Parenteral nutrition-refers to the supply of nutrients from outside the intestines, such as intravenous, intramuscular, subcutaneous, intra-abdominal, etc. The main route is intravenous, so parenteral nutrition can also be called intravenous nutrition in a narrow sense.
Intravenous nutrition-refers to a treatment method that provides nutrition to patients through intravenous routes.
The composition of parenteral nutrients-mainly sugar, fat, amino acids, electrolytes, vitamins, and trace elements.
The supply of parenteral nutrition-varies with patients and disease states. The general adult’s calorie requirement is 24-32 kcal/kg·d, and the nutritional formula should be calculated based on the patient’s weight.
Glucose, fat, amino acids and calories-1g glucose provides 4kcal calories, 1g fat provides 9kcal calories, and 1g nitrogen provides 4kcal calories.
Ratio of sugar, fat and amino acid:
The best energy source in parenteral nutrition should be the dual energy system composed of sugar and fat, that is, non-protein calories (NPC).
(1) Heat nitrogen ratio:
Generally 150kcal: 1g N;
When traumatic stress is severe, the supply of nitrogen should be increased, and the heat-nitrogen ratio can even be adjusted to 100kcal:1g N to meet the needs of metabolic support.
(2) Sugar to lipid ratio:
In general, 70% of NPC is provided by glucose and 30% is provided by fat emulsion.
When stress such as trauma, the supply of fat emulsion can be appropriately increased and the consumption of glucose can be relatively reduced. Both can provide 50% of energy.
For example: 70kg patients, the proportion of intravenous nutrient solution.
1. Total calories: 70kg×(24——32)kcal/kg·d=2100 kcal
2. According to the ratio of sugar to lipid: sugar for energy-2100 × 70% = 1470 kcal
Fat for energy-2100 × 30% = 630 kcal
3. According to 1g glucose provides 4kcal calories, 1g fat provides 9kcal calories, and 1g nitrogen provides 4kcal calories:
Sugar amount = 1470 ÷ 4 = 367.5g
Fat mass = 630 ÷ 9 = 70g
4. According to the ratio of heat to nitrogen: (2100 ÷ 150) ×1g N = 14g (N)
14×6.25 = 87.5g (protein)
Post time: Jul-16-2021