Burn Care Procedures

Estimating Burn Depth

The depth of a burn has historically been classified by degree. First degree involves the epidermis only, second-degree (or partial-thickness) burns extend into the dermis, and third-degree (or full-thickness) burns destroy the entire skin. An additional fourth degree is sometimes used to describe injuries to the underlying muscle, tendon, or bone ( Fig. 38.2 ).

First-degree burns involve the epidermis only ( Fig. 38.3 A ). The skin is reddened but is intact and not blistered. This injury ranges from mildly irritating or even pruritic to exquisitely painful. Minor edema may be noted. Causes include ultraviolet light (as in sunburn) and brief thermal “flash” burns. First-degree burns may blister within 24 to 36 hours, and the patient should be warned about this possibility. Frequently, the epidermis may flake or peel within 5 to 10 days. Healing occurs spontaneously, usually without scarring.

Second-degree burns involve the epidermis and extend into the dermis to include the sweat glands and hair follicles. Superficial second-degree burns involve only the papillary dermis (see Fig. 38.3 B ) . These burns are pink, moist, and extremely painful. Blisters are common and the skin may slough. The burn blanches with pressure, and mild to moderate edema is common. Hair follicles often remain intact. Superficial second-degree burns are the most common burns seen in the emergency department (ED). The usual causes are scalds, contact with hot objects, or exposure to chemicals. Barring infection or repeated trauma, these burns heal spontaneously and without scarring in approximately 2 weeks. These areas may be sensitive to sunburn, windburn, and skin irritation for months after the original injury has healed.

Deep second-degree burns involve the reticular dermis and appear mottled white or pink (see Fig. 38.3 C ). There is obvious edema and sloughing of the skin, and any blisters are usually ruptured. Blanching is absent. These burns are not generally painful initially and may have decreased sensation, but pressure may be perceived. Within a few days, however, these burns can become exquisitely painful. This type of burn may be converted to a full-thickness injury by further trauma or infection.

Third-degree burns result from complete loss of the dermis and may extend into subcutaneous (SQ) tissue (see Fig. 38.3 D ) . These burns usually appear dry, pearly white, or charred. They are initially painless, with a leathery texture. Circumferential third-degree burns on an extremity or the torso cause a loss of elasticity that may impair the circulation or ventilation and necessitate an escharotomy.

Fourth-degree burns extend deeply into SQ tissue, muscle, fascia, or bone (see Fig. 38.3 E ) . These burns are characteristically caused by contact with molten metal, flame, or high-voltage electricity.

A more practical method of classifying burns is to describe them as either superficial or deep because this approach defines both treatment and prognosis. In general, first- and second-degree burns are considered partial-thickness burns, whereas third- and fourth-degree burns are full-thickness burns. As such, superficial burns involve the papillary dermis, with its rich vascular plexus, and the epidermis, which permits spontaneous healing by reepithelialization from the dermal appendages, including hair follicles, sebaceous glands, and sweat glands. This usually occurs within 2 weeks with minimal scarring. Superficial burns appear wet, pink, and blistered and blanch with pressure. They are painful. Deep burns involve the reticular dermis and SQ fat and generally lack sufficient epithelial appendages for spontaneous healing. If healing does occur, it will occur slowly and produce unstable skin, hypertrophic scarring, and contracture. Deep burns are best treated by excision and skin grafting. The initial appearance of deep burns ranges from cherry red, mottled, white, and nonblanching to leathery, charred, brown, and insensate ( Table 38.2 ).

Although bedside evaluation of very superficial or deep wounds presents little diagnostic difficulty, clinical assessment of a mid-dermal or “indeterminate” burn is accurate only approximately two-thirds of the time. Even though it is useful to initially characterize the extent of the burn, it must be noted that the early appearance of a burn wound may not accurately reflect the true extent of the soft tissue injury. Reexamination and follow-up are critical because burn wounds may change during the 24 to 72 hours following injury. Indeterminate burns may eventually heal spontaneously, or they may convert to deeper wounds requiring excision and skin grafting (see Fig. 38.1 ).

Estimating Burn Size

Calculating burn size is necessary to determine treatment plan, fluid requirements, and aids in prognosis. It is important for the emergency provider to accurately estimate the burn size. Note that first-degree burns do not count in the calculation of total burn surface area when utilizing fluid resuscitation formulas. Overestimating the burn size is a common error, especially in children. Several formulas are available to estimate TBSA in burn patients. In 1944, Lund and Browder published the now famous Lund-Browder chart ( Fig. 38.4 ). In their landmark paper, they used direct measurements and body surface area formulas to produce a chart that clinicians can use to estimate %TBSA. Burn centers typically utilize the Lund-Browder chart for estimating burn size. The initial Lund-Browder chart was developed from human anatomic studies derived from 11 adults (3 women and 8 men) and produced a unisex chart. A 2004 study involving 60 volunteers determined that the Lund-Browder chart significantly underestimates the size of chest burns in large-breasted women. The investigators developed a table that incorporates a correction using brassiere cup size.

The simplest method for estimating TBSA in adults is the “rule of nines.” This formula was developed in the late 1940s by Pulaski and Tennison, who observed that the percentage of each body segment was approximately a multiple of nine ( Fig. 38.5 ). Similar formulas for children adjust estimates for their disproportionately large head surface area. However, in a study of obese patients it was determined that this formula underestimates %TBSA of the legs and torso and overestimates %TBSA of the arms and head. The authors suggested replacing the “rule of nines” with a “rule of fives” for obese patients heavier than 80 kg.

The size of a burn can also be estimated by using the patient's hand as representing approximately 1% TBSA. With this method, the hand is a rectangle. However, two studies using planimetry have determined that the hand actually represents from 0.5% to 0.78% of a patient's TBSA.

Regardless of the method used, it is important for the emergency provider to take time to quantify the %TBSA as accurately as possible. It should be reemphasized that fluid recommendations based on %TBSA DO NOT include first-degree burns in the %TBSA, rather they are based on %TBSA of second- and third- (and fourth-) degree burns. Including first-degree burns in the calculation of %TBSA results in an overestimate of the total burned areas, and is a common error.

Emergency Treatment

Home or field treatment and ED care overlap. Initial treatment of a thermal injury begins immediately following the burn. If safe to do so, patients should be rapidly removed from the source of injury. Flames are extinguished by smothering the fire with a blanket, jacket, or equivalent item; by dousing the fire with water; or by using a chemical fire extinguisher. Most chemical injuries are best treated by irrigating the affected area with copious quantities of clean water. Patients with electrical injuries are removed from contact with the electrical source as soon as it is safe to do so.

Cooling is most beneficial for small burns if started within 3 minutes of injury and possibly of additional benefit if continued for the first few hours after the burn. Doing so has been shown to reduce pain significantly and can limit tissue damage by decreasing thromboxane production. When cooling a burn wound, it is important to avoid hypothermia or freezing of tissue because this may deepen the injury. At home or in the field, room-temperature or cold tap water irrigation, immersion, or compresses (20°C to 25°C) will provide some pain relief without the risk of further injuring burned tissues and inducing hypothermia, which can occur with iced solutions ( Fig. 38.8 ). Placing ice on a burn should not be done. Sterile dressings are not required for field treatment; a moist towel or nonadherent sheet may be used. Nonmentholated shaving cream makes an excellent temporary covering for out-of-hospital use if a dressing is not available. Home remedies, such as butter or Vaseline, are best avoided but are probably benign. Remove jewelry and gross debris in the field if possible.

Initial Care of Major Burns

Major burns require the specialized resources of a burn center. In such cases, emergency providers should initiate the resuscitation, consult the burn center for referral, and transfer the patient as soon as practically possible. Initial resuscitation should follow standardized trauma protocols, including a primary and secondary survey, and provide immediate interventions directed at airway management, breathing, and cardiovascular support, as needed. IV catheters can be inserted initially through burned skin when unburned sites are unavailable. Early IV access permits the administration of resuscitative fluids, medications, and parenteral narcotics to relieve the pain. Patients with burns exceeding 20% TBSA should receive IV fluid resuscitation with lactated Ringer's (LR) solution based on various available formulas. LR solution is preferred because large saline infusions will produce hyperchloremic acidosis. One need not use bolus fluid resuscitation as fluids are lost via capillary leak and via the raw skin, and significant fluid loss does not occur within the first hour.

Historically, the Parkland or Brooke formulas have been used to estimate fluid needs. It should be noted that the 2011 Advanced Burn Life Support (ABLS) Manual specifies that research has shown that the Parkland formula's 4 mg/kg × %TBSA formula commonly results in excessive edema formation and over-resuscitation. Whether this is because first-degree burns may have been erroneously included in the %TBSA or other reasons is unclear. For adults the ABLS advises a total of 2 mL LR × body weight in kilograms × % second- and third-degree burns in the first 24 hours. For pediatric patients (under age 14 and weight less than 40 kg), the ABLS advises a total of 3 mL LR × body weight in kilograms × % second- and third-degree burns in the first 24 hours. It should be noted that 24 hours starts at the time of the burn and not the time medical care begins. After the total amount is calculated, fluids should be administered as a constant infusion rather than by bolus administration. Half of the calculated fluid requirement should be given in the first 8 hours and the remaining half provided over the following 16 hours ( Box 38.2 ). Lastly, these fluid quantities are guidelines and urine output monitoring will assist in adjusting the rate or volume to meet the target outputs of 0.5 mL/kg per hour for adults and 1 mL/kg per hour for children weighing under 40 kg. According to the ABA, Foley catheter placement is advised in major burns to accurately monitor urine output.

More recently, the US Army Institute of Surgical Research has advocated a simpler formula for estimating hourly fluid requirements in burn patients. This simpler formula may be more useful for prehospital providers or ED resuscitation ( Box 38.3 ). The formulas estimate hourly fluid requirements and must be adjusted up or down to achieve a urine output of 0.5 to 1.0 mL/hr. Insertion of a Foley catheter is usually necessary to accurately measure hourly urine output.

Patients exposed to carbon monoxide should have carboxyhemoglobin levels measured and empirically receive 100% oxygen. The duration of oxygen administration will depend on the level and symptoms of the individual patient, but often require 6 hours or more. Once considered a traditional empirical treatment, there is no evidence-based proven benefit from hyperbaric oxygen therapy for carbon monoxide poisoning. A Cochrane review ( http://www.summaries.cochrane.org/CD002042 ) concluded that there is insufficient evidence to support the use of hyperbaric oxygen for the treatment of patients with carbon monoxide poisoning. The Cochrane review of published trials found conflicting, potentially biased, and generally weak evidence regarding the usefulness of hyperbaric oxygen for the prevention of neurologic injury. Per an evidence-based analysis, existing randomized trials do not establish whether the administration of hyperbaric oxygen to patients with carbon monoxide poisoning reduces the incidence of adverse neurologic outcomes. Because there may still be advocates of hyperbaric oxygen therapy, consultation with a local hyperbaric center is reasonable in certain cases, but it is not standard that this intervention be routinely implemented. Critically ill and pregnant patients are still often offered hyperbaric treatment, but controversy over the efficacy and safety persists even for these subgroups.

Cyanide is released from mattress fires and burning of upholstery. Patients suspected of having been exposed to significant levels of cyanide and manifesting symptoms should receive hydroxocobalamin (Cyanokit [Meridian Medical Technologies, Inc., Columbia, MD]). If not available, the Cyanide Antidote Package may be used despite lack of proven benefit of this traditional cyanide therapy. It is reasonable to empirically administer hydroxocobalamin or the sodium thiosulfate portion of the cyanide kit to burn victims in coma or to those exhibiting metabolic (lactic) acidosis after smoke exposure.

In addition to the logical increased mortality with larger areas of TBSA involved, the mortality of patients with burns is also increased when concomitant inhalation is present. The Baux Score was developed a half-century ago by Professor Serge Baux to estimate the mortality of burns. This score was updated in 2010 using data from the National Burn Registry to include the effect of inhalation injury to mortality ( Box 38.4 ). In short, the original Baux score became outdated because advances in care of the burn victim which has improved the mortality of patients. The modified Baux score is now more accurate for modern burn survival rates.

Box 38.4

From Baux S: Contribution a l'Etude du traitment local des brulures thermigues etendues , Paris, 1961, These; Osler, et al: Simplified estimates and probability of death after burn injuries: extending and updating the Baux score, J Trauma Inj Crit Care 68(3):690–697, 2010.

Baux Score and Modified Baux Score to Predict Mortality in Burn Injury

• Original Baux Score: % Mortality = Age + %TBSA

• Modified Baux Score: % Mortality = Age + %TBSA + 17*(Inhalation Injury, Yes=1, No=0)

Burn patients have an impaired ability to regulate their core body temperature and will quickly become hypothermic if untreated. Core temperature should be measured frequently, and active and passive warming strategies should be implemented to prevent hypothermia from developing. This can include minimizing exposure by covering patients with sheets and blankets, warming IV fluids, warming the room, or applying radiant or convective warming systems. In anticipation of transfer to a burn center or before surgical consultation, remove any wet cooling dressings that may have been applied initially and cover the wounds with dry gauze dressings.

Initial Care of Minor Burns

Prompt cooling of the burned part is an almost instinctive response and is one of the oldest recorded burn treatments, having been recommended by Galen ( ad 129–199) and Rhazes ( ad 852–923). In the ED, room-temperature or cold tap water irrigation, immersion, or compresses (20°C to 25°C) are optimal in obtaining pain relief and providing some measure of protection for burned tissues without the problems of hypothermia that iced solutions can cause. If not done before ED treatment, immediate cold water immersion may still have some ability to limit the extent of a burn and will provide significant pain relief. It is acceptable to add a few ice chips to the water, but packing the wound in ice must be avoided.

All involved clothing and jewelry (such as rings), along with any gross debris, should be removed from the burned area. Chemical burns involving the skin or eyes require prolonged tap water irrigation. The burn should otherwise be covered with a moist, sterile dressing. In the ED and prehospital phase, appropriate analgesics, usually narcotics, are the best way to control pain and should not be forgotten in the initial phase of burn care. The burned area may be immersed immediately in room-temperature water or covered with gauze pads soaked in room-temperature water or saline (see Fig. 38.8 ). The gauze may be kept cool and moist to provide continued pain relief; the patient will let the clinician know when additional cooling is desired. Many clinicians use sterile saline for cooling, but it has no proven benefit over tap water, even when the skin is broken. It is acceptable to add ice chips to water or saline to lower the temperature. As stated previously, immersion of burned tissue in ice or ice water should be avoided because ice immersion increases pain and risks frostbite injury or systemic hypothermia.

The potential benefits of burn cooling are listed in Box 38.5 . Because most patients with minor burns seek medical attention after initial self-instituted prehospital cooling, it is unlikely that the clinician can favorably affect the burned tissue with any intervention in the ED. With the exception of pain relief and removal of debris, the primary benefits of burn cooling are probably experienced only if the burn is cooled promptly, within the first 3 minutes after injury, thus making home care important. Minor burns are considered tetanus prone, and tetanus toxoid should be administered if patients are unsure of their tetanus immunization status or when it has been more than 10 years since the last immunization. Nonimmunized patients should receive tetanus toxoid and immunization with subsequent boosters in accordance with current guidelines.

Outpatient Care of Minor Burns

Minor burns are generally those that will heal spontaneously and do not require surgery or specialized wound care. These wounds are not associated with immunosuppression or hypermetabolism, nor are they highly susceptible to infection, a quality associated with larger burns. Treated conservatively, most minor burns will heal without significant scarring. Many complications seen with minor burns are thought to result from overtreatment rather than undertreatment. Examples include the use of dry dressings that can adhere to newly forming skin and secondary infections from the overzealous use of topical or systemic antibiotics.

The most important characteristic of a dressing is that it controls fluids within the wound. Burn dressings that keep the surface of the wound moist and avoid pooling of fluids will speed healing. The best material for this purpose is a generous amount of simple dry gauze applied over a nonadherent dressing or topical preparation. The outer layer of dressing should be porous to permit evaporation of water from the absorbent dressing material. Some clinicians prefer to eschew a nonadherent portion of the dressing so that subsequent dressing removal aids in minor débridement. Wound preparation and basic bandaging should include the following steps ( Fig. 38.9 ):

• 1.

  Cleanse the burned area gently with a clean cloth or gauze and a mild antibacterial wound cleaner such as chlorhexidine, and irrigate the wound with saline or water. It is not necessary to shave the hair in or around the wound. There is no benefit to vigorously washing a minor wound with strong antiseptic preparations (such as povidone-iodine [Betadine, Purdue Products L.P., Stamford, CT] and others).

• 2.

  Although some authors recommend leaving blisters intact, most sources advise that providers débride blisters and sloughed skin initially by peeling the devitalized skin from the wound ( Fig. 38.10 A–C ). Blisters can be opened with scissors and forceps. If necessary, provide analgesia for any painful débridement. On the initial débridement, attempt to remove only grossly devitalized tissue. Additional débridement of the wound can take place, if needed, during subsequent follow-up visits when the wound has matured.

  

• 3.

  Consider applying a layer of antibiotic cream or ointment such as 1% silver sulfadiazine (Silvadene [Pfizer Inc., New York, NY]) or bacitracin directly to the wound (see Fig. 38.10 D ).

• 4.

  Apply fine-mesh gauze or commercial nonadherent gauze such as Adaptic or petrolatum gauze impregnated with 3% bismuth tribromophenate (Xeroform [DeRoyal, Powell, TN]) to the burn wound.

• 5.

  Cover and pad the wound with loose gauze fluffs. If fingers and toes are involved, pad the web spaces and the digits individually and separate them with strips of gauze (see Figs. 38.9 D and 38.10 E and F ). Wrap the entire dressing snugly (but not tightly) with an absorbent, slightly elastic material such as Kerlix (Medtronic, Minneapolis, MN).

• 6.

  Instruct the patient to elevate the affected limb to prevent swelling, which may cause delayed burn conversion or wound infection.

Specific Clinical Issues in Minor Burn Care

Analgesia

Pain is a critical feature of any burn injury. Relief of pain by the appropriate and judicious use of narcotic analgesics is of the utmost importance in the initial care of all burn patients. Prehospital narcotics are very appropriate when standard contraindications do not exist. Analgesia should be provided before extensive examination or débridement is performed. Inadequate analgesia is probably the most common ED error in the treatment of burn injuries, especially when burns occur in children. Parenteral narcotic analgesics have been erroneously relegated to pain control only for major burns, but it is suggested that narcotics be generously administered in the initial treatment of even minor painful burns.

Parenteral opioids (e.g., fentanyl, 1 to 2 µg/kg, or morphine, 0.1 to 0.2 mg/kg) are usually required, especially if painful procedures such as débridement and dressing changes are planned. We prefer to use IV opioids (occasionally supplemented with a short-acting benzodiazepine such as midazolam) for all painful procedures. For complicated débridement or dressing changes adequate analgesia is a minimum requirement with some patients requiring procedural sedation (see Chapter 33 ).

Regional or nerve block anesthesia is an excellent alternative when practical, and if feasible, nitrous oxide analgesia may be used. Ketamine may also be a reasonable alternative. Oral opioids may be inadequate for the initial treatment of significant pain but can be used for continued outpatient analgesia. Local anesthetics may be injected in small quantities when appropriate, such as for the débridement of a deep ulcer or other small burn. Topical analgesics have no role in burn care. A properly designed dressing will do much toward preventing further discomfort after release home; however, home burn care and dressing changes may be quite painful. For this reason, an adequate supply of an oral opioid analgesic should be provided, and responsibility in analgesic use should be encouraged.

Pruritus

Postburn pruritus is one of the most common and distressing complications of burn injury and is estimated to affect 87% of burns. It typically develops in the subacute phase and is therefore not a common issue for the emergency provider in the acute treatment phase. Despite the limited literature on the treatment of postburn pruritus, available therapies include oral antihistamines, topical antihistamines, and topical moisturizers. The use of topical therapies should be withheld until sufficient wound healing has occurred.

Edema

Minor burns lead to immediate inflammation mediated by the release of histamine and bradykinins, which cause localized derangements in vascular permeability with resultant burn wound edema. This edema may be harmful in several ways. First, the increase in interstitial fluid increases the diffusion distance of oxygen from capillaries to cells and thereby increases hypoxia in an already ischemic wound. Second, the edema may produce untoward hemodynamic effects by a purely mechanical mechanism: compression of vessels in muscular compartments. Third, edema has been associated with the inactivation of streptococcicidal skin fatty acids, thus predisposing the patient to burn cellulitis.

Successful management of burn edema hinges on immobilization and elevation. Most patients are unfamiliar with the medical definition of elevation and are not aware or convinced of its value. Patient education in this regard is critical; however, certain burns (e.g., burns in dependent body areas) are prone to edema despite everyone's best intentions. It is for this reason that lower extremity burns in general and foot burns in particular are prone to problems. Major burns of the hand should be elevated while the patient is still in the ED. This is most readily accomplished by hanging the injured hand from an IV pole with a stockinette to support the bandaged hand ( Fig. 38.11 ).

Use of Topical Preparations and Antimicrobials

Minor burns result in insignificant impairment of normal host immunologic defenses, and burn wound infection is not usually a significant problem. Topical antimicrobials are often used; however, some believe that these agents may actually impair wound healing. Although the procedure is of unproven value, many clinicians routinely use antibiotic creams or ointments on even the most minor burns. Most patients expect some type of topical concoction, so a discussion of their use—or nonuse—is prudent.

Topical antimicrobials were designed for the prevention and care of burn wound sepsis or wound infection, primarily in hospitalized patients with major burns, and there is no convincing evidence that their use alters the course of first-degree burns and superficial partial-thickness injuries. As noted, the burn dressing is the key factor in minimizing complications in all burns. Nonetheless, topical antimicrobials are often soothing to minor burns, and their daily use prompts the patient to look at the wound, assess healing, perform prescribed dressing changes, or otherwise become personally involved in the care. Keep in mind that if a topical antimicrobial is used, its effectiveness is decreased in the presence of proteinaceous exudate, thus necessitating regular dressing changes if the antimicrobial benefit of topical therapy is to be realized. In reality, once-daily dressing changes are most practical and are commonly prescribed, and no data indicate that this regimen is inferior to more frequent dressing changes.

All full-thickness burns should receive topical antimicrobial therapy because the eschar and burn exudate are potentially good bacterial culture media and deep escharotic or subescharotic infections may not be easily detected until further damage is done. All deep partial-thickness injuries likewise benefit from the application of a topical antimicrobial. As stated, this intervention can await definitive therapy in a burn unit.

Criteria for choosing a specific topical agent include its' in vitro and clinical efficacy, toxicity (absorption), superinfection rate, ease and flexibility of use, cost, patient acceptance, and side effects. It is important to note that no firm scientific data convincingly support the use of any specific topical antimicrobial for minor outpatient burns.

Specific Topical Agents

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