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

2. Organophosphorus
poisoning
PREPARED BY:
RN Arpana Bhusal
BNS

3. Contents
 Introduction
 Causes
 Sign and symptoms
 Treatment
 Prevention
 References

4. Introduction
 Organophosphate
poisoning is poisoning due
to organophosphates (OPs). Organop
hosphates 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

5.  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

6. 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.

7. SYMPTOMS

8. 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

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

10. 3 CNS effects:
• Restlessness, insomnia, tremors and
confusion.
• Convulsions and coma.
• Depression of respiratory and
cardiovascular system.
 Death is usually due to respiratory
failure

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

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

14. 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

15.  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

16.  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.

17.  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

18.  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.

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

20.  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.

21.  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

22.  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

23.  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

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

25. 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.

26. References
 (http://www.who.int/hiv/pub/imai/en/ac
utecarerev2_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