Burn Wound Care
PREREQUISITE NURSING KNOWLEDGE
• Burns destroy the structural integrity of the skin, disrupting its normal functions of regulating temperature, maintaining fluid status, protecting against infection, covering nerve endings, and establishing identity.2 The skin is composed of two layers, the epidermis and the dermis, and is supported by a subcutaneous layer that is rich in blood vessels (Fig. 120-1).
The epidermis is the outermost layer. It is capable of rapid regeneration through division of cells closest to the dermis; older epidermal cells are pushed outward as the epidermis is regenerated. The epidermis provides a barrier to the environment, containing melanocytes (protection from the sun) and Langerhans cells (protection against foreign organisms).
The dermis contains blood vessels, sensory fibers (for pain, touch, pressure, and temperature), collagen, sebaceous glands, and sweat glands. Epidermal cells line deep dermal structures (hair follicles and sweat glands); these epidermal elements provide the ability for the skin to regenerate (the more epidermal cells remaining in the wound bed, the faster the healing).
• The depth of burns has historically been classified as first-degree (into epidermis), second-degree (into dermis), or third-degree (through skin into subcutaneous tissue; Table 120-1).1,2
Table 120-1
Depth Characteristics of Burn Wounds
Type | Physical Characteristics | Healing |
Superficial burn (first-degree): Destruction of epidermis, usually caused by overexposure to sun or brief exposure to hot liquid. This type of injury is not included in calculation of burn size. | Red; hypersensitive; no blisters. | Injured layers peel away from totally healed skin at 5 to 7 days without residual scarring. |
Superficial partial-thickness burn (superficial second-degree): Destruction of epidermis and upper dermis. Usually results from scalding or brief contact with hot objects. | Blistered; very moist; red or pink in color; exquisitely painful; capillary refill intact. | Reepithelializes from epidermal appendages in 7 to 14 days. Usually has minimal scarring but variable repigmentation. |
Deep partial-thickness burn (deep second-degree): Destruction of epidermis through to lower dermis. May result from grease or longer contact with hot objects. | Mottled pink to white; drier than superficial burns; less sensitive to pinprick; does not blanch to pressure; hair follicles and sweat glands intact. | Slower regeneration from epidermal elements: 14 to 21+ days in absence of grafting. Prone to hypertrophic scars and contracture formation. May require grafting to reduce healing time and complications. |
Full-thickness burn (third-degree): Destruction of epidermis and all of dermis. Results from exposure to flames, chemicals that are not immediately washed, electrical injury, or prolonged contact with heat source. | Dry; leathery and firm to touch; pearly white, brown, or charred in appearance; no blanching to pressure; no pain, may see thrombosed vessels. | Incapable of self-regeneration. Preferred treatment is early excision and autografting. |
First-degree, or superficial, burns extend only partially through the epidermis, thereby maintaining the barrier function of the skin. These burns are not included when estimating the percentage of total body surface area burned (%TBSA) because they do not result in an open wound.
Second-degree burns extend into the dermis and can be superficial (loss of the epidermis and part of the dermis) or deep (destruction of most of the dermis). They are also referred to as partial-thickness burns because they extend partially through the skin (Fig. 120-2). These wounds heal by epithelialization from epidermal cells remaining in the dermis. Shallow wounds are associated with rapid healing and less scarring. Deep wounds may result in slow-healing (more than 21 days) and fragile wounds prone to hypertrophic scarring. For that reason, surgical excision of partial-thickness wounds that affect functional and cosmetic areas and application of skin grafts may be preferable.
A third-degree, or full-thickness, burn involves complete destruction of the dermis. Because the skin is unable to regenerate, the dead tissue is removed and the wound is grafted with skin from another part of the patient’s own body (autograft).2 The grafted wound loses epidermal appendages and is unable to sweat, maintain lubrication, or protect from sun exposure after healing (Fig. 120-3).
• The depth of a burn wound is directly related to the temperature intensity and the duration of contact with the burning agent. The burning agent can be thermal (i.e., flame, contact, or scald), chemical, or electrical. An inhalation injury should always be suspected if the patient was in an enclosed space with a fire; mortality rate is significantly increased when burns are compounded by smoke inhalation.4
• The burn injury produces three zones of injury: the zone of coagulation (cellular death), zone of stasis (vascular impairment, potentially reversible tissue injury), and zone of hyperemia (increased blood flow and inflammatory response). Decreased perfusion of the burn wound can cause the zone of stasis to deteriorate, deepening the initial wound. This progressive destruction can be minimized by providing adequate oxygenation and fluid resuscitation, alleviating pressure on the injured tissue, maintaining local and systemic warmth, and decreasing edema by elevating the burned area.1
• Assess for areas where full-thickness eschar is circumferential. Because of the inelastic nature of eschar, it may act like a tourniquet as edema develops, requiring surgical release (escharotomy) to prevent circulatory or respiratory compromise (Fig. 120-4).
Figure 120-4 Escharotomy of the leg to improve circulation.
• Monitor pulses, capillary refill, and sensation distal to circumferential eschar. Signs and symptoms that indicate a need for escharotomy include cyanosis of distal unburned skin, unrelenting deep tissue pain, progressive paresthesias, and progressive decrease or absence of pulse.1
• Adequacy of respiratory excursion must be assessed because circumferential eschar of the trunk can lead to decreased tidal volume and agitation (Fig. 120-5).1
• Escharotomy is performed at the bedside by a physician, with a scalpel or electrocautery used to cut the eschar longitudinally. Bleeding should be minimal because only dead tissue is cut; any bleeding can be controlled with sutures, silver nitrate sticks, collagen packing, or electrocautery. Pain is usually managed with small intravenous doses of opiates and benzodiazepines.
• Burn size may be determined with several methods.20
The rule of nines may be used to quickly calculate burn size. In an adult, the head and neck and each upper extremity represent 9% of the patient’s body surface area. The anterior trunk, posterior trunk, and each leg represent 18% of the patient’s body surface area. This rule only applies to adults; infants and young children have much larger heads in proportion to body size.
The Lund and Browder chart (Fig. 120-6) breaks the body into smaller areas and takes into consideration the proportional differences of persons of different ages.12
Figure 120-6 The Lund and Browder chart is used to assess and graphically document size and depth of the burn wound.
The rule of the palm notes that the patient’s hand may be used as a template to represent roughly 1% of the TBSA.
• The inflammatory response causes a massive fluid shift to the interstitial space during the first 24 hours, with mobilization of fluid starting after 72 hours. Fluid resuscitation with a balanced salt solution is based on the patient’s weight and burn size (partial-thickness and full-thickness wounds).17 Large wounds are prone to huge evaporative water losses that require close monitoring of volume status.
• Effective resuscitation results in adequate urinary output (30 to 50 mL/hr or 0.5 to 1.0 mL/kg/hr) and mean arterial blood pressure of at least 60 mm Hg as surrogate markers of end-organ perfusion and hemodynamic stability.17
• Burns of specific anatomic areas need special consideration. Assess eyes for injury and treat chemical exposure with copious normal saline solution irrigation; treat burned ears with a topical antimicrobial cream and protect from pressure by eliminating use of pillows or dressings about the head; elevate burned extremities; consider the need for an indwelling urinary catheter in the patient with perineal burns; and shave hair growing through the burn wounds. Two burned surfaces that contact each other need dressings between them to prevent fusing as they heal (e.g., between toes, skin folds).
• Emergency treatment of thermal injuries includes initially cooling the burned skin with tepid water (never with ice) while recognizing the importance of preventing hypothermia.1 In preparation for transfer, the airway should be assessed and 100% oxygen administered; large-bore intravenous (IV) access should be established and fluid resuscitation started; patients should be on nothing by mouth (NPO) status; wounds should be wrapped with a clean, dry sheet and possibly blanket; pain medication should be given in small IV doses, with recognition that coexisting injuries or medical conditions exacerbate the effects of opiates; tetanus prophylaxis should be administered; and all initial treatment should be documented.1
• Initial treatment of chemical burns includes removing saturated clothing, brushing off any powdered chemical, and continuously irrigating involved skin with copious amounts of water for 20 to 30 minutes. Neutralizing chemical burns with another chemical is contraindicated because the procedure generates heat. Burned eyes must be irrigated with large volumes of normal saline solution followed by an eye examination.1 Some chemicals are absorbed systemically through burn wounds; contact the local poison control center to determine whether further treatment is indicated.2 Ensure all providers wear appropriate personal protective equipment to prevent unintentional chemical exposure.
• Tar can be removed with mineral oil, a petrolatum-based ointment, or solvent.16
• Electrical injuries (Fig. 120-7) result when the body becomes part of the pathway for the electrical current. Deep burns may occur from tissue resistance where the patient contacted the electrical source and where the patient was grounded. Initially of greater concern than the burns is the high incidence of cardiac dysrhythmias, myoglobinuria resulting in acute tubular necrosis, and neurologic sequelae. Monitoring electrocardiographic (ECG) results, increasing urine output to 100 mL/hr in the presence of dark port-colored urine, assessing for associated trauma, and establishing baseline neurologic status are vital in the treatment of the electrical injury patient.1,20