Burns - Assessment and Management

A burn is caused by the coagulative destruction of the skin or mucous membrane. Most burns are minor and can be treated in primary care. Most heal without any problems but complete healing in terms of cosmetic outcome is often dependent on appropriate care, especially within the first few days after the burn. The initial treatment of burns needs to be directed to the following possible injuries:

• Direct thermal injury, producing upper airway oedema and/or obstruction
• Inhalation of products of combustion (carbon particles) and toxic fumes, leading to chemical tracheobronchitis, oedema, and pneumonia
• Carbon monoxide poisoning

• UK admission rate 0.29 per 1,000 with burns or smoke inhalation.
• In the UK it is estimated that about 250,000 people each year present to primary care teams with burn injuries.¹
• Each year over 200 people die as a result of burns and scalds.

Risk factors

• Highest rates were observed in children under the age of 5 and the elderly over the age of 75.²
• About 50% of burns and scalds occur in the kitchen.¹

• Establish the cause: consider non-accidental injury.
• Associated injuries may be sustained while the victim attempts to escape the fire. Explosions may throw the patient some distance and result in internal injures or fractures.
• It is essential that the time of the burn injury is established.
• Burns sustained within an enclosed space suggest possible inhalation injury.
• Pre-existing illnesses, drug therapy, allergies and drug sensitivities are also important.
• Establish patient's tetanus immunisation status.
• Body surface area: Rule of Nines:
  • Adult body is divided into anatomical regions that represent 9%, or multiples of 9%, of the total body surface. Therefore 9% each for the head and each upper limb. 18% each for each lower limb, front of trunk and back of trunk.
  • The palmar surface of the patient's hand, including the fingers, represents approximately 1% of the patient's body surface.
  • Body surface area differs considerably for children - Lund and Browder charts may be used to estimate extent.
  • If not available:
    • For children <1 year: head = 18%, leg = 14%
    • For children >1 year: add 0.5% to leg, subtract 1% from head, for each additional year until adult values attained
• Depth of burn: Previously described as 1st, 2nd, and 3rd degree burns:
  • Superficial partial-thickness - epidermis only: erythema, pain and absence of blisters (e.g. sunburn). Not life-threatening and normally heal within a week without scarring.
  • Superficial partial-thickness - including superficial dermis (papillary layer): often a scald injury, red or mottled appearance with associated swelling and blister formation. The surface may have a weeping, wet appearance and is extremely hypersensitive, even to air current. Heal in 2-3 weeks, minimal scarring, full functional recovery
  • Deep partial-thickness - deep dermis (reticular layer, including superficial parts of hair follicles, sweat, and sebaceous glands). Usually cause hot liquids, steam, flames. Blistering, exposed dermis pale white-yellow, doesn't blanch, no capillary refill, insensate. 3-8 weeks to heal with scarring, may require surgical treatment for best functional recovery.
  • Full-thickness (3rd-degree) - both epidermis and dermis destroyed: causes now include hot oil and contact with hot material. Dark (charred) and leathery. The skin also may appear translucent, mottled, or waxy white (and may be mistaken for unburnt skin). The surface may be red and does not blanch with pressure. The surface is insensate and generally dry. Requires surgical repair and grafting.
  • 4th degree - includes subcutaneous fat, muscle, and perhaps bone: require reconstruction often amputation.
• Cardiac monitoring: dysrhythmias may be the first sign of hypoxia and electrolyte or acid-base abnormalities.
• Circulation: severely burned patients may have accompanying injuries resulting in hypovolaemic shock:
  • Blood pressure may be difficult to obtain and may be unreliable.
  • Monitoring hourly urinary outputs reliably assesses circulating blood volume and so an indwelling urinary catheter should be inserted.

• Initial management for major burns may require resuscitation with attention to airway, breathing, circulation, assessment of conscious level and rapid fluid replacement.^3,4
• Airway:
  • The airway above the glottis is very susceptible to obstruction because of exposure to heat. The clinical presentation of inhalation injury may be subtle and often does not appear in the first 24 hours.
  • Clinical indications of inhalation injury include:
    • Face and/or neck burns.
    • Singeing of the eyebrows and around the nose.
    • Carbon deposits and acute inflammatory changes in the oropharynx.
    • Carbon-particles seen in sputum.
    • Hoarseness.
    • History of impaired awareness, e.g. alcohol or head injury, and/or confinement in a burning environment.
    • Explosion with burns to head and torso.
    • Carboxyhaemoglobin level greater than 10% if patient is involved in a fire.
  • Management of acute inhalation injury:
    • Early management may require endotracheal intubation and mechanical ventilation.
    • Transfer to a burn centre.
    • Stridor is an indication for immediate endotracheal intubation.
    • Circumferential burns of the neck may lead to swelling of the tissues around the airway and so require early intubation.
• Stop the burning process:
  • Remove all clothing - adherent synthetic clothing and tar should be actively cooled with water, and left for formal debridement.
  • Dry chemical powders should be carefully brushed from the wound.
  • Rinse the involved body surface areas with copious amounts of tap water. Cool the burn with tepid water for up to 20 minutes. Great care is required as cooling may cause hypothermia, especially in children,³ and those with extensive burns - may worsen shock.
  • Remove constricting clothing and jewelry before covering the patient with warm, clean and dry linens to prevent hypothermia.
• Breathing:
  • Arterial blood gas determinations should be obtained as a baseline but arterial PO₂ does not reliably predict CO poisoning. Therefore, baseline carboxyhaemoglobin levels should be obtained, and 100% oxygen should be administered.
  • Elevation of the head and chest by 20 to 30 degrees reduces neck and chest wall oedema. If a full-thickness burn of the chest wall leads to severe restriction of the chest wall motion, chest wall escharotomy (burn incised into subcutaneous fat and underlying soft tissue; no anaesthetic is required) may be required.
  • Carbon monoxide (CO) poisoning: has a much greater affinity than oxygen for haemoglobin and so displaces oxygen.
    • Assume carbon monoxide exposure in patients burned in enclosed areas.
    • Diagnosis of CO poisoning is made primarily from a history of exposure.
    • Patients with CO levels of less than 20% usually have no physical symptoms.
    • Higher CO levels may result in headache and nausea, confusion, coma and death.
    • CO dissociates very slowly but this is increased by breathing high-flow oxygen via a non-rebreathing mask.
• Intravenous access:
  • Large-calibre intravenous lines must be established immediately in a peripheral vein.
  • Any patient with burns over more than 20% of the body surface area needs circulatory volume support.
  • Begin infusion with Ringer's lactate solution:
    • The patient requires 2 to 4 mL of Ringer's lactate solution per kilogram body weight per percent second-degree and third-degree body surface burns in the first 24 hours.
    • One-half the total fluid is provided in the first 8 hours after the burn, and the remaining half is administered in the next 16 hours.
    • In children who weigh 30 kg or less, it is necessary to administer maintenance intravenous fluids containing glucose in addition to the burn formula.
    • The Parkland formula may be used: (4ml crystalloid) x (% body surface area burn) x (body weight in kg) = fluid replacement for first 24 hrs, half in first 8 hrs. The Galveston formula may be more accurate in children though more difficult to calculate: 5 litres/m² x % body surface area plus 2 litres/m2/24hr of maintainance.
    • Any resuscitation formula provides only an estimate of fluid need. The amount of fluid given should be adjusted according to the individual patient's response, to maintain a urinary output of 0.5-1ml/kg/hr (adult), or 1-1.5ml/kg/hr (child).
    • Fluid requirement calculations for infusion rates are based on the time from injury, not urinary output from the time fluid resuscitation is initiated.

• Estimate extent and depth of burn.
• Circumferential extremity burns: assess status of distal circulation, checking for cyanosis, impaired capillary refilling or progressive neurological signs. Assessment of peripheral pulses in burn patients is best performed with a Doppler ultrasound.
• Assess for associated injuries
• Weigh the patient
• Flow Sheet: outlining the patient's management; must stay with the patient.
• Baseline determination for the major burn patient:
  • Blood: full blood count, type and cross-match, carboxyhaemoglobin, serum glucose, electrolytes, and pregnancy test in all females of childbearing age. Arterial blood gases.
  • Chest x-ray. Other x-rays may be indicated for associated injuries.

• Circulatory insufficiency caused by a circumferentially burned limb is best relieved by escharotomy. Escharotomies are usually not required within the first 6 hours of burn injury.
• Fasciotomy: seldom required, but may be necessary to restore circulation for patients with associated skeletal trauma, crush injury, high-voltage electrical injury or burns involving tissue beneath the investing fascia.
• Gastric tube insertion: if nausea, vomiting, abdominal distention, or if burns involve more than 20% of the total body surface area.
• Analgesia and sedation:
  • Severely burned patients may be restless and anxious from hypoxaemia or hypovolaemia rather than pain. The patient then responds better to oxygen or increased fluid administration rather than to narcotic analgesics or sedatives that may mask the signs of hypoxaemia or hypovolaemia.
  • Intravenous narcotic analgesics and sedatives may be administered in small, frequent doses.
• Wound care:
  • Partial-thickness (second degree) burns are painful when air currents pass over the burned surface. Gently covering the burn with clean linen relieves the pain and deflects air currents.
  • Do not break blisters or apply an antiseptic agent.
  • Any applied medication must be removed before appropriate antibacterial topical agents can be applied.
  • Application of cold compresses may cause hypothermia. Do not apply cold water to a patient with extensive burns.
• Antibiotics: should be reserved for the treatment of infection.
• Tetanus: determination of immunization status is very important.
• Full thickness burns: require excision and grafting unless are less than 1cm in diameter. Grafting is required within three weeks in order to minimise scarring. Therefore early referral is essential.⁵

• Can result from exposure to acids, alkalies, or petroleum products.
• Alkali burns tend to be deeper and more serious than acid burns.
• Immediately flush away the chemical with large amounts of water for at least 20 to 30 minutes (longer for alkali burns). Alkali burns to the eye require continuous irrigation during the first 8 hours after the burn.
• If dry powder is still present on the skin, brush it away before irrigation with water.

• Are often more serious than they appear on the surface.
• Rhabdomyolysis results in myoglobin release, which can cause acute renal failure. If the urine is dark, start therapy for myoglobinuria immediately.
• Fluid administration should be increased to ensure a urinary output of at least 100 ml/hour in the adult. Mannitol should be given if the pigment does not clear with just increased fluids.
• Metabolic acidosis should be corrected by maintaining adequate perfusion and adding sodium bicarbonate.

• Partial-thickness and thickness burns greater than 10% of the total body surface area in patients less than 10 years or over 50 years of age. Partial-thickness and full-thickness burns greater than 20% total body surface in other age groups.
• Partial-thickness and full-thickness burns involving the face, eyes, ears, hands, feet, genitalia or perineum. Burns involving skin overlying major joints.
• Full-thickness burns greater than 5% body surface area in any age group.
• Significant electrical burns, including lightning injury.
• Significant chemical burns
• Inhalation injury
• Burn injury in patients with preexisting illness, such as diabetes that could complicate management, prolong recovery or affect mortality.
• Children with burn injuries who are seen in hospitals without qualified personnel or equipment to manage their care should be transferred to a burn centre.
• Burn injury in patients who will require special social and emotional support, including cases involving suspected child abuse and neglect.

• Respiratory distress from smoke inhalation or a severe chest burn
• Fluid loss, hypovolaemia and shock
• Infection
• Increased metabolic rate
• Increased plasma viscosity and thrombosis
• Vascular insufficiency and distal ischaemia from a circumferential burn of limb or digit
• Muscle damage from an electrical burn may be severe even with minimal skin injury; rhabdomyolysis may cause renal failure
• Poisoning from inhalation of noxious gases released by burning (e.g. cyanide poisoning due to smouldering plastics)
• Haemoglobinuria and renal damage
• Scarring and possible psychological consequences

• Will depend on depth of burn and body surface area affected.
• Death may result from severe extensive burns or electric shock.