Total Parenteral Nutrition and Central-Line Safety

Parenteral nutrition (PN) supplies glucose, amino acids, lipids, electrolytes, vitamins, minerals, and fluid directly into the bloodstream. In practice, “TPN” commonly refers to PN delivered through a central venous catheter, often at a concentration too hyperosmolar for a peripheral vein. This route bypasses the gastrointestinal tract, so it can sustain nutrition when the gut cannot be used, but it also creates a direct pathway into the circulation. For critically ill adults, enteral nutrition is preferred whenever the gastrointestinal tract is functional. PN is generally initiated only when the gut cannot be used or when enteral feeding does not provide at least 60% of caloric needs after 7 days. The decision is not based on the presence of an empty stomach alone; it depends on gastrointestinal function, the patient’s nutritional risk, expected duration of inadequate intake, and the balance between feeding benefit and line-related harm. TPN combines two safety problems. The formulation can rapidly change glucose, electrolytes, triglycerides, liver function, and fluid status. The catheter can introduce infection, air, thrombosis, or mechanical injury. The experienced nurse therefore looks at the patient...