Op poisoning

Organophosphate poisoning is poisoning due to organophosphates (OPs). Organophosphates are used as insecticides, medications, and nerve agents.
Symptoms include increased saliva and tear production, diarrhea, vomiting, small pupils, sweating, muscle tremors, and confusion.
Other names: Organophosphate toxicity
Causes:  organophosphates

1. Organophosphorus poisoning PREPARED BY: RN Arpana Bhusal BNS

2. Contents Introduction Causes Sign and symptoms Treatment Prevention R eferences

3. Introduction Organophosphate poisoning  is  poisoning  due to  organophosphates  (OPs).  Organophosphates  are used as insecticides, medications, and nerve agents. Symptoms include increased saliva and tear production, diarrhea, vomiting, small pupils, sweating, muscle tremors, and confusion. Other names:  Organophosphate toxicity Causes:  organophosphates

4. Organophosphates are phosphate esters that irreversiblely inhibit AChE • These are highly toxic • These chemicals are nerve poisions and have been used in warfare, in bioterrorism, and as agricultural insecticides

5. Causes 1 . Inhalation of sprays or dusts of insecticides. 2. Contamination of skin of agricultural workers. 3. Contamination of crops or food. 4. Accidental or intentional ingestion of insecticides. 5. War gases in the chemical war.

6. SYMPTOMS

7. Symptoms 1 . Muscarinic effects: • Bradycardia and hypotension. • Bronchoconstriction and increased bronchial secretion. • Excessive sweating, salivation and lacrimation. • Miosis . ( • Nausea, vomiting, abdominal cramps and diarrhea. • Urinary incontinence

8. 2. Nicotinic effect: • Muscle twitches followed by weakness. • Neuromuscular blockade of diaphragm and the intercostal muscles

9. 3 CNS effects: • Restlessness, insomnia, tremors and confusion. • Convulsions and coma. • Depression of respiratory and cardiovascular system. Death is usually due to respiratory failure

10. Investigation • Routine bloods, • ECG and • chest x-ray • Markedly depressed serum cholinesterase activity below normal range

11. Altered arterial blood gases (acidosis), serum electrolytes, and serum creatinine in response to respiratory distress and shock within 1 to 6 hours

12. Management 1. Ensure adequate airways protection –If the patient has respiratory distress intubate early (avoid succinylcholine!) 2. Ensure adequate oxygenation – give high flow oxygen via a face mask. 3. Ensure adequate circulation – insert cannula and give iv fluids

13. Give atropine until patient is fully atropinised . Start with 0.05mg/Kg of atropine iv (2-4mg depending on patient weight ). -Repeat every 15 mins until full atropinisation . -Aim for pulse rate >80 beats per minute and systolic blood pressure >80mm/Hg. Increase atropine bolus dose until response occurs

14. 5. Start atropine infusion when atropinisation achieved – 0.05mg/kg/hour . -E.g. for a 70kg patient give 3.5 mg of atropine per hour as an infusion.

15. 6. Monitor patient ever 15 minutes. - If the dose of atropine is too low cholinergic features will re occur. - If the dose of atropine is too high agitation, pyrexia, reduced bowel sounds and urinary retention will occur – then reduce atropine infusion

16. 7. If patient presents within 24 hours of exposure and has signs of moderate to severe organophosphate poisoning give pralidoxime (PAM)250mg iv. – repeat after 2 hours. - Note give parlidoxime after initial atropine bolus.

17. Perform a 12 lead ECG – treat arrhythmias as necessary , intravenous magnesium maybe helpful

18. 9. Monitor patient for secretions, pulse rate ( use cardiac monitor), pupil size, blood pressure, oxygen saturation and pulse. - The aim of treatment is to excessive oral and respiratory secretions and prevent respiratory failure . - Adequate atropinisation is indicated by reduction of secretions .

19. 10. Control fits with boluses of diazepam – give10mg ivi . Diazepam is also useful for delirium and agitation in these patients. -Note agitation may be due to excess atropine

20. 11. There is no evidence to support the use of activated charcoal or gastric lavage. 12 . Remove contaminated clothing (wear gloves) and dispose of as hazardous material. - Wash the Patient thoroughly with soap and water

21. 13 . As soon as patient is stable start to reduce atropine infusion slowly over 24 hours. -Infusion may need to be increased if symptoms and signs recur

22. Patients with minor exposure to organophosphates can be discharged if asymptomatic after 12 hours of observation.

23. Prevention Protective gear should include covering the head and neck, wearing a mask or respirator, and using eye protection . Any exposure to organophosphates should be washed off immediately with water and a mild alkaline soap . Avoid the use of detergents, as they may increase absorption by removing the skin's protective oil.

24. References ( http://www.who.int/hiv/pub/imai/en/acutecarerev2_e.pdf, @2021/7/09 at 3pm . https:// www.Mayoclinic.org/disease-conditions/op-poisoning/diagnosis-treatment/drc-20356236 @ 2021/7/8 at 6pm. January 17, 2013.op poisoning . https://www.slideshare.net@2021/07/07 at 2pm . www.medicostuff.com