Acids are proton donors, so they release
hydrogen ions and reduce pH from a neutral 7
down to values as low as 0. Hydrogen ions will
catalyse protein hydrolysis into amino acids.
Other effects as seen in concentrated sulfuric
acid injuries include heat generation and
desiccation, producing a mixed injury.
Tungstic, picric, sulfosalicylic, tannic,
trichlopacetic, and cresylic acids are all
strong protoplasmic poisons which form hard
eschars. These acids can be absorbed producing
renal and hepatic injury. Most have a very
pungent odor.
Multiple chemical agents are involved in
caustic alkali burns. Lime, potassium hydroxide,
and sodium hydroxide are the most common agents
causing chemical injury. Accidental injury
occurs in infants and toddlers. Among chemical
burns, alkali injuries occur frequently and are
likely to cause severe symptoms. The mechanism
by which these alkali injuries are caused is due
to three factors:
- saponification of fat causes fatty tissue
to lose its function with increased damage
due to heat reaction.
- extraction of water from cells causing
dessication
- bind with the proteins of the tissues to
form alkaline proteinates.
The extent of the damage caused by an alkali
substance depends on its concentration, amount,
and time of contact with the skin.
As with other chemical burns, alkalis are
capable of deep penetration, and can cause
severe pain. For treatment, it is necessary to
remove the causative substance as quickly as
possible by washing with large volumes of water.
Washing is presumed to cause dilution and
elimination of a chemical substance.
The initial treatment for burns caused by
strong alkaline solution is copious irrigation
with water. Water may dissipate any heat by
dilution so as to prevent further damage. In
lime burns, the dry lime must be brushed away
before washing in order to minimize the
production of heat. The most readily available
material for removing a chemical agent is water,
and it is extremely important to remove a
chemical agent as
rapidly as possible. Washing with large
quantities of water is the preferred treatment.
It is very difficult to determine the depth of
tissue damage on admission. The corrosive
material blackens the skin, rapidly converting
it to a hard, dry eschar.
Ocular damage is a common sequel to alkali
injury. Damage is related to the pH: the higher
the pH, the greater the damage to the eye. The
corrosive agent trickles down the eyelid and
enters the acanthi. Alkalis penetrates quickly
and, with little resistance.
Such damage may be made worse by repeated
attempts to wipe off the chemical agent with the
hands or inadequately washing the eyes. The
policy is to treat with topical anesthetics
followed by copious irrigation, inducation of
cycloplegia and mydriasis as soon as possible.
Treatment -- Alkali Burn
- brush off any alkali powder (lime)
- copious irrigation with water
- reassess to determine depth
- monitor body Temp. to keep warm
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