The average diameter of capillaries in the human body is only 7 μm to 9 μm, and the smallest is 4 μm. If the fluid is infused frequently, particles larger than 4 μm in diameter will accumulate in the capillaries of the heart, liver, lungs, brain, kidneys, muscles, and skin. Larger particles can directly cause capillary embolism, causing local insufficiency, tissue hypoxia and edema and inflammation. Smaller particles may be swallowed by macrophages, causing macrophages to enlarge and form granuloma. These changes can occur in whole body tissues, especially the lungs. In addition, the microparticles can also directly cause an exothermic reaction. At present, during the infusion process, infusion reactions occur frequently. In addition to bacterial contamination reactions and pyrogenic reactions, particulate contamination reactions caused by insoluble particles are also receiving increasing attention. The use of precision filtration infusion sets is an effective measure to reduce infusion reactions, because the infusion set's liquid filter is the last way to filter out particles in the drug solution. Experts found through experiments that no infusion reaction occurred when using a one-time precision infusion set, and that 15 infusion reactions occurred when using a common infusion set.
