this presentation will help graduate and postgraduate level students for managing organo phosphates poisoning

5. Organophosphates are
used in suicidal cases
• Deliberate Use of OP :
• Accidental
OP :
taken in suicidal cases
• Accidentally taken by a child or adult
when they are kept in unknown
container

7. Mechanism of Action of OP

8. Clinical Manifestations
• The onset , severity and duration of Poisoning depend on the
route of exposure
And the agent used
• Triphasic illness follows OP intoxication :
• Acute cholinergic Crisis
• Intermediate syndrome ( IMS)
• OPIDN ( organophosphate –induced Delayed
polyneuropathy

9. Long – term occupational exposure to op pesticides
Nonspecific SMX
• H/A
• Nausea
• Fatigue
• Muscle twitching
• Visual disturbances
Chronic exposure to OP
Development of blood dyscrasias including aplastic anemia and
leukemia
Other Manifestation of chronic exposure :
• Anorexia
• Hepatotoxicity
• Renal toxicity
• CNS disturbances

10. Cholinergic Toxidrome

12. Various MNEMONICS have been used to describe the
Muscarinic signs of OPP
SLUDGE
• Salivation
• Lacrimation
• Urinary incontinence
• Diarrhea
• Gastrointestinal cramps
• Emesis
DUMBELS
• Diarrhea
• Urination
• Miosis
• Bronchospasm
Bronchorrhea
• Emesis
• Lacrimation
• Salivation

13. Intermediate syndrome
• Occurs 24 to 96 hrs. after ingestion of an OP compound
• Approx. 10-40 % of pts. treated for acute poisoning
develop this illness
• The onset of the IMS is often rapid , with progression of
muscle weakness From the
• Ocular muscles to neck
• Proximal limbs
• Respiratory muscles

14. Proposed Mechanism include :
• Persistent inhibition of ACHE - leading to functional paralysis of
NMT
• Muscle necrosis
• Oxidative free radical damage to the receptors

15. Organophosphate – induced delayed
polyneuropathy (OPIDN)
Occurs abt 1-3 wks. after acute exposure and uncertain period
following Chronic exposure , due to degeneration of long myelinated
nerve fibers
MECHANISM
Inhibition of neuropathy target esterase (NTE) enzyme in NT
by certain OP
i.e Chloropyriphos

16. Sign and symptoms
of OPIDN
• Cramping muscle pain
• Numbness and paraesthesia
• Acute limb weakness
• Muscle wasting & deformity such
as clawing of the hands
• Symmetrical flaccid weakness
• Tendon reflexes are reduced or
lost
• Later , mild pyramidal tract sign

17. Diagnosis :
• Hx of exposure to OP compound
• Characteristic manifestation of toxicity to OP
• Improvement of sign and smx after atropine administration
• Search of container of the poison in the vicinity of the pt by
asking the attaindents
• Garlic like smell – sulphur containing OP
Confirmatory investigations :
• CHE estimation (plasma Butyryl cholinesterase and Red cell ACHE )
useful biochemical
• Tool but poor guide to tx and px

18. Treatment
Acute Cholinergic Crisis
Decontamination and supportive
• Decontimation
• Supportive
• Blockade of Muscaric activity by ATROPINE
• Reversal of cholinesterase inhibition with OXIME
• Correction of metabolic abnormalities
• Protection of health care staff
• Maintain ABC
• Keep pt in lateral position if comatose or vomiting
• Frequent suction
• O2 therapy

19. DECONTAMINATION
• SKIN DECONTAMINATION
• GASTRIC LAVAGE
• ACTIVATED CHARCOAL
• AVOID INDUCED EMESIS

20. Presenting with in
2hrs of ingestion
Presenting after
2hrs of ingestion
Conscious Altered Conscious
Gastric Lavage
Activated
charcoal
Secure Airway
e.g. intubation
Gastric lavage
Activated Charcoal
Conscious
Altered
Conscious
OPP procedure of
decontamination
Activated
charcoal ?
Secure
Airway
ABC ?

21. ATROPINE :
• Specific Antidote - Muscaric no effect on Nicotinic smx
• Reverses life threatening features that can result in Death e.g
• Central Respiratory depression
• Bronchospasm
• Excessive Bronchosecretion
• Severe Bradycardia
• Hypotension

24. CURRENT GUIDELINES OF ATROPINE ADMINSTRATION :
• Bolus dose to attain target End points followed by setting up an infusion to
maintain these end points
Target End points for Atropine Rx
HR > 80 / min
Dilated pupils
Dry Axilla
Sys B.p > 80 mmHg
Clear chest on auscultation of Bronchorrhea

25. Recommended Dose of Atropine :
• Initial I/V bolus of 1.8 – 3mg with subsequent doses
• Dose is doubled every 5 mints until atropinization is achieved
Maintenance Dose :
• 20% of initial atropinizing dose /hr. for 1st 48hrs
• Gradually taper over 5-10 days . Continuously monitoring the
adequacy of RX

26. Atropine Toxicity
• Agitation
• Confusion
• Hyperthermia
• Urinary Retention
• Severe Tachycardia – ischemic events – CAD
• Close observation & dose adjustment is essential – to
avoid features of under and over atropinization
Anticholinergic Agent :
Glycopyrrolate along with atropine can be used in order to
limit the central stimulation produced by atropine

27. OXIMES :
Reactivating ACHE – that has been bound to the OP molecule
Pralidoxime : -
• Frequent used oximes worldwide
• Effective in restoring SM strength and improves diaphragmatic
weakness- where atropine has virtually no effect
Therapeutic window for Oxime
Limited – by the time taken for ageing of the enzyme – OP complex
because aged Enzyme can no longer be reactivated by oximes

28. WHO RECOMMENDATION OF OXIMES DOSE
• 30 mg / kg bolus IV followed by continuous infusion of 8mg/kg/hr
Infusion – continued until recovery :
Common S/E of OXIMES :
• Dizziness
• H/A
• Blurred vision
• Diplopia
Rapid Administration of OXIMES
• Tachycardia
• Laryngospasm
• Muscle spasm
• Transient NM blockade

29. Rx of IMS
• Ventilatory support
• Diazepam or Midazolam
• PTN
unless OPIDN develops recovery of IMS is
complete with adequate ventilatory care

30. Rx of OPIDN :-
• No specific Rx Measures
• Regular physiotherapy – reduce deformity caused by
muscle wasting
Recovery from OPIDN :-
• incomplete
• May be limited to hands and feet
Although substantial functional recovery after 1-2 yr. may
occur in younger pts.

31. Summary

32. Home Message
• OP are dangerous chemicals
• OP can be misused by antisocial elements .
• It should be remembered OP may be used in future wars and that
war will be the war of Nerves .
• Immediate management of a pt.
• Treatment must not be delayed .
• Proper observation of treatment .