rhabdomyolysis, systemic inflammatory response, and multiple organ dysfunction syndrome.
Dehydration and shock can have a variety of effects on the body. Acute kidney injury may result from SIRS, hypovolaemia, and rhabdomyolysis, while electrolyte imbalances may be caused by third space losses and kidney injury. Hypothermia may also be secondary to large volumes of cool fluids being administered, as well as paralytic ileus and Curling's ulcer.
A Curling's ulcer forms when significant hypovolaemia from severe burns causes ischaemia of the gastric mucosa, resulting in a gastric ulcer which may lead to gastrointestinal bleeding or perforation. Starting patients on PPI therapy at admission can reduce the risk of a Curling's ulcer forming.
Local complications may include scarring, contractures, infection, and circumferential eschars. Scarring may be hypertrophic and keloid scars can form in those susceptible, while contractures restrict the range of motion and ability to move joints. Circumferential eschars may reduce chest expansion or distal blood flow, necessitating escharotomy.
An escharotomy requires a scalpel incision down to the level of the subcutaneous fat but not into the muscle or fascia. For circumferential eschars on the limbs, incisions should be made to release both the lateral and medial aspects, while the incision on the torso should release the whole breastplate to allow adequate chest expansion.
The incident and scarring resulting from a burn have the potential for long-term psychosocial impact on the patient, leading to depression, anxiety, PTSD, changes in body image, stigma, and social isolation.
