2. INTRODUCTION
Organophosphate (OP) compounds
are a diverse group of chemicals
used in both domestic and
industrial settings. Examples of
organophosphates include
insecticides (malathion, parathion,
diazinon, fenthion, dichlorvos,
chlorpyrifos, ethion), nerve gases
(soman, tabun, VX), ophthalmic
agents (echothiophate,
isoflurophate), and antihelmintics
(trichlorfon). Herbicides (tribufos
[DEF], merphos) are tricresyl
phosphate–containing industrial
chemicals.
5. PATHOPHYSIOLOGY
Once an organophosphate binds to AChE, the
enzyme can undergo one of the following:
• Endogenous hydrolysis of the phosphorylated enzyme
by esterases or paraoxonases
• Reactivation by a strong nucleophile such as
pralidoxime (2-PAM)
• Irreversible binding and permanent enzyme inactivation
(aging)
1. The poison is inhaled
2. OP compound inhibits the
ACHE action.
3. Accumulation of Ach.
which activates the
muscarinic and nicotinic
receptors.
8. Rx…
•The mainstays of medical therapy in organophosphate (OP) poisoning include
atropine, pralidoxime (2-PAM), and benzodiazepines (eg, diazepam)
•And other supportive therapies
9. Management
Management of organophosphate poisoning
1. check airway, breathing, circulation.
2. monitor arterial oxygen saturation, cardiac rhythms, BP,
Pulse rate.
3. look for signs & symptoms.
4. obtain IV access.
5. remove the contaminated clothes&wash the skin
thoroughly with soap & water
6. give atropine intravenously as soon as possible for
symptomatic patient
7. perform gastric decontamination with gastric lavage once
the patient is stabilised & within two hours of ingestion.
8. give activated charcoal (50 g in 200 ml)
9. maintainance atropine infusion
10. give pralidoxime .