The purpose of sodium heparin sealant injection is to keep the tubing of intravenous injection devices, such as indwelling needles and catheters, open to prevent the formation of blood clots. A sufficient dose of sodium heparin injection should be injected into the injection device to fill the device, and the injection should be replaced with a new one before each use. Before administering the drug through the device, check for the presence of blood flow back to confirm that the tubing is open and properly positioned. If the drug used is contraindicated with sodium heparin, the device should be flushed with saline before and after administration, and after the second flush, the sodium heparin should be injected into the lumen to seal the tube. The product instructions should be read in detail before use. In general, sodium heparin can maintain its anticoagulant effect in the device for more than four hours.