Total parenteral nutrition (TPN) is a life-saving medical therapy that delivers essential nutrients directly into the bloodstream (parenterally), i.e., bypassing the gastrointestinal system. It is used when feeding by mouth or through a nasogastric tube is not possible due to gastrointestinal disorders (e.g., short bowel syndrome, bowel obstruction), severe malnutrition, or cancer-related nutritional deficiencies. TPN is also used for preoperative or postoperative nutritional support.^[1][2][3][4]

TPN is administered intravenously, typically through a central vein, and contains a balanced mixture of carbohydrates (sugars), proteins (amino acids), fats (fatty acids and triglycerides), electrolytes, vitamins, and trace elements. The composition of TPN is customized based on the patient’s specific nutritional requirements.^[1][2][3][4] This method of feeding provides all the patient’s nutritional requirements, hence the word total as opposed to partial parenteral nutrition, which provides only part of the patient’s daily nutritional requirements.

Despite its benefits, TPN carries potential risks, including infection risk from using intravenous catheters, metabolic imbalances such as electrolyte disturbances, and liver dysfunction from prolonged use.^{[1][2][3][4][5][6]} Due to these risks, TPN requires careful medical supervision and regular adjustments to ensure both safety and adequate nutritional support.