Burns

A Look at Burns

A major burn is a serious injury, requiring painful treatment and a long period of rehabilitation. Destruction of the epidermis, dermis, or subcutaneous layers of the skin can affect the entire body as well as the patient's self-image. In many cases, the burn can be life-threatening. If not fatal, a burn can be permanently disfiguring and incapacitating, both emotionally and physically.

Disrupting duties

Like any injury to the skin, a burn interferes with the skin's main functions of keeping out infectious organisms, maintaining fluid balance, and regulating body temperature. Burn injuries cause major changes in the body's fluid and electrolyte balance. Many of those imbalances change over time as the initial injury progresses.

The extreme heat from a burn can be severe enough to completely destroy cells. Even with a lesser injury, normal cell activity is disrupted. With minimal injury, the cell may eventually recover its function. The burn patient's prognosis depends on the size and severity of the burn.

Several factors determine the severity of a burn, including the cause, degree, and extent of the burn as well as the part of the body involved. The outcome for a patient who has been burned is also affected by the presence of preexisting medical conditions and state of health.

Types of burns

Burns can result from thermal or electrical injuries or from exposure to chemicals, radiation, and friction.

Thermal burns

Thermal burns, which are the most common type of burns, result from exposure to either dry (flames) or moist (steam, hot liquids) heat. They commonly occur with residential fires, arson, motor vehicle accidents, childhood accidents, exposure to improperly stored gasoline or space heaters, or electrical malfunctions. Other causes may include the improper handling of fireworks, contact with scalding liquids, hot tar, and kitchen accidents.

Because its effects are similar to those of a thermal burn, frostbite is included in this category.

Electrical burns

Electrical burns occur after contact with faulty electrical wiring, high-voltage power lines, or immersion in water that has been electrified. These injuries may also be caused by lightning strikes. An electrical burn that ignites the patient's clothing may cause thermal burns as well.

Friction burns

Friction burns are on the rise, especially in the toddler age group due to toddlers getting their hands and forearms trapped under moving treadmills (Stiles, K., 2018).

Hidden hurt

When caring for a patient with an electrical burn, keep in mind that there may be more damage internally than meets the eye. Check the patient for entrance and exit wounds, and monitor for cardiac dysrhythmias. Tissue damage from an electrical burn is important to assess because internal destruction along the conduction pathway is usually greater than the surface burn indicates.

Chemical and radiation burns

Chemical burns result from the direct contact, ingestion, inhalation, or injection of acids, alkalies, or vesicants. These chemicals destroy protein in tissues, leading to necrosis. The type and extent of damage caused depends on the properties of the particular chemical involved in the burn. Alkali burns tend to be more serious due to deeper penetration into the tissue by a process called liquefaction necrosis (Schaefer & Szymanski, 2021).

Radiation burns are typically associated with sunburn (ultraviolet radiation), radiation treatment for cancer, and in people who have been exposed to excessive radiation from diagnostic procedures (Rice & Orgill, 2017).

Classification of burns

Burn thickness affects cell function. Therefore, classifying the degree of a burn helps to determine the type of intervention needed.

Superficial

Superficial burns (e.g., sunburns) affect the outermost layer of the epidermis. These burns are usually pink or red, dry, and painful. They blanch with pressure. No blistering occurs with this burn; however, some edema may be present. These burns aren't classified as severe because the epidermis remains intact and continues to prevent water loss from the skin, so they don't affect fluid and electrolyte balance. Regrowth of the epidermis occurs, and healing is generally rapid without scarring.

Partial thickness

Superficial partial-thickness and deep partial-thickness burns affect the epidermis and part of the dermis. These burns are caused by brief exposure to flames, hot liquids or solids, dilute chemicals, or intense radiation.

Superficial partial-thickness burns are characterized by pain, redness, weeping, blanching with pressure, and blisters that generally form between the epidermis and dermis within 24 hours (Rice & Orgill, 2017). Deep partial-thickness burns extend into the deeper dermis, damaging hair follicles and glandular tissue. They are not painful unless pressure is applied, do not blanch, appear wet or waxy, and may vary in color from bright red to white (Rice & Orgill, 2017).

Full thickness

Full-thickness burns destroy the epidermis and the dermis and often injure subcutaneous tissue. These burns look dry and leathery, are painless (because nerve endings are destroyed), and don't blanch when pressure is applied. The color of the burned area varies from waxy white to black or charred. The dead dermis, called burn eschar, is often still intact.

Full-thickness burns require skin grafting and carry the greatest risk of fluid and electrolyte imbalance.

Extension to deep tissues

Burns that extend beyond the dermis and subcutaneous tissue to the muscle layer and can include tendon or bone are sometimes referred to as fourth-degree burns.

These burns are charred and hard and do not blanch. Surgery is required, but even so, patients who experience this type of burn have a poor prognosis.

Burn severity

The severity of a burn can be estimated by correlating the mechanism of injury, extent, depth, and location. Burns are categorized as severe, moderate, and minor. Assessment tools, such as the rule of nines (used for adults) or the Lund-Browder classification (used for adults or children), are used to estimate the percentage of body surface area involved in a burn. (See Estimating the extent of a burn.) According to Rice and Orgill (2021), the “palm method” may also be used: “Small or patchy burns can be approximated by using the surface area of the patient's palm. The palm of the patient's hand, excluding the fingers, is approximately 0.5 percent of total body surface area, and the entire palmar surface including fingers is 1 percent in children and adults.”

Severe burns

Severe burns, which require treatment in a specialized burn care facility, include:

partial-thickness burns covering more than 25% of an adult's body surface area or more than 20% of a child's body surface area
full-thickness burns covering more than 10% of the body surface area
burns on the hands, face, eyes, ears, feet, genitalia, or perineum
all inhalation burns
all electrical burns, including electrocution
burns complicated by fractures or other major trauma
all burns in patients with preexisting medical conditions that may complicate treatment or recovery or affect mortality.

Moderate burns

Moderate burns, which require treatment in a hospital (but not necessarily a burn care facility), include:

full-thickness burns on 2% to 10% of the body surface area, regardless of body size
partial-thickness burns on 15% to 25% of an adult's body surface area and 10% to 20% of a child's body surface.

Minor burns

Minor burns, which can be treated in an emergency department or on an outpatient basis, include:

full-thickness burns that appear on less than 2% of the body surface area, regardless of body size
partial-thickness burns on less than 15% of an adult's body surface area and 10% of a child's body surface area (although most children are transferred to a burn center).

Burn phases

Burn phases describe the physiologic changes that occur after a burn and include the fluid accumulation, fluid remobilization, and convalescent phases in burns, which are greater than 20% total body surface area. Burns affect many body systems and can lead to several serious fluid and electrolyte imbalances, which vary depending on the phase of the burn.

Resuscitation phase

The resuscitation phase occurs at the time of injury and continues for the first 24 to 48 hours thereafter (Ignatavicius et al., 2017). During this phase, fluid shifts from the vascular compartment to the interstitial space, a process known as third-space shift. This shift of fluids causes edema. Severe edema may compromise circulation and diminish pulses in the extremities.

Permeability and plasma

Because of the burn injury, capillary damage alters the permeability of the vessels. Plasma—the liquid and protein part of blood— escapes from the vascular compartment into the interstitium. Because less fluid is available to dilute the blood, the blood becomes hemoconcentrated, and the patient's hemoglobin level and hematocrit rise.

Because of the third-space shift (fluids moving out of the vascular compartment), hypovolemia occurs. Hypovolemia causes decreased cardiac output, tachycardia, and hypotension. The patient may experience a decline in mental status or develop shock or arrhythmias.

With the burn's damage to the skin surface, the skin's ability to prevent water loss is also decreased. As a result, the patient can lose up to 8 L of fluid per day or 400 ml/hour.

The kidneys try to cope

Diminished kidney perfusion causes decreased urine output. In response to a burn, the body produces and releases stress hormones (aldosterone and antidiuretic hormone), which cause the kidneys to retain sodium and water.

Uneasy breathing

Depending on the type of burn, a patient may have a compromised, edematous airway. Look for burns of the head or neck, singed nasal hairs, soot (blackness) in the mouth or nose, coughing, voice changes, mucosal burns, and stridor. You may hear crackles or wheezes over the lung fields. The patient may breathe rapidly or pant. Circumferential burns and edema of the neck or chest can restrict respirations and cause shortness of breath.

Tissue turmoil

Injured tissue releases acids that can cause a drop in the pH level of blood and subsequently lead to metabolic acidosis. Damage to muscle tissue in full-thickness burns and electrical burns results in release of myoglobin, which can cause renal damage and acute tubular necrosis. Myoglobin gives urine a darkened appearance.

The GI takes a hit

Hypovolemia can lead to decreased circulation to the GI system, resulting in paralytic ileus, symptoms of which include decreased or absent peristalsis and bowel sounds.

Stress-induced gastric ulcers, known as Curling ulcers, can develop in the antrum of the stomach or in the duodenum as a result of the intense physiologic stress associated with burn trauma. These ulcers can be observed by endoscopy approximately 72 hours after injury.

Curling ulcers are most likely caused during the resuscitation phase as a result of decreased blood flow to the stomach along with reflux of duodenal contents. Large amounts of pepsin are also released. The combined ischemia, pepsin, and acid can lead to ulceration.

Signs of Curling ulcer include bloody or coffee-ground emesis and occult blood in the stool. Histamine blockers and antacids are used to reduce gastric acidity and ulceration. These lesions usually heal once the patient recovers from the acute injury.

The body's metabolic needs also increase because of the burn injury, usually in proportion to the size of the burn wound. A negative nitrogen balance can occur as well as a result of tissue destruction, protein loss, and the body's stress response.

Unbalanced!

Many electrolyte imbalances can occur during the resuscitation phase because of the hypermetabolic needs and the priority that fluid replacement takes over nutritional needs during the emergent phase:

Hyperkalemia can result from massive cellular trauma, metabolic acidosis, or kidney failure. The condition develops as potassium is released into the extracellular fluid in the initial days following the injury.
Hypovolemia can occur as a result of fluid losses and fluids moving from the vascular space to the interstitial space. Lost fluid resembles intravascular fluid in composition and contains proteins and electrolytes.
Hyponatremia can result from increased loss of sodium and water from the cells. Large amounts of sodium become trapped in edematous fluid during the fluid accumulation phase. Aqueous silver nitrate dressings may also contribute to this electrolyte imbalance.
Hypernatremia can occur as a result of the aggressive use of hypertonic sodium solutions during fluid replacement therapy.
Hypocalcemia can occur because calcium travels to the damaged tissue and becomes immobilized at the burn site. That movement can occur 12 to 24 hours after the burn injury. It can also occur because of an inadequate dietary intake of calcium or inadequate supplementation during treatment.
Metabolic acidosis can develop as a result of the accumulation of acids released from the burned tissue. It can also occur as a result of decreased tissue perfusion from hypovolemia.
Respiratory acidosis can result from inadequate ventilation, as happens in inhalation burns.

Acute phase

The acute phase starts about 36 to 48 (or more) hours after the initial burn. During this phase, fluid shifts back to the vascular compartment. Edema at the burn site decreases, and blood flow to the kidneys increases, which promotes urine output. Sodium is lost through the increase in diuresis, and potassium either moves back into the cells or is lost through urine.

Shifty business

Fluid and electrolyte imbalances present during the initial phase after a burn can change during the resuscitation phase. Here's a rundown of these imbalances:

Hypokalemia can develop as potassium shifts from the extracellular fluid back into the cells. The condition usually occurs 4 to 5 days after a major burn.
Hypervolemia can occur as fluid shifts back to the vascular compartment. Excessive administration of IV fluids may exacerbate the condition.
Hyponatremia may occur when sodium is lost during diuresis.
Metabolic acidosis can occur when loss of sodium results in the depletion of bicarbonate.

Rehabilitative phase

The rehabilitative phase begins after the acute phase resolves and ends when the patient achieves the highest level of functioning possible (Ignatavicius et al., 2017). During this phase, the focus is on the healing or reconstruction of the burn wound and the psychosocial needs of the patient as the patient adjusts to an altered appearance and/or altered abilities. Although the major fluid shifts have been resolved, further fluid and electrolyte imbalances may continue as a result of inadequate dietary intake. Anemia commonly develops at this time because severe burns typically destroy red blood cells.

What tests show

Diagnostic test results you may see when caring for a patient with burns include:

increased hemoglobin levels and hematocrit
increased serum potassium levels
decreased serum sodium levels
decreased serum calcium levels
increased blood urea nitrogen and creatinine levels, indicating kidney failure
low pH and bicarbonate levels, indicating metabolic acidosis
increased carboxyhemoglobin levels, indicating smoke inhalation
electrocardiogram (ECG) changes reflecting electrolyte imbalances or myocardial damage
myoglobin in the urine.

Edema alert!

Watch for signs and symptoms of pulmonary edema, which can result from fluid replacement therapy and the shift of fluid back to the vascular compartment. Check for decreased hemoglobin levels and hematocrit due to hemodilution from that fluid shift.

Inspect for infection

Skin impairment can lead to body temperature alterations and chills as well as infection. Blisters, charring, and scarring may appear, depending on the type and age of the burn. You may note a foul odor and purulent drainage coming from infected wounds.

How they're treated

Priorities in treating a burn patient reflect ABCs—airway, breathing, and circulation. Although current cardiopulmonary resuscitation (CPR) guidelines focus on circulation, airway, breathing (CAB) in that order, burn patients need to be cared for in the order of ABC. For a patient with severe facial burns or suspected inhalation injury, treatment to prevent hypoxia includes endotracheal (ET) intubation, administration of high concentrations of oxygen, and positive-pressure ventilation. Be aware that acute respiratory distress syndrome may develop from the body's immune response to injury and fluid leakage across the alveolocapillary membrane.

Let it flow, let it flow, let it flow

Fluid resuscitation is a vital part of burn treatment. Several formulas have been created to guide initial treatment for patients with burns. The Parkland formula is one of the more commonly used formulas. (See Fluid replacement formula.)

Initial treatment includes administration of lactated Ringer solution through a large-bore IV line to expand vascular volume. This balanced isotonic solution supplies water, sodium, and other electrolytes; it can help correct metabolic acidosis because the lactate in the solution is quickly metabolized into bicarbonate.

Colloid and more

Hypertonic solutions called colloids may be used to increase blood volume. Colloids draw water from the interstitial space into the vasculature. Patients who may benefit from colloid solutions are those requiring lower volume resuscitation such as preexisting heart disease, geriatric patients, and inhalation injuries. Examples of colloid solutions are plasma, albumin, and dextran.

A solution of dextrose 5% in lactated Ringer is typically reserved as a maintenance dose for children to prevent life-threatening hypoglycemia. Dextrose 5% in water may be used to replace normal insensible water loss as well as water loss associated with damage to the skin barrier after the first 24 hours. Central and peripheral IV lines are inserted as necessary. Potassium may be added to IV fluids 48 to 72 hours after the burn injury.

An indwelling urinary catheter permits accurate monitoring of urine output. Administration of morphine IV as ordered alleviates pain and anxiety. The patient may need a nasogastric (NG) tube to prevent gastric distention from paralytic ileus, along with histamine blockers and antacids to prevent Curling ulcers.

A booster of tetanus toxoid should be given I.M. for patients with any burn more serious than superficial thickness; if a patient has not completed a primary immunization series, tetanus immune globulin should be given (Rice & Orgill, 2017). Prophylactic antibiotics are not recommended because overuse of antibiotics fosters the development of resistant bacteria.

Treatment tips

Treatment of a burn wound includes:

initial debridement by washing the surface of the wound area with mild soap
sharp debridement by a health care provider of loose tissue and blisters because blister fluid contains vasospastic agents that can worsen tissue ischemia
coverage of the wound with an antibacterial agent, such as silver sulfadiazine (Silvadene) and an occlusive cotton gauze dressing
removal of eschar (escharotomy) by a health care provider if the patient is at risk for vascular, circulatory, or respiratory compromise. For example, if the patient has a circumferential burn that circles around an extremity, the chest cavity, or the abdomen, skin grafts may also be required. If the patient is going to be transferred to a burn center, defer to the patient treatment criteria prior to transfer. Most burn centers request that no antibacterial agent is applied to the burn but require dry dressings applied to the wound.

How you intervene

For a patient with a burn injury, proper intervention and evidence-based nursing care can make the difference between life and death. During the resuscitative phase, immediate, aggressive burn treatment to increase the patient's chance for survival takes first priority. Later, the priority shifts to providing supportive measures and using strict aseptic technique to minimize the risk of infection. (For tips on how to handle burns outside the health care system, see Emergency burn care.)

Here are some general burn care guidelines:

Maintain head and spinal alignment until head and spinal cord injuries have been ruled out.

Shocking situation

Give emergency treatment for electric shock if needed. If an electric shock caused ventricular fibrillation and subsequent cardiac and respiratory arrest, begin CPR at once. Try to obtain an estimate of the voltage that caused the injury.
Make sure the patient has an adequate airway and effective breathing and circulation. If needed, assist with ET intubation. The patient may have a tracheostomy tube inserted if ET intubation isn't possible. Administer 100% oxygen as ordered, and adjust the flow to maintain adequate gas exchange. Draw blood for arterial blood gas (ABG) analyses as ordered.
Assess vital signs every 15 minutes. Assess breath sounds, and watch for signs of hypoxia and pulmonary edema.
Take steps to control bleeding, and remove clothing that is still smoldering. Cut around clothing stuck to the patient's skin. Remove jewelry and any constricting items.
Assess the skin for the location, depth, and extent of the burn.
Assist with the insertion of a central venous line (check state Board of Nursing law and rule to practice within your scope) and additional arterial and IV lines.
Start IV therapy at once as ordered to prevent hypovolemic shock and maintain cardiac output. Follow the Parkland formula or another fluid resuscitation formula for calculation, as ordered by the health care provider.
Insert an indwelling urinary catheter as ordered, and monitor intake and output every 15 to 30 minutes.
Maintain adequate pulmonary hygiene by turning the patient and performing postural drainage regularly.
Watch for signs of decreased tissue perfusion, increased confusion, and agitation. Assess peripheral pulses for adequacy.
Assess the patient's heart and hemodynamic status for changes that may indicate fluid imbalances, such as hypervolemia or hypovolemia.
Observe the pattern of third-space shifting (generalized edema, ascites, and pulmonary or intracranial edema), and document your findings.
Monitor potassium levels, and watch for signs and symptoms of hyperkalemia, such as cardiac rhythm strip changes; weakness; diarrhea; and a slowed, irregular heart rate.
Monitor sodium levels, and watch for signs and symptoms of hyponatremia, such as increasing confusion, twitching, seizures, abdominal pain, nausea, and vomiting.
Assess for signs and symptoms of metabolic acidosis, such as headache; disorientation; drowsiness; nausea; vomiting; and rapid, shallow breathing.
Monitor oxygen saturation and ABG results.
Monitor all laboratory results.
Monitor ECG results for arrhythmias.
Anticipate the need to administer maintenance IV replacement fluids as ordered based on daily assessment of fluid, electrolyte, acid-base, and nutrition status.
Maintain core body temperature by covering the patient with a sterile blanket and exposing only small areas of the body at a time as needed.
Insert an NG tube, if ordered, to decompress the stomach. Avoid aspiration of stomach contents during the procedure.
Obtain a preburn weight from the patient or caregiver.
If bowel sounds are present, provide a diet high in potassium, protein, vitamins, fats, nitrogen, and calories to maintain the patient's preburn weight. Verify a preburn weight from the patient or caregiver. If necessary, feed the patient enterally until oral feedings can again be tolerated. If oral or enteral feedings cannot be tolerated, administer hyperalimentation as ordered.
Weigh the patient every day at the same time with the same amount of linen, clothes, and dressings.
Explain all procedures to the patient before performing them. Speak calmly and clearly to help alleviate anxiety. Encourage the patient to participate in self-care as much as possible. (See Teaching about burns.)
Use strict aseptic technique for all patient care, including routinely washing your hands and using protective equipment and isolation garb.
Observe the patient for signs of infection, such as fever, tachycardia, and purulent wound drainage. Patients with burn injury have an increased risk of infection from destruction of the skin barrier and the loss of nutrients.
Administer an analgesic 30 minutes before wound care.
Culture wounds before applying a topical antibiotic for the first time.
Cover burns with a dry, sterile dressing. Never cover large burns with saline-soaked dressings because they can drastically lower body temperature. A topical ointment and an antibiotic may be applied as ordered. Be aware that silver nitrate and mafenide acetate (Sulfamylon) can cause electrolyte imbalances and metabolic alterations.
Maintain joint function with physical therapy and use of supportive garments and splints.
Notify the health care provider of significant changes in the patient's condition and pertinent laboratory test results.
Provide opportunities for the patient to voice concerns, especially about altered body image. If appropriate, arrange a meeting with another burn patient with similar injuries or refer the patient to a burn support group. When possible, show the patient how bodily functions are improving. If necessary, refer for mental health counseling.
Prepare the patient and caregiver for discharge.
Document all care given, all teaching done, and the patient's reaction to each. (See Documenting burn care.)

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