The American Burn Association estimates that 500,000 individuals
are treated for burns in the U.S. annually. Of these, 40,000 require
hospitalization.1 Thus, the majority of burn patients
are treated and discharged from the ED to be followed as outpatients.
More than 60% of those hospitalized are admitted to the
125 specialized burn treatment centers, and the others are cared
for in community hospitals. Fire and burn deaths account for about
4000 deaths each year.1
The risk of burns is highest in the 18- to 35-year-old age group.
There is a male-female ratio of 2:1 for both injury and death. The
incidence of scalds from hot liquids is higher in children 1 to
5 years of age and in the elderly. The death rate in patients >65
years of age is much higher than that in the overall burn population.2,3
Significant strides have been made in the overall care of burn
patients during the last two decades.4,5 These
advances are reflected in a decreased mortality rate among patients
with major thermal injury; only about 4% of those treated
in specialized burn treatment centers die from their injuries or
associated complications.6 The incidence of inpatient admissions
has decreased over time owing to improvements in outpatient care
both in the ED and in the burn unit. The risk of death from a major
burn increases with larger burn size, older age, the presence of
inhalation injury, and female sex.3
Skin consists of two layers: the epidermis and the dermis (Figure 210-1). Skin thickness is less in
the very young and the elderly. It also varies significantly throughout
the body. The skin is
very thick on the palms of the hands and the soles of the feet.
The skin on the upper part of the back is thicker than that on other
parts of the body. Thus exposure to the same temperature for the
same duration leads to different depths of injury on different parts
of the body.
Layers of the skin. (Courtesy of Mary Myrand, Wayne State
University School of Medicine, Bio-Medical Communications Department.)
Skin functions as a semipermeable barrier to evaporative water
loss. Other functions of the skin include protection from the adversities
of the environment, control of body temperature, sensation, and
excretion. Partial-thickness thermal injury can result in disruption
of the barrier function and contribute to free water deficits. The
effect may be significant with moderate to large burns.
Thermal injury results in a spectrum of local and systemic homeostatic derangements
that contribute to burn shock (Table 210-1).
These include disruption of normal cell membrane function, hormonal
alterations, changes in tissue acid-base balance, hemodynamic changes,
and hematologic derangement.
210-1 Physiologic Effects of Thermal Injury