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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