Poisoning is to injure or kill with a substance that through its chemical action kills, injures or impairs an organism. It may be accidental, unintentional or intentional.

The history of poisons dates to antiquity. Its description is known as early as 1600 B.C. It was the province of the ancient sorcerers, magicians, witches and priests and poison was supposed to harm only the guilty people. Socrates was reported to have been killed by poisoning by those who did not like his progressive thinking. In the 13th century, Peter of Abanos divided the poisons into 3 groups- from vegetable origin, from animals and minerals. Gradually more and more poisons were known and their indexing has now been done. As drugs were discovered, their accidental ingestion by the smaller children also followed. Newer antidotes were discovered, toxic screens found and information dissemination programmes were developed. Poisoning cases form 2-4 % of the admissions in the PICU. These include household poisons like kerosene, organophosphorus compounds, detergents, baby powder etc. Also drugs for chronic therapy like antiepileptics, iron tablets, antihistamines etc because of their easy accessibility are accidentally consumed by the toddlers especially if left around without protection. Poisoning by snakes, scorpions are also seen.

COMMON POISONS
 

>>	Kerosene
>>	Insecticides and pesticides.
>>	Snake bites
>>	Scorpions stings
>>	Barbituates
>>	Phenytoin
>>	Diazepam and other sedatives.
>>	Paracetamol
>>	Iron
>>	Vitamins
>>	Digoxin
>>	Lead.

CLINICAL FEATURES
 
The symptoms due to the consumed poison vary in the time of onset, types of presentation, and the severity. The dose of the poison consumed is also important. Most of the poisons have a cardiovascular or central nervous system action.

Examples- CNS- Coma with sedatives, barbiturates, tranquilizers. Seizures occur with CO, anticholinergics, lead, lithium, theophylline.

CVS- CO, quinine, digoxin, tricyclic antidepressants, ethanol, arsenic can lead to arrhythmia.
GIT- Iron, mercury, lithium, phosphorus, arsenic, theophylline, organophosphorus, paracetamol(liver).
Renal- Mercury, ethylene glycol, carbon tetrachloride.
Metabolic acidosis- Salicylates, ethanol, toluene.
RS- Kerosene.
Hematology- Snake bite.
Metabolic- Hydrofluoric acid (Ca)

DIAGNOSIS

The history of poisoning may be either straightforward or suspected. The suspicion needs to be kept in mind if there is multisystem involvement of unknown cause. Appropriate tests need to be carried out in such cases.

FIRST AID
 

>>	The patient should be reassured.
>>	The victim should be shifted away from the area of poison.
>>	Eliminate the poison from the eyes and the skin by proper irrigation. Copious amount of water should be used.
>>	Induce vomiting with concentrated salt solution, emetics or throat stimulation. If unconscious or patient is tired do gastric lavage. This is not advocated with acids, alkalis, and kerosene. The reason being that with kerosene there are chances of aspiration and pneumonitis. The esophageal wall may rupture with the ryles tube in case of the acids and alkalis poisoning.
>>	Activated charcoal may be given for adsorption of the toxins. If it is unavailable, burnt toast serves the purpose. The dose of activated charcoal is 1 g/kg in 4 ounces of water. The activated charcoal may not be effective in heavy metals, iron, organophosphorus, acids, alkalis and alcohol poisonings. The activated charcoal to drug ratio should be 10:1.It is a universal general antidote. Local milk, bananas, demulcents, neutralizers can also be used. Catharsis is needed for rapid exit and decreased absorption. Magnesium sulphate is useful in this.
>>	Inform the police.
>>	The victim if conscious can be given bananas, milk and the like to decrease the local action of the poison and to aid its elimination.
>>	Preserve ant suspicious bottle or container.
>>	Collect the vomitus for chemical analysis.
>>	Give cardio-respiratory resuscitation if there is difficulty in breathing or there is heart beat problem.