Compare and contrast peripheral parenteral nutrition and total parenteral nutrition

Answer 1

In peripheral parenteral nutrition, nutrients are delivered using only the peripheral veins. The peripheral veins can be damaged by overly concentrated solutions, though. To prevent complications, the osmolarity of PPN is kept below 900 milliosmoles per liter, a concentration that limits the amounts of energy and protein the solution can provide. PPN is most often used in patients who require short-term nutrition support and who do not have high nutrient needs or fluid restrictions. Most patients meet their nutrient needs using the larger, central veins, where blood volume is greater and nutrient concentrations do not need to be limited. This method can reliably provide all of a person's nutrient requirements and therefore is called total parenteral nutrition (TPN). Because the central veins carry a large volume of blood, the parenteral solutions are rapidly diluted; thus, patients with high nutrient needs or fluid restrictions can receive the nutrient-dense solutions they require. TPN is also preferred for patients who require long-term parenteral nutrition.