What Is Total Parenteral Nutrition?
Some newborns cannot absorb sufficient nutrition through the stomach and intestine, collectively known as the gastrointestinal (GI) tract. Therefore, 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, which help keep the body hydrated.
When Is Total Parenteral Nutrition Necessary?
This technique is used when an infant is unable to or should not receive food or liquids by mouth.
Adults, children, and newborns can all benefit from TPN in certain circumstances. Adult patients and children may need TPN when they cannot get proper nutrition through normal eating. This may be due to inflammatory bowel diseases such as severe diarrhea, Crohn’s disease, or ulcerative colitis. It may also be due to surgery-related short bowel syndrome (a large part of the small intestine is removed through surgery, due to a disease of the intestine).
Infants may require TPN if they are sick or born prematurely.
Why Do Infants Need Total Parenteral Nutrition?
If sick or premature infants cannot properly absorb nutrients by mouth for an extended period, their lives may be endangered. Therefore, UCSF Children’s Hospital recommends that infants who need support from TPN nutrition start receiving it within three days of birth (UCSF, 2006).
Sick or premature newborns often have an increased need for nutrients. This may be due to factors such as:
- stunted kidney growth (prevents normal functioning)
- inadequate time in the womb (prevents the infant from receiving his or her full supply of necessary nutrients for healthy growth and development)
According to the National Institutes of Health (NIH), where the infant is unable to process food taken by mouth, TPN can help save the lives of underweight or sick infants. This is because TPN offers a more effective way for these babies to meet their nutritional needs than through aqueous IV feedings. This is because it provides more than just sugars and salts available from aqueous IVs (NIH, 2011).
A study in the medical journal Mayo Clinic Proceedings found that premature infants—as well as infants with diarrhea and surgical problems that made by-mouth feeding impossible—benefitted from TPN. In the study, which was a yearlong review of 20 patients, infants received enough calories to regain weight and continue to grow (Feliciano & Telander, 1976).
A separate study reported 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 there were higher daily intakes of both protein and carbohydrates in the TPN group when compared to the milk group. The study concluded that TPN can be an effective treatment for infants with very low birth weights when properly managed (Yu, James, Hendry, & Macmahon, 1979).
How Is Total Parenteral Nutrition Given to an Infant?
TPN is provided 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 case with PPN 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 line can 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 Manual for Health Care Professionals reports that around five to 10 percent of patients (of all ages) have complications related to central-line IV access (Merck, 2009).
The following health problems may 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 Manual for Health Care Professionals also notes that chronic lung disease or high blood pressure may be a complication of fat intake through TPN (Merck, 2009).
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 (Merck, 2009).
Healthcare providers caring for sick or premature infants must closely monitor each infant’s nutritional needs. They can do so by using blood and urine tests, which will alert the medical team if the infant requires adjustments to the nutritional components of TPN.