What is total parenteral nutrition?

Some newborns can’t absorb sufficient nutrition through the stomach and intestine. This area is known as the gastrointestinal (GI) tract. In this case, they need to receive nutrients through a vein, or intravenously (IV).

In some infants, the GI tract functions well enough to allow some regular feedings, along with some IV feedings. This is called partial parenteral nutrition (PPN). Other infants must receive all of their nutrition via IV. This is called total parenteral nutrition (TPN).

TPN allows fluids to enter the body and provide nutrients while bypassing the GI tract. TPN delivers a combination of protein, carbohydrates, fats, vitamins, and minerals to an infant’s body. It also delivers electrolytes that help regulate nutrient balance at the cellular level.

When is total parenteral nutrition necessary?

Adults, children, and newborns can all benefit from TPN in certain cases. Adult patients and children may need TPN when they cannot get proper nutrition through normal eating or via a tube passed into the stomach. This may be due to inflammatory bowel diseases like Crohn’s disease or ulcerative colitis that cause severe diarrhea. It may also be due to short bowel syndrome after a large part of the small intestine is removed through surgery, due to a disease of the intestine. TPN is used when an infant is unable to receive food or liquids by mouth that will be delivered directly to the stomach. Infants may require TPN if they are sick or born prematurely.

Why do infants need total parenteral nutrition?

If sick or premature infants can’t properly absorb nutrients by mouth for an extended period it may be dangerous. The UCSF Children’s Hospital recommends that while it is always preferable for nutrition to be given via the GI tract, if this is not possible, then TPN may be started. Sick or premature newborns often have an increased need for nutrients. This may be due to factors such as:

  • diarrhea
  • dehydration
  • stunted kidney growth that prevents normal functioning
  • inadequate time in the womb, which prevents the infant from receiving their full supply of necessary nutrients for healthy growth and development.

According to the American Society for Parenteral and Enteral Nutrition (ASPEN), TPN can help save the lives of underweight or sick infants who are unable to process food taken by mouth or given by tube feedings to the GI tract. TPN offers a more effective way for these babies to meet their nutritional needs than through water-based IV feedings. This is because TPN provides more than just the sugars and salts available from IVs. A study in the medical journal Mayo Clinic Proceedings found that infants might benefit from TPN when oral feeding is impossible. These include premature infants with certain medical conditions and other infants with diarrhea and surgical problems. One review of 20 patients found that infants received enough calories to regain weight and continue to grow. A report in the medical journal Archives of Disease in Childhood studied the effectiveness of TPN versus milk in 34 infants who had very low birth weights. Researchers found that the TPN group had higher daily intakes of both protein and carbohydrates compared to the group fed with milk. The study concluded that TPN, when properly managed, could be an effective treatment for infants with very low birth weights. However, these studies were done in the early years of TPN use. Further experience has shown that TPN has a high risk of complications and is not routinely recommended for low birth weight infants who can receive nutrition via the GI tract.

How is total parenteral nutrition given to an infant?

TPN is given through a vein by placing an IV line into the baby’s hand, foot, scalp, or navel. Fluids are delivered via a “peripheral” route. This means nutrition is supplied through smaller veins that are less centrally located in the baby’s body. This is generally the method for PPN, used for short-term nutritional support. A longer IV may be used when an infant needs to receive ongoing TPN feedings. This is sometimes called a “central line.” A central linecan provide the infant with a greater nutrient concentration through larger veins.

What are the risks of total parenteral nutrition to an infant?

Though TPN can be lifesaving for infants who are not able to receive nutrition normally, it is not without risks. The Merck Manualreports that about 5 to 10 percent of patients of all ages have complications related to central line IV access. The following health problems often develop in infants through the use of TPN or IV lines for feeding:

  • liver problems
  • levels of fats, blood sugars, and electrolytes that are too high or too low
  • sepsis, a severe response to bacteria or other germs

The Merck Manualalso notes that chronic lung disease or high blood pressure may be a complication of fat intake through TPN. Liver problems due to TPN can develop at any age. However, they are most common in infants, particularly those who were born prematurely. This is because their livers are not yet fully developed. Liver problems most often occur when TPN is first started. Reducing the amount of protein in the IV mixture may help correct this. Healthcare providers caring for sick or premature infants closely monitor each infant’s nutritional needs by taking blood and urine tests. The results of these tests alert the medical team if the infant requires adjustments to the nutritional components of TPN.

What is the outlook for people on TPN?

According to the Parenteral Nutrition Fact Sheet issued by ASPEN, both children and adults can thrive using parenteral nutrition if no complications arise. Although parenteral nutrition is usually halted once the person is able to eat by mouth again, it can be continued for as long as necessary.