Which statement best describes total parenteral nutrition (TPN) compared with peripheral parenteral nutrition (PPN)?

• A. PPN uses a peripheral vein with more limited energy and nutrients.
• B. TPN uses a central venous line and provides the full nutrient needs.
• C. TPN is given via a peripheral vein with limited energy.
• D. PPN uses a central venous line and provides limited energy.

Answer: (B)

Central venous access is needed for total parenteral nutrition because the formulas are highly concentrated and must deliver all calories, protein, fluids, and micronutrients a patient needs. A central line allows these full-nutrient solutions to be given in the necessary volumes and with higher osmolarity safely, which is why TPN provides the complete energy and nutrient needs for a patient who cannot use the gut.

In contrast, peripheral parenteral nutrition is given through a peripheral vein with more dilute solutions to minimize irritation, so it can meet only a portion of the daily energy and nutrient requirements and is usually used for short-term or bridging support when central access isn’t available. Therefore, the statement that best describes TPN compared with PPN is that TPN uses a central venous line and provides the full nutrient needs.