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BURNS AND WOUNDS 451

has one or more of the following: (I) altered mental status; (2) burns

on the face, neck, or upper chest; (3) singed eyebrows or nose hairs;

(4) laryngeal edema; (5) arterial blood gas levels consistent with

hypoxia; (6) abnormal breath sounds; (7) the presence of soot in sputum; or (8) positive blood test results for chemicals.

The oropharynx and tracheobronchial tree are usually damaged by

thermal injury, whereas the lung parenchyma is damaged by the

chemical effects of the inhalant. Thermal airway injury is characterized by immediate upper-airway mucosal edema, erythema, hemorrhage, and ulceration.' Elective endotracheal intubation is indicated with this type of injury, as progressive edema can readily lead to airway obstruction. The patient remains intubated until airway edema is decreased, usually 2-4 days post injury.17

The pathophysiology of inhalation injury generally occurs in

three stages: ( 1) inhalation injury (0-36 hours afrer injury), (2) pulmonary edema (6-72 hours after injury), and (3) bronchopneumonia (3-10 days after injury). Pulmonary edema occurs from increased lung capillary permeability, increased bronchial blood

flow, and impaired lymph function." There are de-epithelialization

and exudate formation throughout the airways, as well as

decreased alveolar surfactant' Decreased lung compliance (functional residual capacity and vital capacity) and hypoxia are the primary effects of inhalation injury, each of which is dependent on the location and severity of the injury. Supplemental oxygen, elective

intubation, bronchodilators, and fluid resuscitation are initiated to

maximize gas exchange and reverse hypoxia.19-21

The inhalation of CO, which is a colorless, odorless, tasteless,

combustible, nonirritating gas produced by the incomplete combustion of organic material, results in asphyxia. CO molecules displace oxygen molecules from hemoglobin to form carboxyhemoglobin and

shift the oxyhemoglobin curve to the left, thereby decreasing the

release of oxygen. Additionally, CO molecules increase pulmonary

secretions and decrease the effectiveness of the mucociliary elevator.22

Elevated carboxyhemoglobin levels cause headache, disorientation,

nausea, visual changes, or coma, depending on the percentage. CO

poisoning is usually reversible with the use of 100% oxygen if the

patient has not lost consciousness.4

Burn Care in the Resuscitative Phase

During the first 72 hours after a burn injury, medical management

consists of continued fluid resuscitation, infection control, body

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AClHE CARE HANDBOOK FOR PHYSICAL THERAPISTS

temperature maintenance, pain and anxiety management, and initial burn carc.

Fluid Resuscitation

After a burn, fluid shifts from vascular to interstitial and intracellular spaces because of increased capillary pressure, increased capillary and venular permeability, decreased interstirial hydrostatic pressure, chemical inflammatory mediators, and increased interstitial protein retention.23 This is compounded by evaporative water loss from a disruption of the skin." In burns of more than 20%

TBsA, this fluid shift becomes massive and requires immediate

fluid repletion.1J This fluid shift, referred to as bum shock, is a

life-threatening condition because of hypovolemia and the potential for shock induced renal failure Isee Figure 7-3). Plasma, sodium-rich solutions, and other fluids are infused over a 48-hour

period according to a standard formula derived from individual

TBsA and body weight. The formula used varies according ro hospital preference.

During and after fluid administration, the patient is monitored

closely for adequacy of fluid resuscitation. Heart rate, blood pressure, cardiac output, base deficit, urine output, and bowel sounds provide valuable information about the effectiveness of fluid resuscitation, as do peripheral body temperature, capillary refill, and mental status.23

Infection Control

Prevention of infection at the burn site(s) is crucial in the resuscitative

and reparative phases of burn care. The patient with a major burn is

considered immunocompromised because of the loss of skin and the

inability to keep micro-organisms from entering the body. Infection

control is achieved by the foliowinglJ;

• Observation of the patient for signs and symptoms of sepsis Isee

Sepsis in Chapter 10. )

• Minimization of the presence of micro-organisms in the

patient'S internal and external environment

• Use of aseptic techniques in all interactions with the patient

• Use of topical antimicrobial agents or antibiotics, as needed

• Tetanus prophylaxis

BURNS AND WOUNDS

453

Clinical Tip

To minimize the risk of infection, the physical therapist

must use sterile techniques according to the burn unit procedures when entering a patient'S room or approaching the

patient'S bedside. The physical therapist should be familiar

with the institution's policies regarding the use and disposal of protective barriers, such as gloves, gowns, caps, and masks.

Body Temperature Maintenance

The patient with a major burn injury is at risk for hypothermia from

skin loss and the inability to thermoregulate. Body heat is lost

through conduction to the surrounding atmosphere and to the surface

of the bed. Initially, dry dressings may be placed on the patient to

minimize heat loss. The patient should be placed in a warm atmosphere to maintain body temperature. The patient'S room, burn unit, or both may have overhead radiant heat panels and may be humidified in an effort to preserve the patient's body heat.

Pain Management

A parienr with a burn injury can experience pain as a result of any of

the following:

• Free nerve ending exposure

• Edema

• Exudate accumulation

• Burn debridement and dressing changes

• Mobiliry

• Secondary injury, such as fracture

Patients may also experience fear from the injury and burn treatment,

which can exacerbate pain. Analgesia, given intravenously, is therefore started as soon as possible (see Appendix VI).

Initial Burn Care

To neutralize the burn source, the patient'S clothing and jewelry are

removed, and the burn is rinsed or lavaged (for a chemical burn). Ini-

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AClITE CARE HANDBOOK FOR PHYSICAL THERAI'ISTS

tially, a burn is debrided, cleaned, and dressed with the hospital's or

burn unit's antimicrobial agent of choice once the patient is scabilized

from a cardiopulmonary perspective. Topical antimicrobial agents

attempt to prevent or minimize bacterial growth in a burn and expedite eschar separation. There is a variety of antimicrobial agents, each with its own application, advantages, and disadvantages. Ideally, the

antimicrobial agent of choice should penetrate eschar, work against a

wide variety of micro-organisms, have minimal systemic absorption,

and not impede healing." The physician determines whether to cover

the burn or Leave it open and estimates the time frame for burn repair,

rhe need for surgical intervention, or both.

Escharotomy and Fasciotomy

Circumferential burns of the extremities or trunk can create neurovascular complications. Inelastic eschar paired with edema can cause increased tissue swelling in all directions with the result of

decreased blood flow, nerve compression, and increased compartment