Post on 08-Jul-2015
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ACUTE RADIATION CNS SYNDROME & NEUROLOGICAL DAMAGE CAUSED BY CHEMICAL AGENTS
Deepak AgrawalAssistant Professor, Neurosurgery,JPNATC, AIIMS, N Delhi
ARS- Definition
An acute illness caused by irradiation of the entire body (or most of the body) by a high dose of penetrating radiation in a very short period of time
PREREQUISITES
The radiation dose must be large The dose usually must be external The radiation must be penetrating The entire body The dose must have been delivered in a
short time
ARS Syndromes
Central Nervous System (CNS) syndrome
Bone marrow syndrome Gastrointestinal (GI) syndrome
Central Nervous System (CNS) syndrome
dose greater than approximately 50 Gy (5000 rads)
Death occurs within 3 days.
Four stages of ARS
Prodromal stage (N-V-D stage) Latent stage Manifest illness stage Recovery or death
Patient Management
Triage Secure ABCs Treat major trauma, burns and respiratory injury Obtain blood samples for CBC (complete blood
count), lymphocyte count, and HLA Treat contamination repeat CBC approximately every 2 to 3 hours
Management
Andrews Lymphocyte Nomogram
Management
Treat vomiting and repeat CBC analysis
Record all clinical symptoms
Management
supportive care in a clean environment (prevention and treatment of infections)
stimulation of hematopoiesis by use of growth factors
stem cell transfusions or platelet transfusions (if platelet count is too low)
psychological support
Management
careful observation for erythema (document locations), hair loss, skin injury, mucositis, parotitis, weight loss, or fever
confirmation of initial dose estimate using chromosome aberration cytogenetic bioassay when possible.
consultation with experts in radiation accident management
NEUROLOGICAL DAMAGE CAUSED BY CHEMICAL
AGENTS
Organophosphate colourless, odourless gas with a lethal
dose of just 0.5mg for an adult human (or 0.01mg/kg of body weight).
Competitive inhibition of the enzyme acetyl cholinesterase
SARIN
SARIN
ROUTES OF EXPOSURE Inhalation skin contact eye contact Ingestion is an uncommon route of
exposure.
SARIN
SYMPTOMS Diarrhea, diaphoresis Urination Miosis Bradycardia, bronchospasm, Vomiting Lacrimation, salivation Weakness, Paralysis
Sarin
INDICATIVE LAB TESTS Decreased cholinesterase Increased anion gap Metabolic acidosis
DECONTAMINATION
The hydrolysis reaction is rapid and used for the decontamination of affected areas:
Solids, powders and solutions containing various types of bleach ( NaOCl- or Ca(OCl-)2 )
DECONTAMINATION
DS2 ( 2% NaOH, 70% diethylenetriamine, 28% ethylene glycol monomethyl ether )
Towlettes moistened with NaOH dissolved in water, phenol, ethanol and ammonia
TREATMENT
Triage Secure ABCs Antidote Diazepam (5 to 10 mg in adults and 0.2 to
0.5 mg/kg in children) may be used to control convulsions.
ANTIDOTE
Atropine and pralidoxime chloride (2-PAM Cl) are antidotes for nerve agent toxicity
2-PAM Cl (25mg/Kg i/m) must be administered within minutes to a few hours (depending on the agent) following exposure to be effective.
Atropine (2-4mg i/m) should be administered every 5 to 10 minutes until secretions begin to dry up.
SARIN
DELAYED EFFECTS OF EXPOSURE: Patients/victims who have severe exposure should be evaluated for persistent central nervous system (CNS) effects.
EFFECTS OF CHRONIC OR REPEATED EXPOSURE
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