What is a common reason for total parenteral nutrition (TPN)?

Total parenteral nutrition (TPN) is often utilized when a patient is unable to obtain adequate nutrition through oral intake or enteral route. Being NPO (nil per os), which means "nothing by mouth," for an extended period, such as more than 5 to 7 days, is a common indication for TPN. During this time, the body still requires essential nutrients to maintain metabolic function, and TPN provides a means to supply these nutrients directly into the bloodstream.

Patients in this situation may be recovering from surgery, have conditions affecting their ability to eat, or suffer from gastrointestinal disorders which make it unsafe or impossible to consume food. TPN ensures that they receive the necessary proteins, fats, carbohydrates, vitamins, and minerals their bodies require for healing and maintaining bodily functions during the period they are unable to eat by mouth.