Principle of potassium supplement: 1) oral potassium supplement: oral potassium supplement is the safest way to supplement potassium, such as 10% potassium chloride or potassium citrate; 2) Intravenous potassium supplementation: it cannot be taken orally, but it can be administered intravenously. The commonly used injection is 10% potassium chloride. Intravenous potassium supplementation must pay attention to the following points: 1 "potassium supplementation after urine": generally, potassium can only be supplemented when the urine volume exceeds 40ml/d or 500ml/d; The amount of potassium supplement depends on the serum potassium level. If only on an empty stomach, generally give 2 ~ 3 grams of potassium chloride every day; The total amount of potassium supplement for patients with severe potassium deficiency (serum potassium > 2 < 2 mmol/L) should not exceed 6 ~ 8g per day, except for severe diarrhea, acute renal failure and polyuria. (3) The concentration of potassium supplement: it shall not exceed 40mmol/L (3 g/L of potassium chloride); Intravenous drip should be given after dilution, and direct intravenous injection is prohibited to avoid sudden increase of blood potassium and cardiac arrest. (4) Potassium supplement speed: it should not exceed 20 ~ 40 mmol/h ... The adult intravenous drip speed should not exceed 80 drops/minute.