Tachyphylaxis excretes potassium ions along with urine. When the concentration of potassium ions in the blood is lower than normal, the child often shows weakness in the limbs and is prone to arrhythmia. To replenish the large loss of potassium ions, potassium chloride must be taken at the same time as tachyphylaxis, and the supply of potassium ions can also be increased through food. Common foods and fruits rich in potassium ions include: spinach, bitter melon, papaya, lemon juice, banana, grapefruit, orange, tangerine, watermelon, strawberry, etc. The duration of taking tachyphylaxis depends on the condition, and the dosage should be adjusted or discontinued on the advice of the doctor. If the child has a large postoperative heart, swollen face and face (especially both eyelids), dorsal foot, little urine and fast heart rate, suggesting cardiac insufficiency, he needs to take diuretics and other drugs. In children with complex and severe precordial disease, diuretics are taken for a longer period of time after surgery, usually 3-6 months, or even longer in some cases.