Biomedical Engineering Reference
In-Depth Information
Table 6.3
Nerve agent effects—vapor exposure
Severity
Symptoms
Onset
Treatment
Mild/moderate
Eyes
Miosis
Seconds to
minutes
Atropine eye drops
Dim vision
Atropine (IV or IM)
Headache
Oximes (IV or IM)
Nose
Rhinorrhea
Mouth
Salivation
Lungs
Dyspnea
Severe
Severe difficulty breathing or apnea
Generalized muscle twitching, weakness
or paralysis Loss of bowel or bladder control
Convulsions Loss of consciousness
Seconds to
minutes
Atropine (IV)
Oximes (IV)
Diazepam (IV)
Table 6.4
Nerve agent effects—liquid exposure
Severity
Symptoms
Onset
Treatment
Mild/moderate Muscle fasciculations and sweating
at exposure site
Nausea and vomiting
Weakness
Minutes to
18 hours
Atropine (IV or IM)
Oximes (IV or IM)
Severe
Difficulty breathing or apnea
Muscle twitching, weakness or paralysis
Loss of bowel or bladder control
Convulsions
Loss of consciousness
Minutes to
1 hours
Atropine (IV)
Oximes (IV)
Diazepam (IV)
by complaints of pain, dim and/or blurred vision.
Miosis will begin within seconds or minutes after
the onset of exposure to agent vapor, but it may not
be complete for many minutes if the vapor concen-
tration is low. Very low levels of nerve agent can
cause these effects, as observed after the 1995
nerve agent attack on the subway system in Tokyo.
In that disaster a small number of health care
workers at the hospital exhibited these ocular signs
secondary to vapor release from patient clothing
[8,9]. In contrast, liquid agent exposure to the skin
will not cause miosis if the amount of liquid is
small unless it is in or near the eye. Only moderate
to large amounts of systemically absorbed nerve
agent will also result in miosis. Topical homat-
ropine or atropine in the eye can relieve the miosis,
pain, and dim vision.
Vapor exposure to nerve agent vapor also
increases secretions from exocrine glands, such as
the lacrimal, nasal, salivary, and bronchial glands.
Rhinorrhea is also an early indication of vapor
exposure to nerve agents. If sufficient vapor is
inhaled bronchoconstriction and increased airway
secretions will present in a dose-related manner.
Subjectively the patient may complain of chest
tightness and possibly trouble breathing. Apnea
can occur within minutes after the exposure to
a large amount of nerve agent and is primarily
centrally mediated though muscle weakness can
play a significant contributing role.
6.2.4.2 Gastrointestinal effects
After exposure to a large dose of nerve agent
there is an increase in gastrointestinal motility and
secretions along with nausea and vomiting. In the
absence of ocular and airway complaints these are
the earliest findings of systemic absorption after
liquid exposure on the skin. If the absorbed dose
in large enough diarrhea may occur with large
amounts.
