Abstract
In the past 50 years the incidence of burns has decreased dramatically. Importantly, the survival rates have also improved, leading to more patients needing rehabilitation. This chapter describes the epidemiology, symptoms, and physical examination findings of burn injury. In addition, complications commonly encountered by burn patients are reviewed, including pain, pruritus, hypertrophic scarring, heterotopic ossification, wounds, hypermetabolism, temperature regulation, neuropathy, amputation, and contractures. Current literature regarding these important burn sequelae is discussed and includes up-to-date treatment strategies. Additionally, quality of life, community reintegration, and psychological complications of burn injury are covered in this chapter.
Keywords
burn injury, contractures, hypertrophic scarring, neuropathy, pruritus, work reintegration
| Synonyms | |
| |
| ICD-10 Codes | |
| T20.00XS | Late effect of burn of unspecified degree of head, face, and neck, unspecified site |
| T20.07XS | Late effect of burn of unspecified degree of neck |
| T26.40XS | Late effect of burn of unspecified eye and adnexa, part unspecified |
| T26.41XS | Late effect of burn of right eye and adnexa, part unspecified |
| T26.42XS | Late effect of burn of left eye and adnexa, part unspecified |
| T30.0 | Burn of unspecified body region, unspecified degree (Note: This code is not for inpatient use.) |
| Burns have to be coded by location and then degree (see section T20-T25) | |
| I96 | Gangrene, not elsewhere classified |
Definition
A burn is an injury to the skin or other organic tissue caused by extreme heat, flame, contact with heated objects, or chemicals. There are approximately 486,000 burn injuries requiring medical treatment and 40,000 burn hospitalizations, including 30,000 at burn centers, in the United States each year. Adult burn injury patients are most likely to be young (average age at injury for adults is 42 years) and male (68% to 75%). Most burns in adults result from fire or flame injuries (43% to 61%). Other causes of burns that are also commonly reported include scald, contact, grease, electrical, and chemical injuries. Burns usually happen in the home (73%), but also occur in the workplace (8%) or as a result of motor vehicle accidents (5%). For children, scald injuries are the most common cause and occur more frequently in children younger than 5 years. Additionally, there are disproportionally more scald and inhalation injuries in minority populations. Although there are 3275 estimated deaths from fire and burns annually in the United States, the incidence of burns has decreased dramatically in the past 50 years. In addition, mortality from burn injury has been greatly reduced. A 2014 report demonstrated that half of patients who experience a 90% total body surface area (TBSA) burn survive; in contrast, in the 1940s, only a 20% TBSA burn accounted for a 50% survival rate. These dramatic improvements in survival rates are related to advancements in surgical interventions, systemic antibiotics, critical care support, and the development of comprehensive burn centers ( Table 122.1 ). Survival of patients admitted to burn centers is estimated to be 97%. Once survival is ensured, medical management and treatment of burn injury currently focuses on wound healing, management of complications, and rehabilitation.
| Burn Injuries That Should be Referred to a Burn Center |
| Partial-thickness burns greater than 10% of the total body surface area Burns that involve the face, hands, feet, genitalia, perineum, or major joints Third-degree burns in any age group Electrical burns, including lightning injury Chemical burns Inhalation injury Burn injury in patients with preexisting medical disorders that could complicate management, prolong recovery, or affect mortality Any patient with burns and concomitant trauma (such as fractures) in which the burn injury poses the greatest risk of morbidity or mortality Burned children in hospitals without qualified personnel or equipment for the care of children Burn injury in patients who will require special social, emotional, or rehabilitative intervention |
Symptoms
The symptoms of burn injury are directly related to the depth, size, and location of the injury. As expected, nociceptive pain is a major symptom of burn injury. Involvement of nerve endings in the dermal layer may also result in impaired or altered sensations causing neuropathic pain. Burn pain varies greatly from patient to patient, shows substantial fluctuation over time, and can be unpredictable because of the complex interaction of physiologic, psychosocial, and premorbid behavior issues.
Pruritus is common in the acute period and is linked to both the chronic inflammatory state and altered pain pathways of burns. It has been reported that prevalence rates of post-burn pruritus in adults can be as high as 93%, with the most severe symptoms reported in the first months after wound closure. Risk factors associated with pruritis intensity include younger age, dry skin, and raised or thick scars. Deep partial-thickness and full-thickness burns interrupt the function of skin appendages. Damaged skin appendages may include the apocrine sweat glands, resulting in dry, friable skin that does not heal well and is susceptible to infection.
Additionally, body temperature regulation may be compromised, with research showing how a burn patient’s rise in core body temperature following exercise is directly related to the amount of skin grafted.
Other symptoms are related to the multitude of other burn complications that will be discussed in detail in the section titled, “Potential Disease Complications.”
Physical Examination
A thorough physical examination is necessary to assess the burn itself as well as resulting complications. The evaluation should begin with an examination of the skin for burn location and depth, sensation, and signs of infection. Determination of burn depth allows categorization of wound severity.
The current burn classification system includes four categories of varying depth: superficial, superficial and deep, partial thickness, and full thickness. Superficial injuries, traditionally known as first-degree burns, solely affect the epidermal layer. The category of second-degree burns is divided into superficial and deep partial-thickness burns. Superficial partial-thickness burns interrupt the epidermis and superficial (papillary) dermis. These often have good vascular supply and are painful with a pink or red and sometimes blistered appearance. Deep partial-thickness burns extend into the deep (reticular) dermis and damage skin appendages, which affects some degree of sensory and apocrine function. Full-thickness burns, also called third-degree burns, affect the entire epidermal and dermal layers and result in complete loss of skin appendages. Deep partial-thickness and full-thickness burns usually have poor blood flow and can be painless and appear less red. Severe injuries also may penetrate to the muscle, tendon, and bone. Such deep injuries, classified as fourth-degree burns, are not part of the newer anatomic classification system ( Fig. 122.1 and Table 122.2 ).
| Classic Classification | New Classification | Appearance and Symptoms | Course and Treatment |
|---|---|---|---|
| First degree (epidermis) | Superficial thickness | Erythematous; dry, mildly swollen; blanches with pressure; painful | Exfoliation; heals spontaneously in 1 week; no scarring |
| Second degree (dermis) | Superficial partial thickness | Blistering; moist, weeping; blanches with pressure; painful | Reepithelialization in 7–20 days |
| Deep partial thickness | No blisters; wet or waxy dry; variable color; less painful; at risk for conversion to full thickness because of marginal blood supply | Reepithelialization in weeks to months; skin grafting may speed recovery; associated with scarring | |
| Third degree (all of dermis and epidermis) | Full thickness | White waxy to leathery gray to charred black; insensate to pain; does not blanch to pressure | Reepithelialization does not occur; requires skin grafting; associated with scarring |
| Fourth degree (extends to muscle, bone, tendon) | — | Black (eschar); exposed bones, ligaments, tendons | May require amputation or extensive deep débridement |
The depth of burn is an important factor in determining acute management of wounds. Burn surgeons often classify burns as superficial wounds, which heal by conservative management, or deep wounds, which require surgical intervention. Clinical assessment is the most widely used technique to evaluate burn wound depth and severity. Because of the evolving nature of burn wounds in the first few days after injury, monitoring the progression of the wound over time allows one to best assess its ultimate anatomic classification and management plan.
Postoperative burn wounds should also be closely watched in the rehabilitation setting. Postoperative wound evaluation includes inspection of grafts for hematoma, seroma, infections, and areas of graft loss. After skin grafting, and as the skin matures, one should monitor for signs of hypertrophic scarring, which initially appears as erythematous, raised, and hardened skin.
A complete neurologic examination including an assessment of motor and sensory function, reflexes, and cognition should also be performed. Immediately after injury or surgery, the sensory examination is primarily limited to light touch modality because of pain. However, after wound closure, the sensory examination enables one to evaluate for small- and large-fiber neuropathies. Deep burn wounds may involve the vascular supply and affect wound healing. A pertinent vascular examination includes assessment of peripheral pulses of the involved extremities. Because contractures are a common complication, the musculoskeletal examination should assess not only strength, but also joint range of motion and deformities. The motor examination of joints crossed by a deep partial-thickness or full-thickness burn should not be performed until after skin graft “take” is ensured, usually within a week after grafting. Note that burn patients may have significant weakness from deconditioning and loss of muscle mass. A complete cardiac and pulmonary examination should be performed with particular attention to signs of respiratory complications and hypermetabolic state. Psychiatric examination should include a thorough screening for signs of sleep disturbance, depression, anxiety, substance abuse, and post-traumatic stress. Patients who exhibit symptoms of a major psychiatric disorder should receive a complete psychiatric evaluation.
Functional Limitations
Functional limitations are directly related to the severity and location of the burn and related complications. Those with burns to the upper extremities may experience impairments in activities of daily living, fine motor tasks, and occupational activities. Burns to the lower extremities may result in impairments in mobility and higher-level exercise and sport activities. Small burns to sensitive areas such as the face, including the eyes, ears, nose, or mouth, and genitals may result in significant impairments in vision, hearing, smell, taste, feeding, and reproduction.
An important component of post-burn function, especially with the improvement in burn survival rate, is community and work reintegration. Factors associated with delayed return to work include increased hospital length of stay, electrical etiology, injury at work, and the need for inpatient rehabilitation. Further barriers for work reintegration include pain, neurologic issues, and impaired mobility. A burn-specific computer adapted test has been proposed that measures multiple dimensions of social participation and may prove helpful in future research of this topic.
Diagnostic Studies
Many different diagnostic tests are useful in the initial assessment of the burn patient. These may include tests to assess wound depth. The “gold standard” of burn depth analysis is biopsy with histologic assessment, but this is not common practice. Techniques using laser Doppler imaging, thermography, vital dyes, ultrasonography, and confocal laser scanning microscopes have been suggested for wound depth assessment, but these methods are not routinely used clinically. Bronchoscopic evaluation of the airway as well as serum carboxyhemoglobin level are used to assess for inhalation injury.
In the rehabilitation setting, diagnostic tests are targeted toward short- and long-term sequelae of burns. Doppler ultrasound is the recommended screening technique for detection of deep venous thrombosis given its high specificity and sensitivity. D-dimer has not been shown to be efficacious in deep vein thrombosis (DVT) screening in burn patients, with one study showing specificity of 20% and positive predictive value of 5%. Plain radiographs are used to evaluate for abnormal bone and joint changes, such as bone growth deformity in children, osteophytes, or joint subluxation and dislocation. Plain films are also used to evaluate heterotopic ossification (HO) but may not demonstrate findings until 3 weeks (see Chapter 131 ). HO is diagnosed as early as 7 days after formation with a triple-phase bone scan. The aberrant ossification is visualized by increased uptake in the third phase of the scan. For patients with signs or symptoms of peripheral nerve injury, nerve conduction study and electromyography are used for the diagnosis of neuropathy.
Thermal injury
Electrical burns
Chemical burns
Radiation burns
Scalding
Treatment
Initial
The initial management of the severely burned patient focuses on the ABCs: airway, breathing, and circulation. Aggressive fluid resuscitation to compensate for insensible fluid losses is a mainstay of acute management. However, scientific studies have shown that overresuscitation is a complication with grave consequences, including extremity and abdominal compartment syndrome, respiratory failure, and ocular hypertension. Other principles of initial management include maintenance of clean and protected wounds, use of antimicrobial agents and infection prevention, emergent relief of ischemic compression by fasciotomy or escharotomy, and early excision and grafting of open wounds. A detailed review of the rapid advances in acute management of burn injuries is beyond the scope of this chapter.
Rehabilitation
Rehabilitation of burn patients is a complex process. The most common and significant issues are discussed in this section.
Pain
Pain management after burn injury is an integral part of rehabilitation. Background nociceptive pain from the injury itself and exacerbations of pain from therapy, dressing changes, débridement, and other procedures can cause significant discomfort. Long-acting opioid pain medications are commonly used to treat background pain. Premedication with short-acting opioid analgesics before dressing changes or procedures and for breakthrough pain is standard of care. Opioid agonist-antagonist drugs (e.g., nalbuphine and butorphanol) have been shown to be effective in treating burn-related pain, but research is limited. Given the growing awareness of opioid abuse in society, a plan for tapering these addictive medications and utilizing adjuvant medications and nonpharmacologic strategies is an important component of pain management strategy. Even nonsteroidal anti-inflammatory drugs and acetaminophen can be valuable for pain control in combination with opioids. Antidepressants, anticonvulsants, and clonidine have been proposed as potential analgesic agents, but have yet to been studied in burn patients specifically.
Multiple studies have demonstrated a reduction of pain scores with the following techniques: massage, hypnosis, multimodal distraction techniques, and cognitive-behavioral techniques. Additionally, off-the-shelf virtual reality and music therapy have both been shown to reduce acute pain intensity during wound care procedures.
Clinicians should note that pain is often a multifactorial experience and therefore should make extended efforts to treat all possible contributing factors, including pruritus, neuropathy, anxiety, sleep disturbance, depression, and post-traumatic stress.
Pruritus
Moisturizing is encouraged for treatment of pruritus; not only do emollients such as aloe vera and lanolin help improve skin quality, but massaging may provide itch relief by the gate theory and desensitization of the skin. Studies have also shown that topical treatments with colloidal oatmeal, liquid paraffin, eutectic mixture of local anesthetics application, and doxepin cream can be effective for symptom management.
A mainstay of treatment is antihistamines. Histamine is found in abundance in burn wounds and is implicated as a primary mediator of pruritus. Selective H 1 and H 2 antihistamines are generally preferred to nonspecific antihistamines for their limited side effect profile. The use of cetirizine and cimetidine was also shown to be more effective than diphenhydramine and placebo in treatment of post-burn pruritus. However, the effect of any antihistamine is often limited. A study of 35 adult patients using diphenhydramine, hydroxyzine, and chlorpheniramine showed similar effect with complete relief in only 20%, partial relief in 60%, and no relief in 20% of patients.
Gabapentin has been shown in studies to relieve pruritus, both as monotherapy and in combination with antihistamines. It is thought to have anti-pruritic effects by blocking post-synaptic calcium channels and inhibiting neurotransmitter synthesis. A comparative study of gabapentin, cetirizine, and the combination of the two in 60 patients showed significantly better results in the gabapentin group and the combination group compared with the cetirizine-only group. Similarly, a double-blinded randomized placebo controlled study ( n = 80) compared pregabalin to cetirizine, a combination of both, and placebo. The pregabalin and combination groups both showed a reduction in itch for almost 95% of participants. Other agents including ondansetron, paroxetine, and naltrexone have shown potential usefulness as adjunctive treatments.
Biofeedback therapy and psychological support may attenuate symptoms. Modalities including laser treatment, massage, and transcutaneous electrical nerve stimulation have also demonstrated positive results and may be useful. A recent prospective study performed reported positive preliminary results with the use of botulinum toxin injection, but this treatment is still under investigation.
Wounds
The goal of wound care is to provide a moist, clean environment for reduced bacterial colonization and re-epithelialization. Silver-based dressings are the cornerstone of wound management because silver ions have broad antimicroorganism activity. Silver sulfadiazine is the best known and most widely used silver-based agent for burns. More recent research suggests that new dressings that elute nanocrystalline silver have better antimicrobial activity, including against methicillin-resistant Staphylococcus aureus . These dressings allow longer intervals between dressing changes and increase the patient’s comfort. Hydrofiber dressings are another new dressing type that may be less painful and are commonly used for exudative burns. There has also been increasing interest in honey. Several clinical trials comparing honey with traditional dressing in minor burns showed shorter healing times. In general, there are many dressing options, and dressing selection should take into account knowledge and familiarity of the health care providers.
Deep Venous Thrombosis
A randomized control trial by Ahuja et al. supports routine chemoprophylaxis with low molecular weight heparin (0.5 mg/kg twice daily, max 60 mg/daily) for DVT prevention in burn patients.
Hypertrophic Scarring
Compression garments are considered standard of care for treatment of hypertrophic scars. Such garments are initiated with closure of wounds. Initially, pressure wrappings are applied around the affected areas with plastic elastic (ACE), cotton elastic (Tubigrip), or adhesive elastic (Coban) bandages. As edema resolves, the scarred area assumes a more stable shape, and custom-made pressure garments are then fitted. These garments are usually recommended to be worn 23 hours per day for up to 1 to 2 years after a burn. Compliance with this schedule is difficult for many patients. The efficacy of this treatment has not been established, but a number of studies show some improvement in clinical appearance in patients with moderate or severe scarring. Silicone gel sheeting is also considered first-line treatment, and a systematic review recently published further supports their use for immature epithelialized burn wounds at high risk for hypertrophic scarring. Other adjunctive therapies for scarring include laser treatment, intense pulsed light, steroids, exercise, and injection of fat, but there is little evidence surrounding each of these modalities.
Contractures
Positioning and splinting are used to prevent development of contractures and to maximize joint function. Preventive treatment ideally begins on admission to the intensive care unit. The optimal position to minimize contracture development is depicted in Fig. 122.2 . Particular attention is given to burns that cross joints and exposed tendons. Such joints are at high risk for contracture development. A system of cutaneous functional units (CFUs) has been created based on the fact that the amount of skin involved in joint movement extends far beyond the immediate proximity of the joint creases themselves. For example, the CFUs for the action of neck extension include the skin from the sternal notch to the pubic bone. The CFU system helps determine the areas of damaged skin, both proximal and distal, that could potentially contribute to joint contractures. This system may be helpful in promoting contracture prevention techniques in these high-risk areas, such as empirical splinting and ranging of joints. Range of motion exercises can begin immediately if the patient has not undergone skin grafting and usually within 1 week after grafting so as not to interfere with graft take. Once a contracture develops, rehabilitation interventions such as splinting, positioning, range of motion exercises, and serial casting have been shown to prevent worsening of the contracture and to improve joint motion.
