1. Energy: The total daily energy of intravenous nutrition for adults is 25-35 kcal/kg, and the total energy required for 70 kg patients is 1750-2450 kcal. Glucose is often used to provide energy, producing 4 grams of carbon dioxide per kilocalorie of glucose, so the daily glucose is between 420 and 590 grams.

2. protein: The daily protein requirement of adults is 1.2- 1.5g/kg, and the daily protein requirement of 70kg patients is 84- 105g. Amino acids are often used to provide protein.

3. Fat: The daily fat requirement of adults is 0.8- 1.2g/kg, and that of 70kg patients is 56-84g. Vegetable oil is often used to provide fat.

4. Water and electrolyte: The water and electrolyte of patients need to be determined by blood test, including sodium, potassium, calcium, magnesium, chlorine and phosphorus.