The purpose of intravenous infusion is to replenish water and electrolytes, enter drugs, and replenish blood volume. The precautions for intravenous infusion are three checks and seven checks, aseptic operation, prevention of air embolism and so on. 1. The purpose of intravenous infusion: (1) replenish water and electrolytes: the purpose of intravenous infusion needs to correct water and electrolyte disorders and maintain acid-base balance, commonly used in patients with dehydration and acid-base balance imbalance caused by various reasons. (2) Input of drugs: The purpose of intravenous infusion is also to input drugs to achieve the purpose of controlling infection and treating diseases, commonly used in patients with various kinds of poisoning and serious infections. (3) Supplementing blood volume: intravenous infusion can improve microcirculation and maintain blood pressure, which is often used to rescue patients with severe burns, hemorrhage and shock. 2. Precautions for intravenous infusion: (1) Three-checking and seven-checking: It is very important to strictly implement the system of three-checking and seven-checking for intravenous infusion to prevent the occurrence of accidents of wrong injection and wrong medicine. (2) Aseptic operation: the infusion set and liquid should be absolutely sterile during intravenous infusion, and the infusion set needs to be replaced if the patient is continuously infused for more than 24 hours. (3) Prevention of air embolism: Before intravenous infusion, the air inside the body must be drained, the infusion bottle must be replaced and the liquid added in time, the needle must be removed in time after the infusion, and the patient must be observed for half an hour to see if there is any reaction to the infusion. In the process of infusion, must pay attention to the patient’s condition changes. If there are any uncomfortable symptoms, you should ask the doctor in time to avoid bringing harm to the patient.