TotalParenteralNutrition

Total Parenteral Nutrition, often abbreviated as TPN, is the intravenous delivery of a complete nutritional solution that provides energy and the major nutrients required for growth, maintenance, and recovery when the gastrointestinal tract cannot be used for feeding. It is designed to meet daily needs for calories, protein, fats, vitamins, minerals, and fluids and is typically administered through a central venous catheter due to the high osmolarity of the solutions. TPN is used in patients with severe pancreatitis, bowel obstruction, short bowel syndrome, extensive postoperative states, and other conditions that preclude safe enteral nutrition.

Formulations of TPN combine carbohydrate in the form of dextrose, protein as amino acids, and fats as an emulsion, along with electrolytes, water-soluble vitamins, and trace elements. The exact mix is individualized by clinicians or dietitians based on age, weight, illness, and metabolic status. Caloric goals generally range from about 25 to 35 kcal per kilogram per day, with protein targets around 1.0 to 2.0 g/kg/day, adjusted for stress, infection, or organ dysfunction.

Administration is via a central venous line; peripheral infusion is possible for short-term, low-osmolar regimens but is uncommon for full TPN. Infusion can be continuous or cyclic, with careful monitoring of glucose levels, fluid balance, and energy administration to avoid overload or deficiency.

Monitoring includes daily weight, intake and output, and laboratory measures of electrolytes, glucose, liver and kidney function, and triglycerides. Regular assessment for catheter-related infection and other complications is essential. Safety practices emphasize aseptic technique and diligent line care.

Common complications include catheter-related bloodstream infection, metabolic disturbances such as hyperglycemia or hypoglycemia, electrolyte imbalances, hepatic steatosis or cholestasis with long-term use, and potential essential fatty acid deficiency if lipids are withheld. TPN has evolved since its development in the 1960s by researchers including Stanley Dudrick and remains a critical option for patients with intestinal failure or nonfunctional gut when enteral feeding is not feasible.