Which vascular access route is typically required for total parenteral nutrition?

• A. Arterial line.
• B. Peripheral vein.
• C. Portal vein.
• D. Central venous line.

Answer: (D)

Total parenteral nutrition must enter the central circulation because it’s a highly concentrated, hyperosmolar solution that often includes lipids, amino acids, and glucose in large volumes. A central venous line places the catheter into a large central vein (like the subclavian or internal jugular) where there is rapid dilution by the high-flow blood, reducing the risk of vein irritation and allowing safe, continuous administration and lipid delivery over time. Peripheral veins can’t tolerate the osmolarity or volume and are prone to phlebitis and infiltration. An arterial line is used for monitoring, not nutrition, and access via the portal vein isn’t used for routine TPN.