- First-degree burn: A burn that involves only the epidermal layer of the skin.
- “Fourth-degree” burn: A burn that has pentrated the entire dermal layer of the skin and extended into muscle and bone tissue.
- Local response: Three zones of burns including the zones of coagulation, statis and hyperaemia.
- Second-degree burn: A burn that commonly involves blistering to the affected area, redness and severe pain.
- Systemic response: When a large area of the body (30% or more) is burned, the effects that involve cardiovascular, respiratory, metabolic and immunological changes.
- Third-degree burn: A burn that penetrates through the dermal layer of the skin.
- Identify the changes in anatomy and physiology caused by burns.
- Understand the damage caused by the three (or four) levels of burn severity.
- Know how to comprehensively assess and provide treatment to a burn patient’s specific needs.
A peaceful Sunday morning is transformed into a scene of chaos as a commercial structure bursts into flames from an intentionally set fire. Moments later, emergency vehicles from multiple fire stations arrive to find a local hardware store engulfed in the blaze. A woman waves frantically and points to an area of the store where a man is trapped inside. Firefighting crews swiftly conduct a search and emerge carrying a young man with multiple burns.
The Rescue 52 crew works swiftly to assess the ABCs (airway, breathing and circulation) to detect life threats. Soot is noted in the patient’s mouth and nose, and the patient’s voice is hoarse. High-flow humidified oxygen is provided through a non-rebreather mask as the patient is rapidly loaded into the ambulance.
En route to the hospital, IV access is established while another caregiver removes the patient’s clothing to assess the injuries. Partial thickness burns are noted to the anterior aspect of both upper extremities, and further examination reveals burns to the chest and abdomen. No other burns are discovered during the rapid trauma exam.
Using the rule of nines, the lead paramedic determines the second-degree burns encompass approximately 27% of the man’s body. The burns are dressed, and the patient’s body temperature preserved.
The paramedic prepares for intubation and closely monitors the airway status to detect signs of airway compromise. The pulse oximeter reads 99%, and the remaining vital signs are stable. While additional assessments are performed, the hospital is notified of the “trauma alert” patient, which activates a specialized crew of caregivers.
Within minutes, the ambulance arrives at the hospital and the patient is transferred to the ED that continues care until the patient is later transferred to a regional burn unit. Though it takes several months, the patient is able to make a full recovery. Had it not been for the coordinated effort of emergency workers, hospital staff and the burn care-unit team, the outcome could have been dramatically worse.
Figure 1: Layers of the skin. Illustration Brook Wainwright Designs
Anatomy & Physiology
Although burns can affect any part of the body, the primary area subjected to insult is the skin. The skin is the largest organ of the body and performs several critical functions, such as helping to regulate body temperature, providing a barrier to infection, serving as a sensory organ, storing water and fat, and preventing water loss.
The skin is comprised of identifiable layers, which include the epidermis (outermost layer), dermis (middle layer), and subcutaneous tissue (innermost layer). The epidermis has five of its own layers (the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale) that help serve as a barrier to infection, absorb Vitamin D from sunlight and give skin its pigment (melanin).
Directly beneath the epidermis is the dermal layer, which contains blood vessels, nerves, glands, connective tissue and hair follicles. Burns that penetrate into this region are painful and can interfere with the skin’s ability to help in regulating the body’s temperature. When uninjured, the sudoriferous (sweat) glands help to cool the body by producing fluid that help cool the body when it evaporates. The blood vessels found in the dermal layer help to control temperature by vasoconstricting to preserve core temperature and vasodilating to release heat from the body. A burn that penetrates into the dermis can compromise both of these mechanisms.
Lying below the dermis is the subcutaneous (hypodermis) layer, comprised of fat and connective tissue. Larger blood vessels and nerves can also be found in this layer of skin. The subcutaneous layer aids the body by functioning as a shock absorber, anchoring skin in position, and forms a layer of insulation to further aid in regulating body temperature. Fat deposited within the subcutaneous layer is an important energy reserve for the body.
Figure 2a: First-degree burn. Photo courtesy Edward T. Dickinson, MD
Figure 2b: Second-degree burn. Photo courtesy Edward T. Dickinson, MD
Exposure to thermal sources, chemicals, radiation and electricity can all cause burns. Each form of injury has unique considerations that will be discussed later in this article. Approximately 1 million burn injuries occur each year in the United States, while only 40,000 to 60,000 require admission to a hospital or burn center.1 Burn injuries can be broken down into two key categories—local response and systemic response.2
The local response includes three zones. The first is known as the zone of coagulation and is the area with the highest degree of injury. Typically, this area has irreversible tissue loss, owing to the coagulation of proteins that occurs as a result of the insult. Next is the zone of stasis, which surrounds the zone of coagulation. This zone represents “at risk” tissue that often suffers from decreased perfusion but can be saved with proper wound care. The final area impacted by a burn is the zone of hyperemia. This zone has increased tissue perfusion and is usually able to heal absent infection or other compromise.
Burns that affect a larger area of the body (30% or more) can result in systemic effects involving cardiovascular, respiratory, metabolic and immunological changes. Cytokines and other inflammatory mediators are circulated and cause changes in the body as a whole. The cardiovascular system can experience increased capillary permeability, decreased contractility of the heart, and hypotension arising from fluids lost as a result of the burn itself and fluid leaking from the vessels due to the increase in capillary permeability. Bronchoconstriction can also arise, which further compromises the patient’s ability to bring oxygen to the body’s cells. Metabolism dramatically increases as the immune system’s ability to respond to infection significantly declines. The collective effect of these systemic responses is an increased risk of complications.
Figure 2c: Third-degree burn. Photo courtesy Edward T. Dickinson, MD
Figure 2d: “Fourth-degree” burn. Photo courtesy Edward T. Dickinson, MD
Based on the offending mechanism of injury for the burn patient, the prehospital caregiver needs to take specific actions to reduce the risk of secondary injury to the patient while also decreasing the risk of provider injury. For example, the simple act of unplugging a charged electrical device or turning off a circuit breaker greatly reduces the risk of injury to the EMS provider and stops electrical current flowing into a patient.
Chemical burns pose unique hazards to the patient and emergency responder. A wide variety of chemicals can cause burns, including acids, alkalis and chemicals that yield an exothermic reaction. Scene safety will be a critical consideration whenever a chemical is the reason for a burn. Only trained providers should intervene. Actions to take include attempting to identify the product, ensuring that no other persons become exposed, and providing decontamination. Dry powders, such as lye, should be gently brushed off before decontamination occurs.
Thermal burns create a risk of injury to the prehospital caregiver. The case study presented a situation in which the prehospital worker would need to work in tandem with firefighting personnel to care for a thermal burn arising from a structure fire. Astute caregivers remain alert for unique injuries the patient may experience from being exposed to a structure fire or superheated steam. Soot in the mouth and/or nose, singed hairs, burns to the face, and/or a hoarse voice can be indicative of laryngeal edema, which can be life threatening.
While most burns arising from a radiological source will simply involve the sun, it’s possible a patient has become exposed to another more sinister radiological source. Radioactive sources can pose a great risk of harm to the prehospital caregiver. The responding crew must take steps to ensure it doesn’t become exposed to a radioactive source while simultaneously working to determine how to remove the patient from the offending agent. A specialized hazardous materials team may need to respond to assist.
Ensure the scene is safe prior to approaching the burn patient, then begin patient assessment with a team approach. One caregiver should perform the initial assessment to detect threats to life and correct threats as discovered. A-B-C-D-E can be used as to recall that the initial assessment includes examining the airway, breathing, circulation and disability, and that the patient should be exposed and examined. The second caregiver should assess the mechanism of injury to determine the cause of the burn.
Specific assessment of the burn itself includes determining both the depth of the burn as well as the impacted body surface area. Burn depth is classified into degrees. A first-degree burn involves only the epidermal layer while a second-degree burn (partial-thickness) involves the epidermis and dermis. A third-degree burn penetrates through the entire dermal layer and are known as full-thickness burns. Some authorities also use the term “fourth-degree” burn to denote one that has extended into muscle and bone tissue.3
First-degree burns are characterized by redness to the affected area with a sunburn as the typical example. Second-degree burns commonly involve blistering to the affected area, redness and severe pain. Third-degree burns can appear as black, charred skin, or the skin may appear white. The skin will typically be dry. While this type of burn is said to involve no pain due to the complete destruction of the skin layers, there’s often an accompanying second-degree burn that causes significant pain. Careful assessment on the part of the prehospital caregiver will reveal areas that have varying degrees. Lastly, the “fourth-degree” burn will extend all the way through the skin and involve deep connective tissue, muscle and/or bone.
Equally important to the determination of the depth of the burn is to determine how much of the body has been affected. A third-degree burn affecting only 1% of the upper extremity is not as serious in the prehospital setting as a second-degree burn that involves the upper extremities, chest and abdomen. Thus, the caregiver must consider both in determining a burn’s severity.
There are two popular methods for assessing the body surface area impacted by a burn—the “rule of nines” and the palmar method. The rule of nines is used to rapidly determine how much body surface area has been affected for a larger burn. For the adult, each upper extremity equates to 9%, each lower extremity is equal to 18%, the chest and abdomen together comprise 18% while the same area posteriorly is 18%, the head is 9%, and the remaining 1% is for the groin. A slight modification is made when a pediatric patient has been burned. A simple way to remember the difference between the adult and the pediatric patient rule of nines is to take 4.5% from each lower extremity and apply that amount to the head. Thus, the child’s head is 18%, and the lower extremities are approximately 14% for each.
The palmar method is used when a small burn is present. This technique involves using the palm of the patient’s hand as roughly 1% of the body surface area. A 4″x4″ gauze pad can often be folded in a shape that closely approximates the patient’s palm and then compared to the area burned to approximate the burn percentage.
Figure 3: Rule of nines. Illustration Brook Wainwright Designs
The first step in treating any burn is to stop the burning process. For example, the patient should be removed from the heat source. Jewelry should be removed unless it would cause additional injury to remove it. Gently remove any clothing from a burned area. If clothing adheres to the burn, leave it in place and cut around it. Smaller burns can be cooled with tap water or irrigation solution.4–7
Recall that larger burns can compromise the body’s ability to regulate its temperature, which increases the risk for hypothermia. Cooling the burn while preventing hypothermia may seem contradictory, but it’s an important aspect of care. Another treatment option to stop the burning process and provide a measure of pain relief is to use commercially available hydrogel-impregnated burn dressings.8
Pain relief is also a key consideration in caring for the burn patient. Smaller burns will be easier to manage, and the cooling process will often provide some measure of pain relief.
Medications administered in the prehospital setting vary widely by agency. Some entities opt to provide morphine sulfate in 2–5 mg increments for patients who have burns without systemic effects. Other options include patient self-administered nitrous oxide. Nalbuphine has also been shown to be a safe, effective agent for use in the prehospital setting.9
Patients with systemic effects from a large burn should be managed based on patient presentation. High-flow oxygen should be established early in the course of care. IV access should be accomplished using a large bore catheter inserted, when possible, at a site away from burns.
The Parkland formula can be used to determine the fluid resuscitation needs over a 24-hour period, with 50% given in the first eight hours and the remaining 50% infused over the following 16 hours.10 The patient is to receive (Lactated Ringer’s was the fluid recommended for this formula) 4 mL/kg per percentage of body surface area burned. Hypotension in the prehospital setting can be managed with infusions of saline or Lactated Ringer’s based on local protocol.
Prehospital caregivers need to remain alert for signs of laryngeal edema in patients exposed to fire or superheated steam. Early preparation for endotracheal intubation should be among the actions taken by the caregiver when the patient presents with soot in the mouth or nose, sebaceous sputum, singed nasal hairs, and/or a hoarse voice. Advanced providers may have standing orders that allow for the use of sedation and paralytic agents when signs of laryngeal edema are present. Rapid transport is always a high priority for this type of patient.
Rapid transport is especially important to burn patients with systemic effects from a large burn. Photo courtesy Robert Sheridan, MD/Shriners Hospital for Children
Prehospital caregivers play an important role in the assessment and treatment of burn patients. As with any other type of trauma, the focus should first be to detect threats to life and manage accordingly. Care for the burn includes stopping the burning process, cooling the burn when appropriate and providing relief of pain as local protocols allow. Systemic effects can be managed with high-flow oxygen and administration of fluids to counteract hypotension. While it may seem ironic, it’s important to prevent hypothermia in the patient who has encountered a significant burn.
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