Organophosphate poisoning

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Organophosphate poisoning

  1. 1. ORGANOPHOSPHATE POISONING NOOR HAFIZAH BINTI HASSAN 2007287236
  2. 2. REFERENCES <ul><li>Early management after self-poisoning with an organophosphorus or carbamate pesticides-a treatment protocol for junior doctors. Michael Eddleston, Andrew Dawson, Lakshman Karalliedde, Wasantha Dissanayake, Ariyasena Hittarage, Shifa Azher and Nick A Buckley. Critical Care 2004, 8:R391-R397 </li></ul><ul><li>Common Mechanism of Toxicity: A Case Study of Organophosphorus Pesticides. Mileson, B. E., Chambers, J. E., Chen, W. L., Dettbarn, W., Enrich, M., Eldefrawi, A. T., Gaylor, D. W.,Hamernik, K., Hodgson, E., Karczmar, A. G., Padilla, S., Pope,C. N., Richardson, R. J., Saunders, D. R., Sheets, L. P., Sultatos,L. G., and Wallace, K. B. (1998). Toxicol. Sci. 41, 8-20. </li></ul>
  3. 3. INTRODUCTION <ul><li>Organophosphate  widely used in agricultural sector as PESTICIDES. </li></ul><ul><li>Nerve agents  sarin, tabun, soman, VX, VE </li></ul><ul><li>Mortality a/w self-poisoning with pesticides: </li></ul><ul><ul><li>50-70 % in developing world </li></ul></ul><ul><ul><li>0.3 % in developed world </li></ul></ul><ul><li>Malaysia  2 nd after paraquat poisoning (Sirajuddin, 2002). </li></ul>
  4. 4. Distribution of Poisoning Cases by Types of Poison from 2001-2005
  5. 5. PHYSIOLOGY REVISITED
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  8. 8. MECHANISM OF ACTION OF ORGANOPHOSPATE POISONING COVALENT BOND AGING
  9. 9. MECHANISM OF ACTION OF ORGANOPHOSPATE POISONING <ul><li>Irreversibly bind to serine-OH group at the active site of acetylcholinesterase (AChE)  establish covalent bond ( phosphorylation) </li></ul><ul><li>↓ </li></ul><ul><li>AGING: loss of alkyl group + strengthening of covalent bond </li></ul><ul><li>↓ </li></ul><ul><li>Phosphorylated AChE is very stable </li></ul><ul><li>↓ </li></ul><ul><li>Inhibition of enzyme activity  accumulation of ACh in the synapse and NMJ </li></ul><ul><li>↓ </li></ul><ul><li>Overstimulation of cholinergic receptors </li></ul>
  10. 10. CLINICAL PRESENTATION <ul><li>MUSCARINIC: SLUDGE </li></ul><ul><li>S -Salivation </li></ul><ul><li>L -Lacrimation </li></ul><ul><li>U -Urination </li></ul><ul><li>D -Diarrhoea </li></ul><ul><li>G -GI upset </li></ul><ul><li>E -Emesis </li></ul><ul><li>NICOTINIC: MATCH </li></ul><ul><li>M -Muscle weakness and fasciculation </li></ul><ul><li>A -Adrenal medulla activity ↑ </li></ul><ul><li>T -Tachycardia </li></ul><ul><li>C -Cramping of skeletal muscle </li></ul><ul><li>H -Hypertension </li></ul>
  11. 11. PRINCIPLE OF MANAGEMENT <ul><li>History taking: What, When, How much, Why </li></ul><ul><li>1° survey: protect yourself + decontaminate </li></ul><ul><li>Initial assessment: A B C D E </li></ul><ul><li>Recognition of organophosphate poisoning </li></ul><ul><ul><li>MIOSIS </li></ul></ul><ul><ul><li>DIAPHORESIS </li></ul></ul><ul><ul><li>↓ /POOR AIR ENTRY </li></ul></ul><ul><ul><li>BRADYCARDIA </li></ul></ul><ul><ul><li>HYPOTENSION </li></ul></ul>
  12. 12. <ul><li>Antidote: Atropine & Pralidoxime </li></ul><ul><li>IV fluid </li></ul><ul><li>Confirmation of exposure to cholinergic compounds </li></ul><ul><ul><li>Measure butyryl cholinesterase or red cell AChE activity </li></ul></ul>LOADING DOSE: IV 0.5-2 mg over 5-10 min until atropinization achieved MAINTENANCE DOSE: (8 mg mix in 100 mL normal saline) at a rate of 0.02-0.08 mg/kg/hr <ul><li>effective within 24 hours of exposure </li></ul><ul><li>1-2 g IV in 100 mL normal saline within 30min. </li></ul><ul><li>repeat if muscle weakness did not relieve in 1 hour </li></ul>
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  14. 14. CASE: <ul><li>14 y/o Indian girl </li></ul><ul><li>Brought to resus HSB on 8 th Feb 2009 at 1050 by family after mom noted a strange smell </li></ul><ul><li>Took insecticides from the back of her house at around 0900 </li></ul><ul><li>Minimal amount (< 1/3 of the bottle content) </li></ul><ul><li>No suicidal note </li></ul><ul><li>Claimed that she was stressed  friends keep commenting on the PIMPLES on her face. </li></ul>
  15. 15. ASSESSMENT <ul><li>On arrival: alert and conscious </li></ul><ul><li>Vital signs: </li></ul><ul><ul><li>Heart rate: 132 beats/min </li></ul></ul><ul><ul><li>Blood pressure: 143/90 mmHg </li></ul></ul><ul><ul><li>O 2 saturation: 89% on room air </li></ul></ul><ul><ul><li>Pulse rate: 21 breaths/min </li></ul></ul><ul><ul><li>Temperature: 37°C </li></ul></ul><ul><li>Vomiting </li></ul><ul><li>Throat & abdominal discomfort </li></ul><ul><li>No chest pain / SOB </li></ul><ul><li>Pupils 2mm constricted </li></ul><ul><li>Sweaty peripheries </li></ul><ul><li>Lungs: transmitted sound </li></ul><ul><li>PA: soft, non tender </li></ul>
  16. 16. MANAGEMENT <ul><li>2 large bore IV needle </li></ul><ul><li>High flow mask 15L/min </li></ul><ul><li>IVD Normal Saline </li></ul><ul><li>Clean-sponging & change clothes </li></ul><ul><li>Close monitoring of vital signs </li></ul><ul><li>Gastric lavage & Ryle’s tube inserted </li></ul><ul><li>Activated charcoal 50mg </li></ul><ul><li>IV Atropine 0.25 mg every 2min until atropinization achieved </li></ul><ul><li>IV ranitidine </li></ul><ul><li>Suicidal precaution </li></ul><ul><li>Blood ix: FBC; RP; LFT; amylase; PCM, salicylate, benzodiazepine level; CXR, urine paraquat </li></ul>
  17. 17. <ul><li>Thank </li></ul><ul><li>you </li></ul>

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