The document discusses parenteral nutrition (PN), also known as intravenous feeding. PN involves infusing nutrients directly into the bloodstream and bypassing the gastrointestinal tract. It summarizes the main components of PN including carbohydrates, protein, fat, electrolytes, vitamins and minerals. It provides guidelines on calculating and monitoring nutrient needs and doses for different patient populations, such as neonates and adults. Complications associated with PN administration involving catheter types and infections are also reviewed.