Poison: Any substance taken into the body by any means in sufficient quantity that interferes with the normal physiological function is called poison.
Poisoning: It is a harmful effect of poison.
Causes/Types of poison
1. Accidental Poison
Poison took in an unknown way. For example Kerosene oil drinking by children, Organophosphorus poisoning during using pesticides on farms, Arsenic poisoning, etc.
2. Suicidal Poisoning
Poison took by self with the intention of suicide. For example Organophosphorus poisoning, Barbiturates, etc.
3. Homicidal Poisoning
The poison is used to kill or harm others for purpose of quarrel. For example Dhatura, Zinc phosphide, etc.
Points to be noted in case of poisoning
- Time of poisoning
- Type of poisoning
- Amount of poisoning
- Patient brought by
- Cause of poisoning
- Inform to the police
The general principle of management of poisoning
- Remove the patient from the source of exposure.
- Support and maintain vital signs by ABC management
- A – Airway- Clean the airway with gauze or suction to prevent aspiration
- B – Breathing- Mouth to mouth or Oxygen supply or Ambu bag ventilation as per the requirement of the patient.
- C – Circulation- IV assessment or Cardiopulmonary Resuscitation
- Decontamination
- Wash the contact area of the eye, and skin with water or normal saline.
- Remove contaminated clothes of the patient.
- Gastric lavage within 2 hours of poison ingestion.
- Enhancement of elimination
- Use of specific antidote.
Common poison
- Organophosphorus poison (Most common)
- Zinc phosphide poison
- Aluminium phosphide poison (highly Toxic)
- Alcohol Intoxication
- Benzodiazepine poison
- Dhatura poison
Organophosphorus(OP) poison
Common OP compounds
A. Dimethyl compounds
- Dichlorous
- Fenthion
- Malathion
B. Diethyl compounds
- Chlorpyrifos
- Parathion
- Diazinon
- Quinalphos
Mechanism of Organophosphorus poison in the human body
Clinical features of OP Poisoning
A. Acute cholinergic features: Seen within minutes
I. Muscurinic effect
- Diarrhoea
- Urination
- Miosis – Constriction of the pupil (pin pupil)
- Bradycardia
- Bronchorrhea
- Broncho constriction
- Lacrimation
- Emesis
- Salivation
II. Nicotonic effect
- Muscle cramps
- Muscle weakness
- Hypertension and tachycardia
- Paralysis
III. CNS Effect
- Headache
- Dizziness
- Fine tremors
- Confusion
- Coma
B. Intermediate syndrome: occurs in 48 hours
C. Organophosphorus Inducted Delayed Polyneuropathy: Occurs after 1-3 weeks
Investigation for Organophosphorus Poisoning
- Blood test – Complete Blood Count (CBC), Serum Level of Sodium(Na), Potassium(K), Calcium(Ca), etc
- Chest x-ray: Posterior- Anterior View
Treatment of Organophosphorus Poisoning
A. General Measures
- Maintenance of airway, breathing and circulation.
- Remove clothing, and wash skin with soap and water if direct contact to the skin.
- Gastric lavage in case of ingestion within 2 hours is done by potassium permanganate or activated charcoal.
- Catheterization. Keep nothing per oral/ Nill per oral (NPO)
B. Specific measures
1. Atropine (Anticholinergic drugs)
Loading dose: 1 to 2 mg every 10 minutes till the patient is atropine.
Maintenance dose: 20% of the total amount of atropine required for maintenance per hour for 2-3 days.
2. Pralidoxime:
1 to 2 gram IV bolus over 30 minutes then 500mg every 6 to 8 hours for 2-3 days.
3. Supportive measures:
- If convulsion – IV diazepam
- If respiratory failure – Oxygen supply / Ventilation
- OPIDN – Regular physiotherapy
Atropine sensitivity test
This test is done on the patient to find out whether atropine is sensitive to the patient or not. 2-3mg atropine IV bolus is given and the maximum heart rate is recorded. If there is a raise in heart rate >25 beats per minute from the baseline, the patient doesn’t need atropinization.
Sign of atropinization
- Secretion controlled
- Skin and tongue dry
- Sinus tachycardia(Heart rate >120 b/m)
- Normal pupil size
Different poisons and their antidotes
| Universal Antidote | Activated Charcoal |
| Organophosphorus | Atropine |
| Cyanide | Amyl nitrate |
| Mushroom Poisoning | Atropine |
| Atropine / Dhatura | Physostigmine |
| Opioids | Naloxone |
| Heparin | Protamine sulphate |
| Acute iron overdose | Desferrioxamine |
| Acetaminophen | N-acetyl cystine |
| Diazepam | Flumazenil |
| Beta-blocker | Glucagon |
| Methanol | Ethanol |
The technique of gastric lavage
- Insertion of Nasogastric tube (NG Tube) into the stomach.
- Confirm that the tube is in stomach.
- If the patient is able to drink give him/her activated charcoal or potassium permanganate mixed in 5-6 litre of water.
- If not able to drink give activated charcoal or potassium permanganate mixed with NS via NG tube.
- Then use 2 litres of plain water or NS.
