Plastic surgery

PART II

SKIN AND SOFT TISSUE

CHAPTER 15  THERMAL, CHEMICAL, AND ELECTRICAL INJURIES

MATTHEW B. KLEIN

Few areas of medicine are as challenging medically and surgically as burn care. Burn injuries affect the very young and the very old, both men and women. Burn injuries can vary from small wounds that can be easily managed in the outpatient clinic to extensive injuries resulting in multiorgan system failure, a prolonged hospital course, and long-term functional and psychosocial sequelae.

According to the National Institutes of General Medical Sciences, an estimated 1.1 million burn injuries require medical attention annually in the United States. Of those injured, about 50,000 require hospitalization and about 4,500 die annually from burn injuries. Survival following burn injury has significantly improved over the course of the 20th century. Improvements in resuscitation, the introduction of topical antimicrobial agents, and, most importantly, the practice of early burn wound excision have all contributed to the improved outcome. However, extensive burn injuries remain potentially fatal.

BURN MANAGEMENT: OVERVIEW

Etiology

Burn injuries can result from a variety of causes. Scald burns are the most common cause of burn injury in the civilian population. The depth of scald burn is determined by the temperature of the liquid, the duration of exposure to the liquid (Table 15.1), and the viscosity of the liquid (there is usually prolonged contact with more viscous liquids). Scald burns with hot liquids will typically heal without the need for skin grafting. Grease burns, however, tend to result in deeper dermal burns and will occasionally require surgical management. Flame burns, the next most common cause of burn injury, typically result from house fires, campfires, and the burning of leaves or trash. If the patient’s clothing catches fire, burns will usually be full thickness. Flash burns are quite common as well and typically result from ignition of propane or gasoline. Flash burns will typically injure exposed skin (most commonly face and extremities) and usually result in partial thickness burns. Contact burns occur from contact with woodstoves, hot metals, plastics, or coals. Contact burns are usually deep but limited in extent of body surface area injured. In addition, burn injury can result from electrical and chemical agents as well.

Organization of Burn Care

The essence of successful burn care is the team. No individual is capable of meeting the many acute and long-term needs of the burn patient. Therefore, burn care is best delivered in a specialized burn center where experienced physicians, nurses, physical and occupational therapists, nutritionists, psychologists, and social workers can all participate in the care of the individual. With the exception of small burns, patients with burn injuries should be referred to a burn center. The American Burn Association has established formal criteria for transfer to a burn center (Table 15.2). It is important to consider these as only guidelines. Patients who do not have a local physician comfortable caring for even a minor burn should be transferred to the nearest burn center.

Evaluation of the Burn Patient

Once a patient arrives at the burn center, a thorough evaluation is performed so that an effective treatment plan can be initiated. It is important to remember that burn patients are trauma patients, and they require evaluation in accordance with the Advanced Trauma Life Support (ATLS) protocol. Airway, breathing, and circulation must be assessed immediately following a burn injury. In addition to ensuring a patent airway, adequate breathing, and circulation, the presence of additional injuries—particularly life-threatening injuries—requires exclusion.

A thorough history of the burn injury is critical as it may provide some important information that will ultimately affect management. Details related to the location of the injury (indoors vs. outdoors), type of liquid involved in a scald, duration of extraction from fire, as well as details of the patient’s other medical problems are all elements of an adequate history. Any child who has an injury that is suspicious for abuse should be admitted to the hospital regardless of burn severity so that social services can be contacted and the circumstances surrounding the injury investigated. Adults with burn injuries greater than 15% to 20% are admitted to an intensive care unit for adequate monitoring and infectious control. Smaller children or elderly patients with less extensive burn injuries are monitored in an intensive care setting. In addition, patients requiring close airway monitoring (i.e., suspected inhalation injury) or frequent neurovascular checks are placed in an intensive care unit setting.

Determination of Burn Extent. The extent and depth of burn wounds are established shortly following admission. The total body surface area (TBSA) burned is calculated using one of several techniques. When calculating TBSA, one includes those areas of partial and full thickness burns. Superficial burns are not included in the calculation. The rule of nines (Figure 15.1) is perhaps the best known method of estimating burn extent. However, it is important to note that the proportions of infants and children are different than those of adults. The head of children tends to be proportionately greater than 9% TBSA, and the lower extremities are less than 18%. In addition, it is important to explain to the inexperienced person that the percentage assigned to a body part represents a total area, so that a portion of an arm burn is only a portion of 9%. A second technique of estimating TBSA is using the patient’s hand. The patient’s hand represents about 1% TBSA and the total burn size can be estimated by determining how much of the patient’s (not the examiner’s) hand areas are burned. Lund and Browder charts are a more accurate method of assessing burn extent. They provide an age-based diagram to assist in more precisely calculating the burn size (Figure 15.2).

FIGURE 15.1. The Rule of 9’s provides a facile method of estimating total body surface area burned. Due to differences in body proportions, the percentage for each body area is different in adults and children.

Depth of Burn Injury. Thermal injury can injure the epidermis, a portion of or the entirety of the dermis, as well as subcutaneous tissue. The depth of the burn affects the healing of the wound, and therefore, assessment of burn depth is important for appropriate wound management and, ultimately, the decision for operative intervention. The characteristics of superficial, partial, and full thickness burns are described below and summarized in Table 15.3.

Superficial burns involve the epidermis only and are erythematous and painful. These burns typically heal within 3 to 5 days and are best treated with a topical agent such as aloe lotion that will accelerate healing and soothe the patient. In addition, oral analgesics can be helpful. Sunburns are the prototypical superficial burns.

FIGURE 15.2. The Lund and Browder chart provides a more precise estimate of burn TBSA for each body part based on the individual’s age.

Partial thickness burns involve the entirety of the epidermis and a portion of the dermis. Partial thickness burns are further divided into superficial and deep partial thickness based on the depth of dermal injury. Superficial and deep partial thickness burns differ in appearance, ability to heal, and potential need for excision and skin grafting. Superficial partial thickness burns are typically pink, moist, and painful to the touch (Figure 15.3). Water scald burns are the prototypical superficial partial thickness wound. These burns will typically heal within 2 weeks and will generally not result in scarring, but could result in alteration of pigmentation. These wounds are usually best treated with greasy gauze with antibiotic ointment.

Deep partial thickness burns involve the entirety of the epidermis and extend into the reticular portion of the dermis. These burns are typically dry and mottled pink and white in appearance and have variable sensation. If protected from infection, deep partial thickness burns will heal within 3 to 8 weeks, depending on the number of viable adnexal structures in the burn wound. However, they will typically heal with scarring and possible contractures. Therefore, if it appears that the wound will not be completely reepithelialized in 3 weeks time, operative excision and grafting is recommended.

Full thickness burns involve the epidermis and the entirety of the dermis. These wounds are brown-black, leathery, and insensate (Figure 15.4). Occasionally, full thickness burn wounds will have a cherry red color from fixed carboxyhemoglobin in the wound. These wounds can be differentiated from more superficial burns because they are usually insensate and do not blanch. Full thickness burns are best treated by excision and grafting, unless they are quite small (size of a quarter).

FIGURE 15.3. A superficial partial thickness scald burn is typically moist, pink, and tender. These burns will usually heal within 1 to 2 weeks.

Determination of burn depth is usually easy for superficial and very deep wounds. However, determining the depth of deep dermal burns and their healing potential can be more challenging. It often takes several days to determine whether these are wounds that will heal within 3 weeks or would be better managed with excision and grafting. A variety of techniques have been described for precise determination of burn depth including fluorescein dyes, ultrasound, laser Doppler, and magnetic resonance imaging. However, none of these methods have proven to be more reliable than the judgment of an experienced burn surgeon.

FIGURE 15.4. Full thickness burn wounds have a dry, leathery appearance and can vary in color from brown to black to white. Full thickness burns are insensate and will not blanch.

Initial Management

Intravenous Access. Intravenous access is important for patients who will require fluid resuscitation as well as for those patients who will require intravenous analgesia. Two peripheral IV lines are usually sufficient for patients with less than 30% burns. However, patients with larger burns or significant inhalation injury may require central line placement. Both peripheral and central lines can be placed through burned tissue when required. The burned area is prepared with topical antimicrobial solution as is done when preparing uninjured skin. Lines should be securely sutured in place, particularly over burned areas where the use of tape dressings is difficult. Typically, a triple lumen catheter is adequate access since large volume fluid boluses are not a standard component of burn resuscitation. Furthermore, there is usually no need for a pulmonary artery catheter introducer since these catheters are of little benefit, and carry certain complication risks, in the resuscitation of the burned patients. Arterial line placement is usually necessary in the patient who is intubated and is likely to remain intubated for several days.

Escharotomy. The leathery eschar of a full thickness burn can form a constricting band that compromises limb perfusion. It is important to determine if escharotomy is necessary. During fluid resuscitation the problem worsens because of swelling. In general, escharotomies are indicated for full thickness circumferential burns of the extremity or for full thickness burns of the chest wall when the eschar compromises thoracic cage excursion and, thus, ventilation of the patient. Escharotomy can be performed at the bedside using a scalpel or electrocautery. Adequate release occurs when the eschar separates, perfusion improves, and, on occasion, a popping sound is heard. The ideal location of escharotomy incisions is shown in Figure 15.5. It is important to avoid major superficial nerves when performing escharotomy. The incision should go through only eschar, not fascia. Incisions that are too deep can unnecessarily expose vital underlying structures such as tendons and also increase the chance of desiccation and death of otherwise healthy tissue.

Topical Wound Agents. Following admission to the burn center, the patient’s wounds are cleansed with soap and water. Loose tissue and blisters are debrided. Body and facial hair are shaved if involved in the area of a burn. Daily wound care is performed on a shower table with soap and tap water or, if the burn wound is small, at the patient’s bedside following a shower. The use of tanks for wound care has fallen out of favor because of the risks of cross-contamination.

Burn injury destroys the body’s protective layer from the environment and dressings are needed to protect the body from infection and minimize evaporative heat loss from the body. The ideal dressing if it existed would be inexpensive, easy to use, require infrequent changes, and be comfortable. While a number of topical agents are available for burn wound care, it is best to have a simple, well-reasoned wound care plan.

The choice of topical burn wound treatment is contingent on the depth of burn injury and the goals of management. Superficial burn wounds (such as sunburns) require soothing lotions that will expedite epithelial repair such as aloe vera. Partial thickness burn wounds need coverage with agents that will keep the wound moist and provide antimicrobial protection. Deeper partial thickness burn wounds should be covered with agents that will protect the eschar from microbial colonization. Once the eschar has lifted and the wound has begun to epithelialize, a dressing that optimizes epithelialization (i.e., greasy gauze and antibiotic ointment) is utilized. Full thickness burns are also covered with a topical agent that protects the burn wound from getting infected until the time of burn excision.

Prophylactic systemic antibiotics have no role in the management of burn wounds. In fact, the use of prophylactic antibiotics has been shown to increase the risk of opportunistic infection.1 Since burn eschar has no microcirculation, there is no mechanism for the delivery of systemically administered antibiotics. Therefore, topical agents need to provide broad-spectrum antimicrobial coverage at the site of colonization—the eschar.

FIGURE 15.5. The location of escharotomy incisions on the (A) upper extremity; (B) hand; and (C) lower extremity.

In the early postburn period, the dominant colonizing organisms are staphylococci and streptococci—typical skin flora. Over time, however, the burn wound becomes colonized with gram-negative organisms. Thus, topical antimicrobial agents used in early burn care should have broad-spectrum coverage to minimize colonization of the wound, but they need not penetrate the burn eschar deeply.

Silver sulfadiazine is the most commonly used topical antimicrobial agent. Silver sulfadiazine has broad-spectrum antimicrobial coverage, with excellent Staphylococcus and Streptococcus coverage. However, silver sulfadiazine is incapable of eschar penetration, so it is less useful in the management of the infected burn wound. Wounds treated with silver sulfadiazine will develop a yellowish-gray pseudoeschar that requires removal by cleansing during daily wound care. Traditionally, the principal drawback of silver sulfadiazine was thought to be leukopenia. However, it is not clear whether the leukopenia that occurs results from silver sulfadiazine toxicity or from the margination of leukocytes as part of the body’s systemic inflammatory response to the burn injury. Regardless, the leukopenia is typically self-limited, and therefore, the silver sulfadiazine should not be discontinued. Patients with a documented sulfa allergy may or may not have a reaction to the silver sulfadiazine. If there is concern about an allergy, a small test patch of silver sulfadiazine can be applied. Typically, if there is an allergy, the silver sulfadiazine will be irritating rather than soothing. In addition, a rash could signal a silver sulfadiazine allergy.

Mafenide (Sulfamylon) is another commonly used antimicrobial agent. Mafenide is available as a cream and, more recently, as a 5% solution. Mafenide, like silver sulfadiazine, has a broad antimicrobial spectrum, including gram-positive and gram-negative organisms. In addition, mafenide readily penetrates burn eschar, making it an excellent agent for treating burn wound infections. Mafenide is commonly used on the ears and the nose because of its ability to protect against suppurative chondritis; however, silver sulfadiazine appears to be equally effective in this setting. Since mafenide penetrates eschar well, twice-daily administration is typically necessary. Mafenide-soaked gauze can also be used as a dressing for skin grafts that have been placed over an infected or heavily colonized wound bed. There are two well-recognized drawbacks of mafenide. Mafenide is a potent carbonic anhydrase inhibitor and, therefore, can cause a metabolic acidosis. This problem can confound ventilator management. In addition, the application of mafenide can be painful and therefore its use may be limited in partial thickness burn wounds.

Silver nitrate is another commonly used topical antimicrobial agent. Silver nitrate provides broad-spectrum coverage against gram-positive and gram-negative organisms. It is relatively painless on administration and needs to be applied every 4 hours to keep the dressings moist. Silver nitrate has two principal drawbacks. First, it stains everything it touches black, including linen, floors, walls, and staff’s clothing. Second, since silver nitrate is prepared in water at a relatively hypotonic solution (0.5%), osmolar dilution can occur resulting in hyponatremia and hypochloremia. Therefore, frequent electrolyte monitoring is needed. Rarely, silver nitrate can cause methemoglobinemia. If this occurs silver nitrate should be discontinued.

Bacitracin, neomycin, and polymyxin B ointments are all commonly used for coverage of superficial wounds either alone or with petrolatum gauze to accelerate epithelialization. These ointments are also used routinely in the care of superficial face burns. Mupirocin (Bactroban) is another topical agent that is effective in treating methicillin-resistant Staphylococcus aureus (MRSA). Mupirocin should be used only when there is a culture-proven MRSA infection to avoid the development of resistant infections.

Fluid Resuscitation

Significant burn injury not only results in local tissue injury but also initiates a systemic response that impacts nearly every organ system. The release of inflammatory mediators (including histamine, prostaglandins, and cytokines) can lead to decreased cardiac output, increased vascular permeability, and alteration of cell membrane potential. The purpose of fluid resuscitation is to provide adequate replacement for fluid lost through the skin and fluid lost into the interstitium from the systemic capillary leak that occurs as part of the body’s inflammatory response. Therefore, significant volumes of intravenous fluid may be required to maintain adequate organ perfusion.

An understanding of burn shock physiology is essential to understanding the rationale for the various formulas that have been described for fluid resuscitation. Burn injury destroys the body’s barrier to evaporative fluid losses and leads to increased cellular permeability in the area of the burn. In addition, in cases of larger burns (>20%), there is systemic response to injury that leads to capillary leakage throughout the body. Arturson2 in 1979 demonstrated that increased capillary permeability occurs both locally and systemically in burns greater than 25%, and Demling3 demonstrated that half of the fluid administered following 50% TBSA burns ends up in uninjured tissue. Therefore, burn resuscitation must account not only for the loss of fluid at the site of injury but also to the leak of fluid throughout the body. These losses are even greater if an inhalation injury is present since there will be increased fluid leak into the lungs as well as an increased release of systemic inflammatory mediators. Capillary leak usually persists through the first 8 to 12 hours following injury.

The use of formal fluid resuscitation is reserved for patients with burns involving more than 15% to 20%. Awake and alert patients with burns less than 20% should be allowed to resuscitate themselves orally as best as possible. A number of approaches using a number of different solutions have been proposed for intravenous fluid resuscitation.

Crystalloid. The Parkland formula, as described by Baxter, is still the most commonly used method for estimation of fluid requirements (Table 15.4]). The formula (4 cc × weight in kilograms × %TBSA) provides an estimate of fluid required for 24 hours. The fluid administered should be Lactated Ringer’s (LR). LR is relatively hypotonic and contains sodium, potassium, calcium, chloride, and lactate. Sodium chloride is not used because of the risk of inducing a hyperchloremic acidosis. Half the calculated fluid resuscitation should be administered over the first 8 hours and the second half administered over the next 16 hours. Children who weigh less than 15 kg should also receive a maintenance IV rate with dextrose-containing solution since young children do not have adequate glycogen stores.

It is important to remember that the formula provides merely an estimate of fluid requirements. Fluid should be titrated to achieve a urine output of 30 cc/h in adults and 1 cc/kg/h in children. Therefore, a Foley catheter should be used to accurately track urine output. If urine output is inadequate, the fluid rate should be increased; conversely, if the urine output is greater than 30 cc/h, the fluid rate should be decreased. Fluid boluses should only be used to treat hypotension and should not be used to improve urine output. Patients with deeper, full thickness burns and patients with inhalation injury tend to require higher volumes of resuscitation.

Colloid. Protein solutions have long been used in burn resuscitation and have been the subject of debate for decades. The use of colloid has the advantage of increasing intravascular oncotic pressure, which could theoretically minimize capillary leak and potentially draw fluid back intravascularly from the interstitial space. The Brooke and Evans formulas developed during the 1950s and 1960s both included the use of colloid in the first hours of resuscitation. However, the use of colloid in the early postburn period can lead to the leakage of colloid into the interstitial space, which can aggravate tissue edema. Therefore, colloid is typically not used until 12 to 24 hours following burn injury when the capillary leak has started to seal.

Several different colloid formulations have been used. Albumin is the most oncotically active solution and does not carry a risk of disease transmission. Fresh frozen plasma has also been used, but since this is a blood product, there is a risk, albeit small, of disease transmission. Dextran is a nonprotein colloid that has also been used in burn resuscitation. Dextran is available in both a low and high molecular weight form. Low molecular weight dextran (dextran 40) is more commonly used. Dextran increases urine output with its osmotic effect, and therefore, urine output may not be an accurate indicator of volume status. In addition, dextran has the disadvantage of relatively and potentially catastrophic allergic reactions.

Hypertonic Saline. Hypertonic saline solutions have been used for many years for burn resuscitation. Advocates of hypertonic saline argue that hypertonic solutions increase serum osmolarity and minimize the shift of water into the interstitial space. This should theoretically maintain intravascular volume and minimize edema. However, this theory has not been well substantiated in the literature.4

Regardless of the type of resuscitation fluid used, urine output is the best indicator of resuscitation. Tachycardia is often present as a result of the body’s systemic inflammatory response, pain, or agitation and, therefore, is not as accurate a barometer of volume status. The use of pulmonary artery catheter parameters to guide fluid resuscitation has been found to lead to overresuscitation. Serial lactate and hematocrit measurements serve as secondary indicators of resuscitation. Poor urine output is likely the result of hypovolemia and is therefore appropriately treated with increased fluid administration, not diuretics or pressors.

The risks of underresuscitation are well understood: hypovolemia and worsening organ dysfunction. More recently, the risks of overresuscitation are becoming clear as well. The need for intubation, prolonged ventilation, and increased extremity edema that can extend the zone of burn injury and the potential for extremity and abdominal compartment syndrome can all result from excessive fluid resuscitation.5,6

While there are several formulas to guide fluid resuscitation in the first 24 hours following burn injury, it is important to remember that patients may continue to have large fluid requirements for several days following injury. At the conclusion of the first 24 hours, fluids should not be discontinued, but rather titrated for a goal urine output of 30 cc/h. Patients with large burns will have large volumes of insensible losses that will require replacement with intravenous fluids.

Decision Not to Resuscitate

Despite the significant advances in burn care, some injuries are not survivable. In cases of extensive burn injury, a decision is made regarding the potential futility of resuscitation and subsequent surgical management. This is clearly a difficult decision that needs to be based on several factors: an accurate assessment of the patient’s injury, location of burns, depth of burns, presence of inhalation injury, the patient’s age and comorbidities, and the typical mortality level based on these factors.

There have been several formulas described for estimating mortality, but none is perfect. Baux suggested that adding age and TBSA gives an estimate of mortality. Zawacki’s description of the Z score is another formula that has been described to estimate mortality. The score is based on several factors including extent of burn injury, extent of full thickness burn injury, presence of inhalation, and age.7

Part of the difficulty in determining survivability is that each burn is quite different. In addition, each patient is quite different. This is particularly true in older patients, since there is great heterogeneity in patients of the same age. Prior to making a decision regarding resuscitation, frank discussion with the patient’s family, if possible, should occur. Members of the burn team—particularly the nurses caring for the patient—should be included in the discussion and comfortable with the very difficult decision to not resuscitate.

Patients who are awake and alert who are not candidates for resuscitation should also be involved in the process. These patients should be informed of the decision not to resuscitate and given the opportunity to talk with family members. Often patients with extensive full thickness burns can be extubated and be awake and alert enough to have an opportunity to say good-bye to family members.

INHALATION INJURY

The inhalation of the products of combustion can lead to devastating pulmonary injury. Direct thermal injury occurs rarely and usually only in the case of steam burns. Inhalation injury significantly increases burn mortality for a given percent skin burn. Carbon monoxide inhalation is potentially devastating since carbon monoxide will bind to hemoglobin and interfere with the delivery of oxygen.

Diagnosis of inhalation injury is best made by consideration of the circumstances surrounding the burn injury and findings on physical examination. However, the gold standard for diagnosis is bronchoscopy. Evaluation of inhalation injury should include an arterial blood gas and carboxyhemoglobin level. An elevated carboxyhemoglobin is consistent with inhalation injury; however, patients who smoke will have an elevated baseline carboxyhemoglobin, sometimes as high as 10. In addition, the carboxyhemoglobin level should be interpreted in light of the time since injury and the level of oxygen support the patient has received since the injury. The half-life of carboxyhemoglobin on 100% oxygen is 40 minutes, so a patient with a carboxyhemoglobin level of 10 forty minutes following injury may have had an initial level of 20.

Management of inhalation injury is usually supportive. Patients with signs and symptoms of inhalation injury may require intubation. In general, it is better to secure a patient’s airway early in the postburn period, particularly if the patient is going to require large volumes of fluid resuscitation. In addition, if a patient with a suspected inhalation injury has a worsening respiratory status, intubation should be promptly performed. Aggressive pulmonary toilet, bronchodilators, and clearing of secretions are all essential components of patient management. Steroids have not been shown to be beneficial in the treatment of inhalation injury, and the use of prophylactic antibiotics should be avoided. Radiographs may be useful following admission to evaluate possible pneumonia. Repeat bronchoscopy can be useful in obtaining sputum samples for culture and for assistance in suctioning sloughed mucosa that the patient is unable to clear. Patents who sustain inhalation injury are at increased risk for respiratory failure and subsequent infection.

Patients who develop signs of adult respiratory distress syndrome should be placed on low (protective) tidal volumes on the ventilator in order to protect the pulmonary parenchyma from additional damage. Typically, these lower tidal volumes will result in hypercapnia, which should be permitted in order to protect the lungs.

The utility of hyperbaric oxygen for patients with elevated carboxyhemoglobin levels has long been debated. The potential benefit of hyperbaric oxygen is the rapid reduction of carbon monoxide levels, with the potential to minimize potential neurologic sequelae of carbon monoxide poisoning. Hyperbaric oxygen can reduce the half-life of carbon oxide from 40 minutes on 100% FiO2 to 20 minutes. However, hyperbaric oxygen is not without risk. Hyperbaric oxygen can cause pneumothorax and perforation of the tympanic membranes. If the patient must be transported to another medical center for hyperbaric oxygen, it may be possible to effectively treat an elevated carboxyhemoglobin with 100% oxygen in the time it takes to transport the patient to the hyperbaric chamber. One must also carefully weigh the risks of placing a critically ill patient in a chamber where access might be limited. Any patient who is hemodynamically unstable, requires aggressive resuscitation, and is hypothermic should probably not be transported for hyperbaric oxygen.

Nutrition

Nutritional support is a cornerstone of burn patient management. Hypermetabolism and hypercatabolism both occur following burn injury. This increased metabolic rate begins immediately following injury and persists until complete wound coverage is achieved. In addition, the nutritional requirements to heal burn wounds, skin grafts, and donor sites all increase the nutritional needs of the burn patient.

Feedings, whether oral or enteral, should be initiated as soon following admission as possible. Most patients with burns of under 20% TBSA can obtain enough calories on their own. However, patients with larger burns or patients who will be intubated for several days should have an enteral feeding tube placed on admission. Ileus following burn injury commonly occurs, and it may take days for the return of gastrointestinal function. However, ileus can be prevented by starting feeds in the immediate post-injury period. The burn team’s dietician should be consulted to assist in determining nutritional needs, to provide monitoring of caloric intake, and to make appropriate adjustments to the patient’s nutrition plan. Due to the high levels of narcotics patients receive, routine use of stool softeners should also begin on admission to prevent constipation and intolerance of feedings.

Parenteral nutrition is associated with higher rates of infection, attributable, in part, to the prolonged need for central venous access. Parenteral nutrition should only be used in cases when the patient has a prolonged paralytic ileus, pancreatitis, bowel obstruction, or other contraindication to enteral feeding.

There are several equations for the estimation of caloric requirements. The two most commonly used formulas for calculating caloric requirements are the Curreri formula and the Harris-Benedict formula. The Curreri formula differs for children and adults:

Adults: 25 kcal × weight (kg) + 40 kcal × %TBSA

Children: 60 kcal × weight (kg) + 35 kcal × % TBSA

The Harris-Benedict formula provides an estimate of basal energy expenditure (BEE):

Men: 66.5 + 13.8 × wt (kg) + 5 × height (cm) - 6.76 × age (years)

Women: 655 + 9.6 × wt (kg) + 1.85 × height (cm) - 4.68 age (years)8

The calculated BEE is multiplied by an injury factor (typically 2.1 for patients with large burns) in order to provide an estimate of caloric requirements. The Curreri formula generally overestimates caloric requirements, particularly in the elderly, and the Harris-Benedict formula can underestimate caloric requirements, so an average of the two is often used. Indirect calorimetry using a metabolic cart can be used for patients on a ventilator. However, the formula is less reliable at FiO2 levels above 50%. The metabolic cart will provide an estimate of energy expenditure by measuring oxygen consumption and carbon dioxide production. In addition, a respiratory quotient can be calculated from these data, which will provide information about whether the patient is being overfed or underfed.

Protein requirements should also be calculated. Burn patients catabolize significant amounts of skeletal muscle and require protein replacement not only to maintain muscle mass and function but also to provide building blocks for wound healing. Patients with normal renal function should receive 2 g of protein per kilogram per day. Supplemental vitamins and minerals should also be provided to optimize wound healing. Vitamins A and C, as well as zinc have known benefits in wound healing and the use of vitamin E, selenium, and iron supplements has also been described.

Regular nutrition monitoring, particularly for intensive care unit patients, should be performed. Our practice is to obtain weekly C-reactive protein, albumin, prealbumin, and vitamin C levels as well as a 24-hour total urea nitrogen. Calorie counts should be used to monitor the patient’s oral intake and help determine when enteral feeds can be safely weaned and ultimately discontinued.

Blood glucose levels should be closely monitored on patients, particularly those in the intensive care unit. Enteral feeding, along with the body’s systemic inflammatory response, can increase blood glucose levels. The benefits of tight glucose control in critically ill patients have been well documented. Sliding scale insulin coverage should be initiated on all patients in the intensive care unit and there should be a low threshold for initiating an insulin drip, since this will allow for tighter blood sugar control.

Gastrointestinal Prophylaxis

Stress ulcers (Curling’s ulcers) were once a common complication following severe burn injury. The development of prophylactic agents, including histamine receptor blockers, sucralfate, and protein pump inhibitors, has nearly eliminated the occurrence of stress ulcers. Perhaps the best protection against stress ulcers is feeding the patient. Feeding the stomach early in the hospital course will minimize posttraumatic gastric atony, will provide continuous coating of the stomach, and is easier to place at the bedside than a duodenal tube. Stress ulcer prophylaxis is therefore only necessary in those patients who are not taking oral or enteral feeds or those with a previous history of peptic ulcer disease.

Deep Venous Thrombosis

Patients who sustain burn injuries often have multiple risk factors for deep venous thrombosis. Injuries to the extremity as well as the occasional need for prolonged bed rest (particularly in the intubated patient) and indwelling catheters increase the risk of venous thrombosis. Therefore, deep venous thrombosis prophylaxis is required in burn patients who are hospitalized and are unable to regularly ambulate.

Infection

Infection remains a significant risk following burn injury. Prolonged intensive care unit stay, prolonged periods of intubation and mechanical ventilation, and potential colonization of burn eschar contribute to the risk of infection. In addition, indwelling vascular and bladder catheters provide another source of invasive infection. In fact, nearly all patients with major burns have bouts of infection.

Burn patients are also functionally immunocompromised for a number of reasons. First, the skin that serves as the principal barrier between an individual and the environment is lost. Similarly, the mucosal barrier of the respiratory tract may also be injured. In addition, the cellular and humoral portions of the immune response are compromised following burn injury. Decreased production of antibodies and impaired chemotaxis and phogocytosis all increase the risk of infection and decrease the body’s ability to fight infection.

The diagnosis and management of infection in the burn patient can be challenging. Fevers and leukocytosis can result from the systemic inflammatory response to burn injury and not necessarily infection. Thrombocytosis is also frequently observed in stable burn patients. Nearly all patients with greater than 15% TBSA burns will be febrile within the first 72 hours following burn injury. Therefore, routine culture of these patients in this early time period is likely unnecessary. However, following the initial 72 to 96 hours, periodic cultures are important in making a diagnosis of infection. Temperature spikes warrant culturing of urine, sputum, blood, and central lines. In addition, any change in the patient’s status including hypotension, altered mental status, intolerance of tube feeds, hyperglycemia, and hypoglycemia should raise the suspicion of infection.

Management of infections in burn patients must be culture driven. Presumptive broad-spectrum antimicrobial coverage is fraught with potential complications including breeding resistant organisms and increasing the risk of fungal infections. Selection of antibiotics should be based on culture results. In the case of suspected pneumonia, bronchoscopic samples may be helpful in differentiating pneumonia from airway colonization.

Pain Control

Pain management is an important factor in caring for the burn patient. Burn patients typically have two types of pain: background and procedural. Background pain is present on a daily basis with little variation. Procedural pain occurs during daily wound care and therapy. The best approach to pain management is to keep it simple. Polypharmacy can easily occur on a patient who is hospitalized for a long time and will make weaning the patient from the medications very difficult.

Background pain is best treated with longer acting agents. Methadone can be used for patients who are going to have a long hospital course. Methadone has a half-life of 6 hours and can reduce the need for high doses of other agents. However, patients on methadone require a taper prior to discontinuation of the medication. Oxycodone or morphine can then be used for breakthrough pain. Nonsteroidal agents should be avoided in patients likely to undergo surgical excision and grafting. For procedural pain, shorter acting agents are probably best since wound care is usually a short-duration activity. Many patients—particularly children—may also benefit from low-dose benzodiazepines since wound care can be anxiety provoking for many patients. Again, the use of short-acting benzodiazepines is favorable.

SURGICAL MANAGEMENT

Early burn excision and skin grafting has become the standard of care for full thickness burn wounds. The concept of early excision was popularized in the early 1970s by Janezovic.9 Traditionally, burn eschar was left on the wound and proteolytic enzymes produced by neutrophils and bacteria would lead to the separation and sloughing of the eschar. The underlying granulating wound would then be skin grafted. It has become clear, however, that in cases of extensive burn injury, this delay in management results in more extensive bacterial colonization and increased likelihood of burn wound sepsis, multiple organ failure, and, ultimately, death.

The benefits of early burn excision are clear and have been well documented.9-12 Early excision and grafting results in increased survival, decreased infection rates, and decreased length of hospital stay. In addition, early removal of burn eschar also appears to decrease the risk of hypertrophic scarring.

If feasible, early staged excision should begin on postburn day 3 for major burns that are clearly full thickness. Operations can be spaced 2 to 3 days apart until all eschar is removed and the burn wound covered. The interval days are to allow for stabilization and resuscitation of the patient. Excised wounds can be temporarily covered with biologic dressings or cadaveric allograft until autogenous donor sites are available.

Techniques of Excision

There are two techniques of burn wound excision: tangential excision and fascial excision. Tangential excision is the sequential removal of layers of eschar and necrotic tissue until a layer of viable, bleeding tissue that can support a skin graft is reached. Tangential excision is carried out using Watson or Goulian (Weck) blades (Figure 15.6). The Watson blade has a dial to set the depth of excision and the Goulian blades come with guards of varying opening to allow adjustment of excision depth. These settings and guards are only guides, and ultimate depth of excision is influenced by the operator. There are two principal disadvantages of tangential excision. First, when excising a large surface area, there can be substantial blood loss and, second, it may be difficult to accurately assess the viability of the excised wound bed. This can particularly be a problem when excision is carried down to fat.

FIGURE 15.6. Tangential excision is performed using a Watson (shown above) or Goulian knife. Tissue is serially excised until viable, bleeding tissue that can accept a graft is reached.

Fascial excision involves excision of the burned tissue and subcutaneous tissue down to the layer of the muscle fascia. Fascial excision can be carried out using electrocautery, which makes for a more hemostatic excision (Figure 15.7). In addition, by carrying out excision through a well-defined anatomic plane, it is easier to control bleeding by identifying and ligating larger vessels. However, in performing fascial excision, it is possible that viable subcutaneous tissue is being excised. Fascial excision can also result in a cosmetically unacceptable contour deformity and lymphedema of the excised extremities.

A newer device for burn excision is the water jet–powered VersaJet (Hydrosurgery System; HydroCision, Andover, MA). This device provides a relatively facile and precise tool for the excision of eschar and is particularly useful for excision of concave surfaces of the hand and feet as well as for excision of the eyelids, ear, and nose (Figure 15.8).13

Regardless of which technique is used, extremity excisions should be performed under tourniquet control to minimize blood loss. In addition, suspension of the upper and lower extremity from overhead hooks can facilitate excision and graft placement, particularly on the posterior aspect of the lower extremities. The risks of blood loss and probable need for transfusion should be clearly communicated to the anesthesia team prior to the start of excision. In addition, the operating room should be warmed and bear huggers should be used when possible to minimize hypothermia.

Adequate hemostasis is critical to minimizing hematoma formation and ultimately graft loss. Telfa pads (Kendall, Mansfield, MA) soaked in an epinephrine solution (1:10,000) are a mainstay of hemostasis, combined with topical pressure and cauterization when necessary. More recently, the use of fibrin glue has gained popularity in assisting with hemostasis as well as with graft fixation.

Skin Grafting

The process of engraftment is essentially that of revascularization of the graft. Initially, the graft has no vascular connection with the recipient bed and survives through the process of diffusion of nutrients from the wound bed, a process known as plasma imbibition. Typically, the process of revascularization will begin 48 hours after graft placement. The process of revascularization occurs by a combination of neovascularization (ingrowth of host vessels into the graft) and inosculation, the direct biologic anastomosis of cut ends of recipient vessels in the graft bed with those of the graft itself. Concomitant with revascularization of the graft is the organization phase, which describes the process by which the graft integrates with the wound bed.

FIGURE 15.7. This elderly patient had full thickness burns to the chest that were excised using a fascial excision. The edges of the wound were sutured to the pectoral fascia to minimize the ledge at the perimeter of the excision.

FIGURE 15.8. The VersaJet water dissector is a new technology that can be very useful for the excision of the eyelids (shown above), ears, and web spaces.

Skin grafts are typically classified according to their thickness as either split (partial) thickness or full thickness depending on whether they include the full thickness of the dermis or just a portion of it. Split thickness grafts are further classified into thin, intermediate, or thick depending on the amount of dermis. The thinner a skin graft, the more contraction that occurs at the recipient site following transplantation. Thicker grafts contract less at the recipient site, but leave a greater dermal deficit at the donor site, which will therefore take longer to heal and have an increased risk of hypertrophy.

Skin grafts can also be meshed or unmeshed (sheet grafts). From an aesthetic standpoint, sheet grafts will always be superior to meshed grafts. It is best to perform sheet grafting over the face, hands, and forearms since these are exposed areas. In larger burns, there is inadequate skin available to perform sheet grafting over all burned areas and the skin grafts need to be meshed. Skin grafts can be meshed 1:1, 2:1, 3:1, 4:1, and even 6:1. However, for practical and cosmetic purposes, mesh of 2:1 is the most commonly used. Meshing of skin grafts allows for the egress of fluid from the wound bed, which minimizes seroma and hematoma formation and therefore decreases the risk of graft loss. In addition, meshing a graft allows for expansion, which provides greater wound coverage.

Skin grafts can be affixed to the wound bed using a variety of techniques. Staples are the most commonly used and are probably the most expeditious way to secure grafts when a large area of the body is being covered. Suturing of grafts is particularly useful in children because absorbable sutures need not be removed. We have had a great deal of success using Hypafix (Smith and Nephew, London, England), particularly for fixation of sheet grafts. Hypafix is an elastic adhesive dressing that can be easily applied using mastisol as an adhesive. The Hypafix remains in place and can only be removed by using Medisol. Fibrin glue and other tissue sealants have also been used to affix skin grafts to the wound bed.

There are numerous options for skin graft dressings. Typically, the decision is guided again on the type of graft—meshed or unmeshed—and on the location of the graft.

A number of dressings can be used for meshed skin grafts. Wet dressings, consisting of antimicrobial solution (Sulfamylon), provide a moist environment to accelerate epithelialization of the interstices. Greasy gauze and Acticoat (Smith and Nephew) have also been used as dressings over meshed grafts. Acticoat is a relatively new antimicrobial dressing that consists of a polyethylene mesh impregnated with elemental silver. Silver provides antimicrobial activity by disrupting bacterial cellular respiration. Both greasy gauze and Acticoat are capable of providing a moist environment that will accelerate closure of graft interstices. Bolsters of cotton or greasy gauze are needed when grafts are placed over areas of convexity or concavity.

Sheet grafts can be left open to the air to allow for monitoring or can be dressed with a nonadherent gauze. Typically, dressings over sheet grafts are removed on the day following skin grafting to allow for evacuation of seroma or hematoma that can occur. Facial skin grafts should similarly be covered with a nonadherent or greasy gauze and we will commonly use a Jobst skin featureless facemask garment (Beiersdorf-Jobst, Inc., Rutherford College, NC) to minimize graft sheering.

The Vacuum Assisted Closure (VAC; Kinetic Concepts Inc., San Antonio, TX) device is another option for skin graft coverage. The VAC is a negative pressure device that is able to prevent graft sheering and is particularly useful over areas of convexity or concavity. The VAC can be left in place over a skin graft for 5 days and then can be easily removed at the bedside. Alternatively, an Unna boot can be applied over grafts of the arm and leg. The Unna boot will provide vascular support and prevent graft sheering while allowing early mobilization.

Donor Site Selection and Care

Selection of donor sites is often dependent on the availability of unburned skin. For children, the buttock and scalp provide the most inconspicuous donor sites. Plasmalyte can be infused subcutaneously to facilitate graft harvest in these areas. When larger amounts of skin are needed, then the thighs and back can be used.

The ideal donor site dressing would minimize pain and infection, accelerate epithelialization, and be cost-effective. There are a number of donor site dressings available, which may suggest that no perfect dressing exists.

Management of Specific Areas

Face. Plastic surgeons who do not routinely care for burn patients may be called upon to manage facial burns—both acute and reconstructive. Few areas of burn care can be more challenging than the management of facial burns. The aesthetic and functional outcomes are critical to the daily life of the patient and intimately related to feelings of self-esteem.

Management of facial burns begins at the time of admission. Many patients with facial burns sustain inhalation injuries and are intubated. The endotracheal tube should be secured in such a way so as to minimize pressure necrosis of the lip. Patients who are going to be intubated for a long period of time may benefit from the wiring of the endotracheal tube to the teeth or to a segment of an arch bar that can be wired to the upper teeth. This provides a reliable and sturdy method for tube fixation and will minimize pressure on the lip. This will also allow for facile and secure positioning of the tube in the operating room (Figure 15.9). In addition, consideration for tracheostomy should be made if a prolonged period of intubation is required. While the benefits of early tracheostomy are not well established in burn patients, tracheostomy will allow improved pulmonary toilet to reduce pneumonia risk. If the neck is burned as well as the face, the neck can be excised and tracheostomy performed in the same setting. If a feeding tube is placed, care must be taken to minimize alar or columellar pressure necrosis.

FIGURE 15.9. The endotracheal tube can be secured to a segment of an arch bar and then suspended from the ceiling using a rope. This provides both stable fixation of the tube and complete access to the face for excision.

All patients with periorbital burns should undergo an intraocular exam with a Wood’s lamp. If this exam is positive, then an ophthalmologic consult is required. In addition, if the patient has lagophthalmos, it is important to keep the eyes well moisturized with ophthalmic ointment to prevent exposure keratitis. Despite optimal periorbital burn and ocular management, patients may still develop conjunctivitis and/or exposure keratitis. In these cases, consideration for reversible lateral marginal tarsorrhaphy should be made.14-18

The practice of excising facial burns has long been debated in the literature.15-18 The traditional method of facial burn management was to perform daily wound care until the face either healed or the underlying eschar lifted, leaving a granulating wound bed that could accept a skin graft. It is now clear that better outcomes are achieved if non-healing areas are excised and then subsequently skin grafted. As in other parts of the body, it is generally easy to determine the healing capacity of shallow burns and deep burns. The burns of indeterminate depth pose a greater challenge.

Over the past 30 years, it has been our practice at the University of Washington to excise facial burns. Our protocol and results can be found in recent publications.19,20 Patients who are admitted with facial burns undergo debridement of loose blisters and debris and then daily wound care. It has become our practice to assess patients with facial burns at day 10, at which time it is usually clear which burns will heal within 3 weeks and which will not. Patients with burns that are thought to not be able to heal within 3 weeks are scheduled for excision and grafting. It is important to note that patients with full thickness burns with clearly no healing potential should be operated on in the first week to 10 days if the patient is stable and there are no other more urgent areas of excision.

Facial excision is typically carried out using Goulian blades. Traction sutures are frequently used on the upper and lower eyelids to aid in excision. More recently, the availability of the VersaJet water dissector has helped in excising areas with difficult contour such as the eyelids and ears. Small areas of exposed cartilage of the ear should be excised and the skin closed primarily over the defect.

Sheet autograft is always used for coverage of the face. The appearance of meshed grafts to the face is cosmetically unacceptable. The scalp is an excellent source of autograft, given the color match with the face. However, in the case of full facial burns, scalp skin is usually inadequate and a different donor site is needed so there is uniformity in the coloring of the skin grafts. A facemask (such as a Jobst skin featureless facemask) should be placed in the operating room to help immobilize the skin grafts. Skin grafts should be inspected on the first postoperative day so any blebs or fluid collections that may impair graft take can be drained.

Neck. Excision and grafting of the neck can also be challenging. The key to management of the neck is to make every effort to minimize wound and graft contraction. Whenever possible, it is best to cover the neck with sheet grafts. The grafts should be placed with the neck in maximal hyperextension. For the first several days following graft placement, the neck should be immobilized in a splint. Once the grafts have taken, the patient should be started on aggressive range of motion exercises. Aggressive range of motion exercises are critical both for patients who heal without grafting and for patients who undergo grafting. These exercises should continue for the several months it takes for the grafts to mature.

Hands. Hand burns occur from a variety of mechanisms. In the pediatric population, hand burns frequently occur as a result of contact with a fireplace or wood stove or from grabbing a hot object. The palm has excellent healing capacity and these pediatric palm burns rarely require grafting. However, it is critical to emphasize to the patient’s parents the importance of range of motion exercises. Stretching should be performed on a routine basis—either during diaper changes or feeding times—to minimize contractures of the palm and digits. In the cases of deeper palm burns, nocturnal extension splints may be necessary. It is also important to emphasize to parents to let the child use his or her hands as soon following injury as possible and bulky dressings that inhibit mobility should be minimized.

Similarly, adult hand burns often heal without the need for skin grafting. Patients are encouraged to begin range of motion exercises as soon following burn injury as possible. Range of motion exercises will reduce extremity edema and also optimize the return of function once the skin wounds have healed. Static splinting is not recommended, unless the patient is intubated and unable to participate in therapy. If splinting is necessary, the wrist should be placed in mild extension, the metacarpophalangeal joints in 70° to 90° of flexion, and the interphalangeal joints in extension. Even in those instances, however, therapists should regularly range the extremities.

If it is clear that a burn wound will not be healed within 3 weeks, is best treated by excision and grafting. With few exceptions, burns of the hand should be grafted with sheet grafts. Hand excision, particularly of the web spaces and digits, can be challenging. Great care should be taken to not expose tendons. In addition, excision should occur under tourniquet control. If a burn is so deep that adequate excision would surely expose tendons, then flap coverage should be considered.

Following excision and grafting of the hand, splint immobilization should occur for at least 5 days postoperatively. The wrist should be positioned in slight extension, the metacarpophalangeal joints should be placed in flexion, the interphalangeal joints in extension, and the thumb in abduction. Graft take should be assessed at postoperative day 5 and the decision for initiation of range of motion exercises should be made. Once graft healing is complete, compression gloves that will minimize hand edema and possibly scar hypertrophy should be worn.

Perineum. Scald burns remain the most common burns of the perineum and they typically result from the spilling of hot beverages that are held between the legs while driving. These scald burns tend to heal within 1 to 2 weeks time, and wound care and pain control are the mainstay of treatment. Full thickness burns can occur as part of a larger flame burn and the healing potential of these injuries can be more varied. It is not necessary to insert a Foley in all patients who sustain perineal burns. In fact, all patients should be given the option to void spontaneously and a catheter should be placed only if they have difficulty voiding. An external genital burn is not likely to lead to urethral (internal) stenosis. Deep burns to the penis and scrotum should be given ample time to heal. In fact, the scrotum is rarely grafted since it can usually heal by contraction and not leave a noticeable scar. Patients who sustain full thickness, charred burns of the genitals and cannot have a Foley placed should be evaluated by the urologists for placement of a suprapubic tube.

Lower Extremities. Of all the burns treated in the outpatient setting, patients with feet and leg burns tend to have the most difficulty. Edema can delay wound healing and increase patient discomfort. The key to treating lower extremity burn wounds is to encourage the patient to ambulate, with the appropriate support of an ace bandage or Tubigrip (ConvaTec, Princeton, NJ). Ambulating minimizes the pooling of blood in the distal aspect of the extremity and thereby decreases edema. In addition, the sooner the patient is able to ambulate, the sooner they will be able to resume normal level of activities once their wounds heal. While not ambulating, leg elevation can be helpful in minimizing edema as well.

If leg or foot burns require excision and grafting, consideration needs to be made of the postoperative physical therapy plan. Small burns of the leg and foot can be grafted and dressed with greasy gauze and then covered with an Unna boot. The Unna boot provides support and immobilization of the graft and allows for early mobilization. This is an excellent dressing for both adults and children. Patients with insensate feet are poor candidates for Unna boot dressings. Patients who require grafting both above and below the knee should be fitted with knee immobilizers postoperatively to maintain knee extension.

Outpatient Burn Management

Most burn patients will have some aspect of their care in the outpatient burn clinic. Again, a multidisciplinary approach in this setting is crucial to the success of outpatient burn wound management. Experienced nurses, physical and occupational therapists, and psychologists all play an important role in patient management, even in the outpatient setting. Issues of range of motion, optimization of function, and the psychosocial aspects of reintegration into society all must be dealt with in the outpatient clinic. In addition, addressing work-related issues including determining appropriate time to return to work and the potential needs for work accommodations also needs to occur.

There are several other issues particularly relevant to outpatient care. Newly healed burn wounds and donor sites are highly susceptible to blistering and to breakdown. The new epithelium lacks the connections to the underlying wound bed, which will prevent shearing. It often takes up to 6 months to a year for these critical basement membrane structures to reconstitute. Blisters should be decompressed with a sterile pin, the epithelial layer can be left in place, and the area should be covered with a band-aid. Patients should be instructed to soak the band-aid prior to removal to protect against further injury from the adhesive.

CHEMICAL INJURIES

Traditionally, chemical injuries have been classified as either acid burns or alkali (base) burns. The severity of chemical injuries depends on the composition of the agent, concentration of the agent, and duration of contact with the agent. In general, alkaline burns cause more severe injury than acid burns since alkaline agents cause a liquefaction necrosis, which allows the alkali to penetrate deeper, extending the area of injury. Chemical injuries have also been classified according to their mechanism of tissue destruction: reduction, oxidation, corrosive agents, protoplasmic poisons, vesicants, and desiccants.

The first step in managing a chemical injury is removal of the inciting agent. Clothes, including shoes, that have been contaminated are removed. Areas of affected skin are copiously irrigated with water. Adequate irrigation can be verified by checking the skin pH. Burns from chemical powders are the one exception to the rule of water irrigation since the water can activate the chemical. The powder should first be dusted off, and then irrigation can take place. Neutralization of the inciting agent should never be attempted since this will produce an exothermic reaction that will superimpose a thermal injury on top of the chemical injury. Occasionally, the burned individual may not know specifically with which agent they were working and therefore it may be necessary to contact a plant manager or the manufacturer of the suspected inciting agent. If ocular injury has occurred, the eyes should also be copiously irrigated. Eye wash stations should be located in most workplaces where chemicals are used. It is important that the eye be forced open to allow for adequate irrigation. An ophthalmologist should be consulted to assist in the management of these patients.

Certain chemical agents have specific treatments. Hydrofluoric acid (HF) requires specific mention. HF is commonly used in the glass and silicon chip industries as well as in a number of industrial cleaning solutions. HF readily penetrates the skin and continues to injure tissue until it contacts a calcium source, likely bone. Given the ability of the fluoride ion to chelate calcium, patients with even small HF burns are at risk for the development of hypocalcemia, which can be severe enough to have cardiac effects. In fact, HF burns in excess of 10% can be fatal. The use of calcium is the most effective treatment agent. Calcium gluconate gel can be applied topically if the patient is treated rapidly enough, that is, before the HF has penetrated the skin. Direct injection of calcium gluconate into the burned area has long been advocated; however, this may not effectively neutralize the HF and may cause skin necrosis. Therefore, if following copious irrigation and topical treatment with calcium has been ineffective, the patient should be treated with an intra-arterial infusion of calcium gluconate. Diminished pain is the hallmark of effective treatment. Patients with extensive HF burns and certainly patients with intra-arterial infusions require close monitoring and should have frequent serum calcium checks.

Ingestion of chemically toxic agents can occur by children or by adults as part of a suicide gesture or attempt. Again, the principle of lavage to dilute the inciting agent is practiced. These injuries are typically managed by, or in conjunction with, gastroenterologists, pulmonary specialists, or general surgeons. Laryngoscopy and endoscopy should be performed to help define the extent of injury. Enteral feeding beyond the zone of injury is often necessary.

ELECTRICAL INJURIES

Electrical injuries are potentially devastating injuries that result in injury to the skin as well as other tissues including nerve, tendons, and bone. Electrical burns can take several forms including injury from the electrical current itself, flash burns, flame burns, contact burns, or a combination thereof.

Traditionally, electrical injuries have been divided into low voltage (less than 1,000 V) and high voltage (greater than 1,000 V). The considerations and management issues between the two are often different. Following electrical injury, it is important to follow the ATLS protocol and assess the patient’s airway, breathing, and circulation. Once stabilized, it is important to ascertain the circumstances surrounding the injury, the voltage of the injuring current, whether there was loss of consciousness at the scene, other associated injuries (i.e., fall from a cherry picker basket), and whether there was a cardiac or respiratory arrest at the scene.

Evaluation in the emergency room includes a thorough physical examination where the %TBSA is calculated (if there was a flame burn), and the neurovascular status of injured extremities is determined. In addition, all patients who sustain electrical injuries should have an ECG in the emergency room.

Patients with a low-voltage injury who had no loss of consciousness and no dysrhythmia present can be discharged home. The notable exception is a child who has an oral burn from biting an electrical cord. These patients require admission and monitoring for labial artery bleeding.

Management of patients with high-voltage injuries is dictated by the extent of injury, the presence of cutaneous burns, and the presence of myoglobinuria. There is no formula for fluid management of electrical burn patients per se. If there are extensive cutaneous burns, then the Parkland formula is applied and fluid administration is titrated to achieve a urine output of 30 cc/h. If myoglobinuria is present, intravenous fluids should be titrated to a goal urine output of 100 cc/h until the urine clears. Serial urine myoglobin checks are usually unnecessary, since treatment is initiated based on the presence of tea-colored urine and should be continued until the urine clears. If myoglobinuria persists despite fluid resuscitation, then mannitol can be administered. Alkalinization of urine has also been advocated following electrical injury in order to prevent precipitation of myoglobin in the kidney tubules.

Patients who sustain high-voltage injuries should be placed on a cardiac monitor for the first 24 hours following admission. This has been the traditional practice regardless of whether a dysrhythmia is present at the time of admission. There are no data substantiating routine monitoring of high-voltage injuries, and this is a practice that may change over time.

Early management of electrical injuries should focus on the need for fasciotomy or compartment release. Peripheral neurovascular exams are performed to monitor for signs of compartment syndrome. Some patients will present with a contracted upper limb and tight forearm compartments, and these patients undergo immediate fasciotomy and carpal tunnel release (Figure 15.10). Otherwise, progressive sensory and motor loss and increased compartment pressures are indicators of the need for fasciotomy. Many surgeons have argued that all patients should undergo immediate surgery for nerve decompression and debridement of necrotic tissue. On the one hand, carpal tunnel release and fasciotomy are relatively straightforward operations to perform and if the patient derives even a small amount of benefit then the procedures are worthwhile. However, the risks of the procedures, particularly if not necessary, can be significant. Exposure of the median nerve and forearm musculature increases the risk of tissue desiccation and necrosis.

It is often difficult to determine preoperatively who will benefit from the decompression procedures. Decreased sensation and motor function may represent a neuropraxia from direct current injury to the nerve. Mann et al.21 explored the issue of routine immediate decompression of high-voltage injuries. They concluded that a select group of patients require immediate decompression of the arm or hand or both to prevent additive injury from pressure. Clinical indications for this group of patients include progressive motor and sensory exam, severe pain, and loss of arterial Doppler signal and patients who do not adequately resuscitate because of suspected ongoing myonecrosis. Patients with a fixed neurologic deficit typically do not benefit from decompression.

The ideal timing for tissue debridement has similarly been controversial. The ideal time to determine the presence of myonecrosis is typically 3 to 5 days following injury. Therefore, early debridement might not be sufficient since irreversibly injured tissue may not have demarcated. At 3 to 5 days, all unhealthy tissue can be debrided and definitive wound closure can be achieved at this time. In cases of extensive limb injury, free tissue transfer might be necessary to provide wound coverage or to preserve limb length for optimal prosthesis fitting. In these cases, definitive wound closure can be performed at a second operation following wound debridement to allow for appropriate planning and patient counseling.

FIGURE 15.10. This patient sustained a high-voltage electrical injury and presented with a contracted wrist and tight forearm compartment. He was taken emergently to the operating room for forearm fasciotomy and carpal tunnel release.

There are several long-term sequelae of electrical burns of which the patient and physician should be aware. Neurologic deficits including peripheral and central nervous system disorders can develop weeks to months following electrical injury. Therefore, all patients who sustain high-voltage electrical injuries should undergo a thorough neurologic evaluation at the time of admission and prior to hospital discharge. Cataracts can also occur following electrical injury. The exact mechanism is not known, but all patients should undergo a baseline ophthalmologic examination following high-voltage electrical injury. A number of complications can also arise in the injured extremity, including heterotopic ossification (HO), neuromas, phantom limb pain, and stump breakdown if the patient has undergone amputation.

COLD INJURY

Exposure to extremes of cold (and wet) conditions can lead to cellular injury and death. Cell death and tissue necrosis occur from the formation of ice crystals within the cells and extracellular space as well as from microvascular thrombosis. Cellular injury from ice crystal formation occurs during the period of cold exposure, whereas microvascular thrombosis is thought to occur during reperfusion when the affected limb is rewarmed. Similar to burn injury, frost bite injury is classified according to the depth of injury. Mild frost bite, also known as frost nip, is similar to a superficial burn injury, with tissue erythema, pain, and edema. Second-degree frost bite is marked by blistering and partial thickness skin injury. Third-degree frost bite occurs when there is full thickness necrosis of the skin, and fourth-degree frost bite occurs when there is full thickness skin necrosis as well as necrosis of the underlying muscle and/or bone. Again, it is important to note that determination of the full depth of tissue injury is not possible until several weeks following the injury.

The first step in the management of frost bite is removal of all wet clothes, gloves, socks, and shoes. Patients should then be wrapped in warm blankets. Frost bite can also be associated with hypothermia. In these cases, care must be taken to rewarm the entire body. In cases of extreme hypothermia (less than 32°C), warming can be achieved with the use of warm intravenous fluids, bladder irrigation with warm solutions, placement of peritoneal catheters and chest tubes through which warm fluids can be administered, and even, if available, cardiopulmonary bypass. Frost-bitten extremities should be rapidly rewarmed in water that is 40°C. Typically, rewarming can be completed in 20 to 30 minutes. Adjunctive use of nonsteroidal anti-inflammatory medications and calcium channel blockers has also been described.

Patience is required in determining which areas require debridement. There is an old adage that states “frostbite in January, amputate in July.”18 While this might be hyperbole, the concept of allowing tissue to fully demarcate is essential since it is difficult to determine which tissue may survive in the immediate post-injury period. Early debridement and amputation are necessary if soft tissue infection occurs during the waiting period.

Skin Replacement

Early excision and skin grafting has become the standard of care for surgical management of the burn wound. However, in cases of extensive burn wounds, the surface area burned may exceed the available donor sites. In these cases, burn wounds are excised and covered with biologic dressings until complete coverage with autografts can occur. These cases of extensive burn injury have demonstrated the need for a replacement for human skin. Efforts over the past two decades have focused on the development of a temporary and, ideally, permanent replacement to native human skin. While there is no permanent product available to replace both the epidermis and dermis, there have been a number of products introduced over the past decade that address a portion of the skin. Currently, the most commonly used product is Integra (Integra Life Sciences, Plainsboro, NJ). Integra is a bilayer construct; the deeper layer consists of bovine collagen and chondroitin-6-sulfate, and the outer layer is a silastic membrane that serves as a temporary epidermal replacement. Integra is placed on a newly excised wound bed and fixed into place. The silastic layer remains in place until the dermal component vascularizes, which is typically 2 to 3 weeks. Then the patient is taken back to the operating room, the silastic is removed, and a thin (0.006″) autograft is placed on top. The Integra neodermis serves as a scaffold for the ingrowth of tissue from the patient’s wound bed (Figure 15.11). Integra has been used successfully in the management of extensive burns—including burns of the face—as well as for pediatric burns.

LATE EFFECTS OF BURN INJURY

Hypertrophic Scarring

Hypertrophic scarring is one of the most distressing outcomes of burn injury (Chapter 16). Hypertrophic scars can be not only unsightly but painful and pruritic as well. Hypertrophic scarring can occur in grafted wounds and unexcised wounds that took longer than 2 to 3 weeks to heal. Patients with pigmented skin tend to be at a higher risk for the development of hypertrophic scarring. The biologic and molecular basis of hypertrophic scarring is not well understood, and therefore, our ability to prevent hypertrophic scarring is limited (Chapter 2). However, several strategies exist to prevent or minimize hypertrophic scarring. Pressure garments are commonly used over areas that have been grafted or have taken longer than 3 weeks to heal. No study has clearly demonstrated that garments prevent hypertrophic scarring, but the elastic support of the garments can help symptoms of throbbing and pruritis. Silicone has similarly been advocated for the treatment and prevention of hypertrophic scarring. There are several theories as to how and why silicone works, but again, there is no well-accepted explanation. Steroid injection has also been used to minimize the symptoms associated with hypertrophic scarring.

Marjolin’s Ulcer

Marjolin’s ulcer is one of the most dreaded long-term complications of a burn wound. Marjolin’s ulcer is the malignant degeneration of a healed burn wound, which can occur decades following injury. These tumors typically occur in areas that were not skin grafted and are typically aggressive. The presence of an ulceration in a previously healed burn wound should raise the suspicion of malignancy and warrants biopsy and appropriate evaluation.

FIGURE 15.11. The use of Integra for burn wound coverage. A. Full thickness burn wound prior to excision. B. Fascial excision of burn wound leaving a viable, well-vascularized wound bed. C. Application of Integra with silastic left in place. Two weeks later, the silastic was removed and a split thickness skin graft was placed over the Integra.

Heterotopic Ossification

Heterotopic ossification (HO) results from the deposition of calcium in the soft tissue around joints. These calcium deposits block normal joint functioning. HO most commonly affects the elbow and shoulder joints and occurs 1 to 3 months following injury. Patients who develop HO will have increased pain and decreased range of motion of the affected joint. Radiographs demonstrate calcium in the soft tissue. There have been several medical treatments described; however, few have proven to be effective. Surgical management involves direct excision of the heterotopic bone and is usually best carried out once complete wound coverage has been achieved.

Burn Reconstruction

Secondary reconstruction of the burn wound poses one of the greatest challenges to reconstructive surgeons (Chapter 16). The practice of early burn excision has significantly improved outcomes from burn injury. However, the need for reconstruction remains.

While deficiencies in both form and function following burn injury are frequently clear, burn reconstruction poses many hurdles not usually encountered in other areas of reconstructive surgery. There is often an extensive zone of injury with abnormal, scarred tissue that is not amenable to facile rearrangement. In addition, there is usually a combination of problems, including deficiency of tissue, shortened painful scars, and differences in pigment that can be functionally as well as cosmetically debilitating. Furthermore, a patient’s lack of motivation can limit his or her ability to fully participate in the reconstructive plan, especially when it is so difficult to ever achieve what the patient perceives as “normal.”

In general, secondary reconstruction is deferred until graft and scar maturation are complete and the maximal benefits of physical therapy have been realized. It is possible that by the time a scar fully matures, the result may be better than that obtained with a reconstructive procedure. In addition, the time following discharge should be sufficient to allow the patient to begin to reintegrate into society. However, there are exceptions. Eyelid contractures that result in corneal exposure should be corrected early to prevent permanent visual problems. Similarly, scar contractures of the extremities that clearly impede the progress of therapy can be addressed earlier than 1 year in order to maximize the patient’s ultimate gain of function.

An effective reconstructive plan requires the participation of the patient, his or her support system, as well as members of the burn team, including therapists and psychologists. The understanding and agreement to the reconstructive plan in terms of both sequence and timing of procedures is critical to the success of any reconstructive endeavor. The surgeon must always have an understanding of the patient’s priorities, and selection of procedures should, when possible, be consistent with these priorities. In formulating a reconstructive plan, the ability to perform multiple procedures in one setting should also be considered. The reconstructive patient usually wants to minimize the number of operating room trips and hospital stays as these tend to interfere with his or her established daily routine. However, conflicting procedures should not be performed. In addition, donor sites need to be rationed thoughtfully.22

Adequate patient education is of paramount importance. The patient must have a realistic expectation of what can be achieved in reconstruction, including an understanding of limitations. Decisions regarding procedures should be made over a series of detailed discussions, not a single brief clinic visit.22

The first critical step in formulating a surgical plan is the diagnosis of the problem. The determination of tissue deficiency, shortened scar, and contour problems, for example, will help determining which reconstructive procedure is best. Again, it is important to emphasize to the patient that reconstructive surgery can improve the appearance of scars but does not erase all scars. Tissue expanders have been quite useful in various aspects of soft tissue reconstruction including treatment of burn alopecia. Consideration of the patient’s ability to comply with tissue expansion, particularly the need for frequent clinic visits, is essential

CONCLUSION

Despite all the advances in burn care over the past century and the exciting prospects on the horizon, the core of burn care remains the burn team. As each aspect of burn care becomes increasingly complex, with increasingly specialized fields of knowledge, the importance of a team of experts will become even more integral to successful care. Most assuredly, plastic surgeons will always be an integral member of that team.

References

1.  Durtschi M, Orgain C, Counts G, et al. A prospective study of prophylactic penicillin in acutely burned hospitalized patients. J Burn Care Rehabil. 1982;9:606.

2.  Arturson G. Microvascular permeability to macromolecules in thermal injury. Acta Physiol Scand Suppl. 1979;463:111.

3.  Demling R, Mazess R, Witt T, et al. The study of burn wound edema using dichromatic absorptiometry. J Trauma. 1978;18:124.

4.  Gunn M, Hansbrough J, Davis J, et al. Prospective randomized trial of hypertonic sodium lactate versus lactated Ringer’s solution for burn shock resuscitation. J Trauma. 1989;29:1261.

5.  Ivy ME, Atweh NA, Palmer J, et al. Intra-abdominal hypertension and abdominal compartment syndrome in burn patients. J Trauma. 2000;49:387-391.

6.  Klein MB, Hayden D, Elson C, et al. The association between fluid administration and outcome following major burn: a multicenter study. Ann Surg. 2007;245:622-628.

7.  Zawacki BE, Azen SP, Imbus SH, et al. Multifactorial probit analysis of mortality in burned patients. Ann Surg. 1979;189:1-5.

8.  Saffle J, Hildreth M. Metabolic support of the burn patient. In: Herndon DN, ed. Total Burn Care. London: W.B. Saunders; 2002.

9.  Burke JF, Bondoc CC, Quinby WC Jr, Remensnyder JP. Primary surgical management of the deeply burned hand. J Trauma. 1976;16:593-598.

10.  Engrav LH, Heimbach DM, Reus JL, et al. Early excision and grafting vs. nonoperative treatment of burns of indeterminant depth: a randomized prospective study. J Trauma. 1983;23:1001-1004.

11.  Heimbach DM. Early burn excision and grafting. Surg Clin North Am. 1987;67:93-107.

12.  Heimbach DM, Engrav LH. Surgical Management of the Burn Wound. New York, NY: Raven Press; 1985.

13.  Klein MB, Hunter S, Heimbach DM, et al. The Versajet water dissector: a new tool for tangential excision. J Burn Care Rehabil. 2005;26:483-487.

14.  Klein MB, Ahmadi AJ, Sires BS, et al. Reversible marginal tarsorrhaphy: a salvage procedure for periocular burns. Plast Reconstr Surg. 2008;121:1627-1630.

15.  Engrav LH, Heimbach DM, Walkinshaw MD, et al. Excision of burns of the face. Plast Reconstr Surg. 1986;77:744-749.

16.  Fraulin FO, Illmayer SJ, Tredget EE. Assessment of cosmetic and functional results of conservative versus surgical management of facial burns. J Burn Care Rehabil. 1996;17:19-29.

17.  Hunt JL, Purdue GF, Spicer T, et al. Face burn reconstruction—does early excision and autografting improve aesthetic appearance? Burns Incl Therm Inj. 1987;13:39-44.

18.  Jonsson CE. The surgical treatment of acute facial burns. Scand J Plast Reconstr Surg Hand Surg. 1987;21:235-236.

19.  Cole JK, Engrav LH, Heimbach DM, et al. Early excision and grafting of face and neck burns in patients over 20 years. Plast Reconstr Surg. 2002;109:1266-1273.

20.  Klein MB, Moore ML, Costa B, et al. Primer on the management of face burns at the University of Washington. J Burn Care Rehabil. 2005;26:2-6.

21.  Mann R, Gibran N, Engrav L, et al. Is immediate decompression of high voltage electrical injuries to the upper extremity always necessary? J Trauma. 1996;40:584.

22.  Engrav LH. Primary and secondary reconstruction of the burned face. In: Grotting J, ed. Reoperative Aesthetic and Reconstructive Surgery. St. Louis, MO: Quality Medical Publishing; 1995.

Suggested Readings

1.  Luce EA. Burn care and management. Clin Plast Surg. 2000;27:1.

2.  Heimbach DM, Engrav LH. Surgical Management of the Burn Wound. New York, NY: Raven Press; 1984.

3.  Herndon D. Total Burn Care. London: W.B. Saunders; 2002.

4.  Practice guidelines for burn care. J Burn Care Rehabil. 2001.