Organophosphate poisioning in pediatric age group

OP poisioning in children

1. ORGANOPHOSHATE POISONING

2. ORGANOPHOSPHATE POISONING Organophosphates and carbamates are commonly used pesticide agents and a common cause of poisoning in developing nations . Organophosphates cause toxicity by inactivating acetylcholinesterase , resulting in excess of nicotinic and muscarinic activity in the peripheral and central nervous systems . These agents form an irreversible bond with and permanently inactivate the enzyme. On the other hand, carbamates reversibly bind with the enzymes

3. Clinical features The symptoms of organophosphate toxicity depend upon the route, duration of exposure, and the absorbed dose. Acute poisoning is characterized by three phases: Cholinergic crisis intermediate syndrome delayed neuropathy

4. The features of acute cholinergic crisis include diarrhea , urination, miosis , bronchorrhea /bronchospasm, bradycardia , emesis, lacrimation and salivation ( DUMBBELS ). Some patients show nicotinic features with hypertension , tachycardia and dysrhythmia, muscle weakness , fasciculations , tremors and hypoventilation. Patients with severe poisoning may present with coma and respiratory failure which may rapidly progress. While recovering from cholinergic crisis, some patients may suddenly develop respiratory failure (intermediate syndrome). Late complications of poisoning include delayed polyneuropathy and a range of chronic neuro -psychiatric symptoms .

5. LABORATORY MANIFESTATION The diagnosis of organophosphate poisoning is based on characteristic clinical signs , smell of the organophosphate compounds , and reduced butyrylcholinesterase in plasma or acetylcholinesterase activity in blood . The major differential diagnosis is carbamate poisoning, which is clinically indistinguishable. Cholinesterase assays : There are two types of choline- sterases , acetylcholinesterase and butyrylcholinesterase ; values <10% normal of either of the enzymes indicates severe poisoning. Emergency treatment should not be delayed while awaiting results of the enzyme assays.

6. TREATMENT