Gastric lavage is generally applied within 1 hour of oral poisoning, and for those who take slowly absorbed poison and whose gastrointestinal peristaltic function is weakened or disappeared, gastric lavage can also be given within 4-6 hours after taking poison, because gastric lavage is a more important method to expel poison, but gastric lavage also has certain indications and contraindications. I. Indications 1. For non-corrosive poisons, various oral drugs, food poisoning, such as organophosphorus pesticide poisoning, sleeping pills, heavy metal and alkaloid poisoning, etc., gastric lavage can be used to reduce the absorption of toxic substances in the stomach and alleviate the symptoms of poisoning in patients; 2. Gastric lavage can also be used when needed for surgery and examination, such as pyloric obstruction, obvious gastric retention, gastric dilatation, if gastrointestinal surgery or examination of the stomach is required. Gastric lavage is also applicable to these patients when gastrointestinal surgery or examination of the stomach is required. Second, contraindications 1, if the patient has acute upper gastrointestinal bleeding, gastric perforation, esophagogastric fundic vein rupture varices, gastric lavage is prohibited, because gastric lavage will lead to increased bleeding of gastric mucosal damage, or even the risk of gastric rupture; 2, if the patient is taking strong acid, strong alkali drugs, gastric lavage should also be prohibited, because either emetic gastric lavage or mechanical gastric lavage may cause corrosive gastric perforation, etc. 3, deep coma, patients whose cardiopulmonary resuscitation is still in progress, and patients with severe cardiorespiratory underlying disease are also prohibited from gastric lavage. Because gastric lavage may cause aspiration pneumonia and aggravate heart failure; 4, if the stomach in the short term for some surgery, such as gastroduodenal repair, major gastrectomy, gastroenterostomy, etc., also prohibit gastric lavage to prevent the emergence of postoperative wound recurrence; 5, gasoline, kerosene poisoning, etc., easy to dry vomiting, reflux aspiration of the trachea, causing pneumonia. In the process of gastric lavage, if the patient suddenly has convulsions, gastric lavage should be stopped immediately and rapid-acting sedatives should be used to stop the convulsions; if respiratory arrest occurs, the gastric tube should be removed immediately, artificial respiration should be done, and tracheal intubation should be performed while oxygen is given.