C h a p t e r 4 6
Disorders of Skin Integrity and Function
1169
These burns heal with supportive medical care aimed at
preventing further tissue damage, providing adequate
hydration, and ensuring that the granular bed is ade-
quate to support re-epithelialization.
Third-degree full-thickness burns
extend into the
subcutaneous tissue and may involve muscle and bone.
Thrombosed vessels can be seen under the burned skin,
indicating that the underlying vasculature is involved.
Third-degree burns vary in color from waxy white or
yellow to tan, brown, deep red, or black. These burns are
hard, dry, and leathery. Edema is extensive in the burn
area and surrounding tissues. There is no pain because
the nerve sensors have been destroyed. However, there
is no such thing as a “pure” third-degree burn. Third-
degree burns are almost always surrounded by second-
degree burns, which are surrounded by an area of
first-degree burns. The injury sometimes has an almost
targetlike appearance because of the various degrees of
burn. Full-thickness burns wider than 1.5 inches usu-
ally require skin grafts because all the regenerative (i.e.,
dermal) elements have been destroyed. Smaller injuries
usually heal from the margins inward toward the cen-
ter, the dermal elements regenerating from the healthier
margins. However, regeneration may take many weeks
and leave a permanent scar, even in smaller burns.
In addition to the depth of the wound, the extent of
the burn also is important. Extent is measured by esti-
mating the amount of total body surface area (TBSA)
involved.
49,50
Several tools exist for estimating the TBSA.
For example, the
rule of nines
counts anatomic body
parts as multiples of 9% (the head and neck is 9%, each
arm 9%, each leg 18%, anterior trunk 18%, posterior
trunk 18%), with the perineum 1%. The Lund and
Browder chart includes a body diagram table that esti-
mates the TBSA by age and anatomic part. Children are
more accurately assessed using this method because it
takes into account the difference in relative size of body
parts. The estimates of TBSA are then converted to the
American Burn Association Classification of Extent of
Injury (Table 46-1).
Other factors, such as age, location, other injuries,
and preexisting conditions, are taken into consideration
for a full assessment of burn injury.
49,50
These factors can
increase the assessed severity of the burn and the length of
treatment. For example, a first-degree burn is reclassified
as a more severe burn if other factors are present, such as
burns to the hands, face, and feet; inhalation injury; other
trauma; or existence of psychosocial problems. Genital
burns almost always require hospitalization because
edema may cause difficulty urinating and the location
complicates maintenance of a bacteria-free environment.
Systemic Complications
Burn victims often are confronted with hemodynamic
instability, impaired respiratory function, a hypermeta-
bolic response, and sepsis.
49,50
The magnitude of the
response is proportional to the extent of injury, usu-
ally reaching a plateau when approximately 60% of the
body is burned. In addition to loss of skin, burn victims
often have associated injuries or illnesses. The treatment
challenge is to provide immediate resuscitation efforts
and long-term maintenance of physiologic function.
Pain and emotional problems are additional challenges
faced by persons with burns.
Hemodynamic Instability.
Hemodynamic instabil-
ity begins almost immediately with injury to capillar-
ies in the burned area and surrounding tissue. Fluid is
lost from the vascular, interstitial, and cellular compart-
ments. Because of a loss of vascular volume, major burn
victims often present in the emergency department in a
form of hypovolemic shock (Chapter 20) known as
burn
shock
. Because proteins from the blood are lost into the
interstitial compartment, generalized edema, including
pulmonary edema, can be severe.
TABLE 46-1
American Burn Association Grading System for Burn Severity and Disposition
Type of Burn
Minor
Moderate
Major
Criteria
<10%TBSA in adult
10%–20%TBSA in adult
>20%TBSA in adult
<5%TBSA in young (<10 years) or
old (>50 years)
5%–10%TBSA in young or old >10%TBSA in young or old
<2% Full-thickness burn
2%–5% Full-thickness burn
>5% Full-thickness burn
High-voltage injury
High-voltage burn
Suspected inhalation injury
Known inhalation injury
Circumferential burn
Any significant burn to face, eyes, ears,
genitalia, hands, feet, or major joints
Concomitant medical problem
predisposing to infection (e.g.,
diabetes, sickle cell disease)
Significant associated injuries (e.g.,
major trauma)
Disposition
Outpatient management
Hospital admission
Referral to burn center
TBSA, total body surface area.
From American Burn Association. Hospital and prehospital resources for optimal care of patients with burn
injury: guidelines for development and operation of burn centers. J Burn Care Rehabil. 1990;11:98–104.
