0071643192.pdf

■ Partial-thickness 15–25% in 10- to 50-year-olds
■ Partial-thickness 10–20% in <10- or >50–years old
■ Full-thickness 2–10%
■ Minor: Outpatient
■ Partial thickness <15% in 10- to 50-year-olds
■ Partial thickness <10% in <10- or >50-year-olds
■ Full thickness < 2%

Chemical Burns

The classes of burning chemicals include acids, alkalis, oxidizing agents,
corrosives, reducing agents, desiccants, vesicants, protoplasmic poisons
(see Table 3.14).

■ Acids cause coagulative necrosis,creating a tough eschar preventing deep
penetration of burn.
■ Alkalis cause liquefactive necrosis, a poor barrier, so burns travel much
deeper. For this reason, alkali burns tend to be worse than acid burns.
■ Cementcontains lime, which is converted with water to the alkali calcium
hydroxide.

TREATMENT

■ The first line in chemical-burn therapy is ample irrigation to remove the
offending agent, except with
■ Dry powder (lime): Brush away before hydration.
■ Sodium metals: Use oil, not water.
■ Phenol (carbolic acid)
■ Be careful of heat production when chemicals react with water or their
neutralizing agents.
■ Lacrimators (tear gas and pepper spray) irritate mucosa (eye, nose, and
mouth) and are treated with copious water irrigation.
■ Airbag deployment utilizes an exothermic reaction that can cause burns
(sodium azide) and keratitis (sodium hydroxide). These are treated with
thorough irrigation with water.

BALLISTICS

Bullets cause injury by crush (permanent cavitation) and by temporary cavita-
tion (tissue stretch).

Characteristics that determine injury pattern:

■ Bullet mass: Determines depth of penetration and diameter of crush
injury.
■ Bullet construction: Increased deformity or fragmentation (hollow point
bullets and lead bullets without a cap) yields great crush injury.
■ Bullet yaw (tilt off long axis): Greater yaw yields greater crush injury.
■ Bullet velocity: Higher velocity yields greater cavitation.
■ Shorter gun barrels produce lower velocity because the expanding
gases are released into the atmosphere sooner.
■ As a result, handguns fire low-velocity bulletsand do not produce sig-
nificant cavitation.

TRAUMA

Common alkalis (“lyes”)

include drain and toilet

cleaners, detergents, cement,

and paint removers. Treat with

copious irrigation.

Glass etching=>

hydrofluoric acid burn=>

treat with calcium gluconate.

The skin often looks normal

and pain may not begin for

hours after exposure.

Chemical burns to the eyes

are emergencies and require

immediate and copious

irrigation to restore ocular pH

to 7.3–7.7.

The primary treatment for

almost all chemical exposures

except metals, dry powder

lime, and phenol is water

irrigation.