Gastric lavage means cleaning out the contents of the stomach. It is also called stomach pumping or Gastric irrigation. It is commonly done on a person who has ingested a poison or has taken an overdose of a drug. It should be done within 3 hours of ingestion of a poison. With poisons like salicylates , phenothiazines and tricyclic antidepressants, antihistaminics; lavage can be done upto 12 to 18 hrs after ingestion of poison.

Technique

•	Gastric lavage involves the passage of a tube via the mouth or nose down into the stomach, followed by sequential administration and removal of small volumes of liquid.
•	Patient should be lying on his left side or prone with head hanging over the edge of the bed and face down
•	The end of tube is lubricated before passing it by depressing the tongue.
•	The placement of the tube in the stomach must be confirmed either by air insufflation while listening to the stomach, by pH testing a small amount of aspirated stomach contents, or x-ray. This is to ensure the tube is not in the lungs.
•	In adults, small amounts of warm water or saline are administered and via a siphoning action removed again.
•	In children, normal saline is used, as children are more at risk of developing hyponatremia if lavaged with water.
•	Because of the possibility of vomiting, a suction device is always on hand in case of pulmonary aspiration of stomach contents.
•	Lavage is repeated until the returning fluid shows no further gastric contents. If the patient is unconscious or cannot protect their airway then the patient should be incubated before performing lavage.
•	Stomach is not completely emptied but a small quantity of the fluid containing the antidote or activated charcoal suspension is left behind in the stomach, so that it may neutralise the small quantity of poison that is left behind

Gastric lavage can be done with:

1.	1:5000 potassium permanganate
2.	5% sodium bicarbonate
3.	4% tannic acid
4.	1% sodium or potassium iodide
5.	1-3% calcium lactate
6.	Saturated lime water or starch solution
7.	0.9% saline

Indications
Gastric lavage should not be done routinely. Lavage should only be considered if the amount of poison ingested is potentially life-threatening.

Contraindications
Lavage is contraindicated when there is a risk of aspiration pneumonia or gastrointestinal hemorrhage or perforation. Relative contraindications include when the poisoning is due to a corrosive substance hydrocarbons.

Complications
The most dangerous risk is aspiration pneumonia, which is more likely to occur if hydrocarbons are ingested or in patients without a protected airway. Other complications include bradycardia, epistaxis, hyponatremia, hypochloremia, water intoxication, or mechanical injury to the stomach.