The purpose of flushing is to keep the tubing open to prevent obstruction of the tubing due to blood, food residue or foreign bodies in the abdominal cavity. For example, during infusion, an intravenous needle is placed in the arm, and the tube needs to be flushed with saline before the needle is used to prevent blood from coagulating inside the needle and affecting the intravenous input. Gastric tubes and enteral nutrition tubes in the gastrointestinal tract also need to be flushed before use, and sometimes enteral nutrition fluid forms clots inside the tubes, causing them to become inaccessible. When the abdominal drainage tube has been in use for a long time, there will be necrotic tissue inside the abdominal cavity, resulting in blockage of the drainage tube and poor drainage, so it is necessary to flush the tube with saline when necessary.