BURNS
BURNS
■ tissue damage and cell death caused
by intense heat, electricity, UV
radiation (sunburn), or certain
chemicals (such as acids), which
denature proteins and cause cell
death in the affected areas.
TWO LIFE-THREATENING
PROBLEMS:
1. The body loses its precious supply of
fluids
• Dehydration and electrolyte imbalance
follow
2.Infection
RULE OF NINES
■ 11 areas (each accounting for 9% of
the total body surface area, plus an
additional area surrounding the
genitals (the perineum) representing
1 percent of body surface area)
CLASSIFICATION OF BURNS
according to their severity
1. First-degree (superficial)
2. Second-degree (superficial partialthickness burns)
3. Third-degree (full-thickness burns)
4. Fourth-degree (full-thickness burns with
deep-tissue involvement)
FIRST-DEGREE BURNS
■ only the superficial epidermis is damaged
■ red and swollen
■ generally heal in 2-3 days
■ Example: Sunburn without blistering
SECOND-DEGREE BURNS
■ the epidermis and the superficial part of
the dermis is damaged
■ red, painful, and blistered
■ regeneration can occur
THIRD-DEGREE BURNS
■ both the epidermis and the dermis is
damaged and often extend into the
subcutaneous tissue
■ blistered, blanched, or blackened
■ not painful
■ regeneration is not possible
FOURTH-DEGREE BURNS
■ full-thickness burns, but they extend into
deeper tissues
■ dry and leathery
■ require surgery and grafting
■ in severe cases, amputation may be
required
In general, burns are considered critical
if any of the following conditions exists:
■ Over 30 percent of the body has second-degree burns.
■ Over 10 percent of the body has third- or fourth-degree burns.
■ There are third- or fourth-degree burns of the face, hands, feet,
or genitals.
■ Burns affect the airway.
■ Circumferential (around the body or limb) burns have occurred.
– Facial burns are particularly dangerous because of the
possibility of burns in respiratory passageways, which can
swell and cause suffocation.
– Circumferential burns can restrict movement, and
depending on location, can interfere with normal breathing.
TISSUE REPAIR
Wound Healing
1. Inflammation sets the stage.
■ Injured tissue cells and others release
inflammatory chemicals that make the
capillaries very permeable. A fluid rich in
clotting proteins construct a clot to stop
blood loss and hold the edges of the wound
together. When the clot is exposed to air,
it quickly dries and hardens and forms a
scab.
2. Granulation tissue forms.
■ A delicate pink tissue (granulation tissue)
composed of largely new capillaries, forms
on the surface of the wound when wound
is healing. It gets its red color from the
new blood vessels that are forming to
deliver nutrients to the tissue. This tissue
contains phagocytes, which eventually
dispose of the blood clot, and connective
tissue.
3. Regeneration and fibrosis.
■ The surface epithelium begins to
regenerate and makes its way between
the granulation tissue and the scab. Its
final result covers an underlying area of
fibrosis (scar), and the scar is either seen
invisible or visible as a thin white line
which depends on the severity of the
wound.