Burns are injuries to tissue caused by heat, chemicals, and/or radiation. The two factors that influence the severity of a burn are its depth and the surface area involved. Accordingly, burns are classified into four grades based on the depth of tissue involvement. Lund-Browder charts are used to calculate the surface area involved. Massive tissue necrosis, which occurs with severe burns, results in sepsis, shock, and sequential organ failure (see for details). In the case of severe burns, patients should be intubated, given supplemental oxygen, and resuscitated with IV fluids. Different formulas exist to calculate initial fluid requirement, but fluids should be adjusted to maintain clinical stability and appropriate urine output. Pulse oximetry, blood gas analysis, and measurement of electrolyte and creatinine levels are important diagnostic procedures for patients with severe burns. In the case of circumferential burns around limbs, peripheral pulses and capillary refill can be used to detect perfusion. Escharotomy should be performed in order to treat compartment syndrome and prevent acute limb ischemia. First and second-degree burns can be treated with antiseptic ointment and dressings. Treatment of third and fourth-degree burns involves debridement of necrotic tissue followed by skin graft or a tissue transfer via flap. Burn wounds tend to become infected and large, severe burns tend to be fatal injuries. The most common causes of death following burns are shock, sepsis, and respiratory failure.
- Local changes at the burn site (Jackson model of the burn wound) 
- Zone of coagulation: a central zone of irreversible, coagulative necrosis
- Zone of stasis: surrounds the central zone of coagulation and is comprised of damaged but viable tissue with decreased perfusion
- Zone of hyperemia: surrounds the zone of stasis and is characterized by inflammation and increased blood flow
- Almost all burns are colonized by bacteria; common pathogens that infect burn wounds include MRSA, Pseudomonas, Klebsiella, Acinetobacter, and Candida
- Eschars can cause constrictive effects.
A burn wound is a dynamic wound. If resuscitation and/or wound care are not adequate, the zone of stasis becomes irreversibly damaged and the depth of the burn increases.
Systemic effects 
- Release of cytokines and other inflammatory mediators → systemic inflammatory response syndrome
- Evaporative fluid loss → hypothermia, dehydration
- Hemolysis, muscle damage → hemoglobinuria and/or myoglobinuria →
|Classification of burns|
Degree of burns
|Affected tissue layers|| |
Clinical features 
|Pain||Wound blanching on pressure||Appearance|
1st-degree burn (superficial burn)
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|2a (superficial partial-thickness burn)|| || |
|2b (deep partial-thickness burn)|| || || |
3rd-degree burn (full thickness burn)
| || || |
4th-degree burn (deeper injury burn)
| || |
In cases of severe, deep burns, pain may be absent as a result of damage to sensory nerve endings.
Extent of burns (surface area involved) 
- Age-specific charts are used to calculate the surface area covered by a burn.
- Most accurate method for both adults and children
- The palm accounts for 1% of the total body area.
- It is the least reliable method.
Wallace's rule of nines
- A quick but reliable method for estimating the surface area covered by burns in the case of adults.
- The rule of nines is unreliable among children.
|Body surface area estimation|
|Trunk||36% (4 x 9%)|
|Arms||18% (2 x 9%)|
|Thighs||18% (2 x 9%)||14.5%||13.5%|
|Lower legs and feet||18% (2 x 9%)||14.5%||13.5%|
- Clinical features of ; (e.g., hypotension, poor urine output) and/or (e.g., dyspnea)
- In case of circumferential burns around limbs:
- In case of circumferential burns around abdomen:
In adults, shock sets in if burns involve > 15% of the body surface. Burns that involve 50–70% of the body surface are usually lethal.
In children, signs of shock appear if > 10% of the body surface is involved. Burns that involve 60–80% of the body surface are usually lethal.
- Pulse oximetry
- Blood tests
- Wound swab and blood cultures: if wound infection or sepsis is suspected
Immediate measures in case of severe burns
- Airway management: intubation and high flow oxygen therapy is indicated if an inhalation injury is suspected or if burns involve more than 30–40% of the body surface. Do not delay intubation if needed, as fluid resuscitation can increase laryngeal swelling, which will complicate intubation
Begin initial with crystalloids, usually lactated Ringer's solution (RL)
In adults and children ≥ age 14
- Parkland formula was traditionally used to guide initial fluid therapy: the volume of lactated Ringer's solution to be administered within a period of 24 h = 4 mL x % of total body surface involved in 2nd and 3rd-degree burns x body weight (in kg)
- Current recommendations by the ATLS and the American Burn Association: volume of lactated Ringer's solution to be administered within a period of 24 h = 2 mL x % of body surface involved in 2nd and 3rd-degree burns x body weight (in kg)
- Half of this volume should be administered within the first 8 hours and the remaining half within the next 16 hours
- In children < age 14
- Volume of lactated Ringer's solution to be administered within a period of 24 h = 3 mL x % of body surface involved in 2nd and 3rd-degree burns x body weight (in kg)
- Infants and small children ≤ 30 kg: initial fluid therapy for a 24 hour period as above + 24 h maintenance fluid requirement of a glucose-containing solution 
- Note that this is an INITIAL estimate for fluid requirements: fluid therapy should be modified to achieve a urine output of 0.5 mL/kg/h in adults and 1 mL/kg/h in children (< 30 kg).
- In adults and children ≥ age 14
Manage the burn area
- Remove any burnt clothing
- Cool the burnt area with cool running water or saline-soaked gauzes. Cover the wound with a sterile dressing.
Because of studies demonstrating serious complications from over-resuscitation (e.g., pleural effusions and compartment syndrome), the ATLS and American Burn Association now recommend only giving half of the fluid resuscitation volume that is calculated by the Parkland formula in adults; i.e., 2 mL x %TBSA x weight (kg) instead of 4 mL). The volume is still given over 24 hours, with one half given in the first 8 hours and the remaining half over the next 16 hours.
Do not use ice or ice water.
- Tetanus prophylaxis
- Analgesia (opiates often necessary)
- Proton pump inhibitors or H2 antagonists: prophylaxis against Curling's ulcers (see and )
- Following resuscitation, the patient should be transported to a special burn unit in the following situations:
- Prophylactic systemic antibiotic therapy is not routinely recommended.
Management based on degree
1st and 2nd-degree burns
- Topical moisturizers (e.g., calamine lotion) or aloe vera-based gels: relieve symptoms of 1st-degree burns
- Consider antiseptic ointments (e.g., silver sulfadiazine, mafenide) or topical antibiotics (bacitracin; triple antibiotic ointments are a combination of bacitracin neomycin, polymyxin B)
- Deroofing bullae/vesicles
- Dressing is indicated in partial thickness (2nd-degree) burns.
3rd and 4th-degree burns
- Early debridement of burnt, necrotic tissue
- Method of tissue coverage varies depending on the specific burn characteristics. Options include:
- Topical antibiotics (e.g., silver sulfadiazine, bacitracin, neomycin)
Burn eschars: specific measures
- For circumferential burn
- Perform a doppler test, as well as check the capillary refill time, peripheral pulses, sensations, and pulse oximetry in the limb hourly for 24–48 hours
- If NO impending vascular/respiratory compromise or compartment syndrome:
- Elevate the lower limb or torso
- Perform a range of motion exercises as tolerated
If vascular/respiratory compromise or compartment syndrome is impending or has occurred :
- If develops: fasciotomy
- For chest/neck eschars:
- If respiratory compromise impending or has occurred → escharotomy
Chemical burns: specific measures
- Immediate, copious irrigation of all areas of exposure with water, prior to or on the way to the hospital.
- ↑ Shock, sepsis, and respiratory failure are the most common causes of death following burns (see “Pathophysiology” above).
- Curling ulcers (see )
- Keloid formation, contractures
- Complications of chemical burns
- Complications of electrical burns: arrhythmias, trauma
We list the most important complications. The selection is not exhaustive.
- Definition: damage to the respiratory tract that occurs due to the inhalation of hot smoke and/or noxious gases
- Etiology: inhalation of hot smoke, particles (< 1 μm diameter in size), and/or irritant/noxious gases (e.g., ammonia, chlorine)
- Clinical features
- Inhalation injury should be suspected when any of the following are present:
- In case of suspected inhalation injury, the following additional tests should be performed:
- Bedside respiratory function tests to rule out airway obstruction
- Chest x-ray in order to rule out ARDS
- Carboxyhemoglobin levels
- End-tidal CO2 (ETCO2), serum lactate
- Flexible fiberoptic laryngoscopy: may reveal laryngeal edema
- Flexible fiberoptic bronchoscopy: mucosal erythema and edema, blistering, ulceration and/or soot deposition
- Treatment: intubation and high flow oxygen therapy
- Prognosis: Resolution often occurs spontaneously within 2–3 days.
- Definition: a metabolic phenomenon that can occur in patients with moderate to severe burn injuries and is characterized by an initial hypometabolic phase followed by a hypermetabolic state
- Pathophysiology: An increase in catecholamines, cortisol, and inflammatory cytokines → severe metabolic alterations
- Hypometabolic phase (ebb phase)
- Onset within 48 hours of the burn injury
- Decreased cardiac output, oxygen consumption, and metabolic rate
- Hypermetabolic phase (flow phase)
- Hypometabolic phase (ebb phase)