When the digestive tract is inflamed or pushes food through the system too quickly — as is common with Crohn’s disease (CD) and ulcerative colitis (UC) — the intestines aren’t able to absorb all the vitamins, minerals, proteins, and calories people normally get from their food, explains Shirley Paski, MD, a gastroenterologist and the director of the small bowel diseases and nutrition program at Cedars-Sinai Medical Center in Los Angeles. Plus, an inflamed digestive tract burns more calories than it otherwise would, she says. Other times, ulcers or fistulas may cause nausea or diarrhea, which can lead to dehydration. In some extreme cases, a person’s intestines may fail completely, and they won’t be able to digest food at all. Whether it’s used as a short-term support or as a long-term food substitute, total parenteral nutrition (TPN) — sometimes called PN — administers liquid nutrition straight into a person’s bloodstream, bypassing a damaged digestive tract, according to the University of Pittsburgh Medical Center. All the calories, fats, carbohydrates, and other nutrients a person needs enter the body through an IV that’s threaded into a vein (usually in a person’s arm or chest), or through a more permanent catheter, says Stacy Cavagnaro, RD, who specializes in IBD at the Cleveland Clinic. Total parenteral nutrition can be a lifesaving alternative for people who suffer from malnutrition because of IBD, she explains.
TPN Provides Nutritional Support, Not a Cure
It’s important to understand that TPN is not a therapy for IBD and will not treat the underlying disease, says Dr. Paski. What it does do is treat malnutrition, a common side effect of CD and UC, and one that can increase the risk of complications of the disease. “We don’t like to jump to TPN right away,” says Cavagnaro. “We usually start with prescribing a high-calorie, low-sugar diet and frequent meals to get a person’s weight up. We’ll try diet supplements and then would try tube feeding next. If that fails, then we consider TPN.” Though it’s unclear how many people with IBD ultimately receive TPN as part of their nutritional care, a 2017 review of the National Inpatient Sample (NIS) database published in the Journal of Critical Care found that more than 40,000 people in the United States received TPN in institutions in 2012. People suffering from IBD who are candidates for TPN usually won’t need the nutrition therapy long-term, though it is possible. Paski says IV nutrition like TPN is more commonly used as a bridge for patients with IBD— either to prepare a patient for surgery, as temporary support while the bowel adapts after a large intestinal resection, or until IBD symptoms such as bowel obstruction can be fixed. “It’s much less common for someone to require TPN permanently,” she says. “Those are just in cases of true intestinal failure. The goal especially with IBD is to correct the underlying problem.” According to a review of nutritional support tactics for patients with IBD, published in 2018 in the journal Gastroenterology Research and Practice, the risk of surgery for people who have Crohn’s disease is about 50 percent after 10 years of living with the disease. Around 40 percent of people with ulcerative colitis will eventually have a proctocolectomy — a procedure that surgically removes the rectum and part of the colon. The review also found that around 70 percent of people with IBD, especially CD, are malnourished. “Malnutrition increases risk during surgery and leads to longer post-op hospital stays, so some patients with IBD may receive TPN prior to surgery to prevent that,” says Cavagnaro, who also notes that these patients typically don’t need TPN for very long after the operation.
Understanding the Risks of Total Parenteral Nutrition
Even in the short-term, there are inherent risks to TPN. Cavagnaro says infection poses the biggest threat. Patients who require TPN for more than a few weeks may get a Hickman catheter, which stays in the chest and has to be changed less frequently than other catheters, like those used to deliver TPN through veins in the arm over shorter periods of time, she notes. The catheter is placed in the chest cavity through a minimally invasive procedure and lasts for up to 10 years. These catheters carry a lower risk of infection, but if one does develop, catching it immediately is even more important than elsewhere in the body. That’s because the catheter feeds a major vessel that goes straight to the heart and can cause sepsis, Cavagnaro explains. Learning how to recognize early signs of infection, such as the sudden onset of fever, shaking, or chills, or if the skin around the catheter burns or feels hot to the touch or there’s pus, is crucial to minimizing risk. “Anyone receiving TPN who notices a sudden onset of a fever or notices any change in the area surrounding the central line should contact their healthcare provider and go to the ER immediately,” says Cavagnaro. Other risks have to do with the effect long-term use has on a person’s health. “When people are on this for decades, they’re at higher risk for osteoporosis, which people with IBD are already at a much higher risk for,” says Cavagnaro, who notes that over time, TPN is also hard on the liver, and people who require it for a lifetime may eventually need a liver transplant. Patients can minimize impact by working with a registered dietitian who specializes in TPN, she adds. An expert can help patients reduce the number of hours or days per week they need to be on IV nutritional therapy.
Living With Long-Term Total Parenteral Nutrition
According to Paski, in some cases, long-term TPN is deemed the best, or only, way a person can get the nutrients they need but can no longer get through food. People who suffer from CD are more likely to need TPN than someone who suffers from UC, says Cavagnaro. That’s because CD can affect the entire GI tract from mouth to anus, whereas UC affects the colon. Since the small intestine is where the body takes in most nutrients, a person who has had a significant portion of their small intestine removed may need TPN over the long term, adds Cavagnaro. A lower intestine that’s smaller than 200 centimeters (about 79 inches) leads to short bowel syndrome, she says. “When it gets shorter than 150 centimeters (59 inches), people have a lot of problems absorbing not only their food but electrolytes and fluids.” In these cases, when long-term TPN is required, both Cavagnaro and Paski stress that the goal of both patient and provider should be to minimize the impact TPN has on a person’s quality of life. Chest catheters are easily concealed by shirts. Backpacks and purses that are designed to carry TPN equipment can minimize the amount of time people spend tethered to the privacy of their homes. “You thread the line through your shirt and put the bag in a backpack or purse so you can just take it to work or run errands and nobody can tell,” says Cavagnaro. Although care can usually be managed with a surgeon, gastroenterologist, and primary care doctor, Paski recommends that people who are on TPN long-term work with a multidisciplinary program that specializes in it. Doctors at the Cleveland Clinic’s Center for Gut Rehabilitation & Transplantation combine TPN with other therapies, including medication, to help food move more slowly through the digestive system, which may help people absorb more food through their GI tract in the long run. Surgical procedures can elongate small intestines over time and can alleviate obstructions. Cleveland Clinic also created the IBD patient-centered medical home, which provides integrative care to people affected by IBD. University Hospitals in Cleveland, Ohio, and Cedars-Sinai’s Small Bowel Disease and Nutrition Program in Los Angeles also provide specialized care for long-term TPN. “These experts from different fields can make recommendations regarding long-term follow-up care and weaning,” says Paski, who recommends that long-term patients occasionally ask about new treatment options they may be eligible for that could help them be less dependent on TPN. Paski says a lot of her patients also see mental health providers. “We try to make it as easy as possible, but living on TPN is a different way of life from what most people experience,” she says. Food plays a major role in society, and “it can be isolating for patients who are on TPN because they are literally unable to eat,” she says. Being a permanent medical patient can also be emotionally taxing, and emotional support is an important part of nutrition therapy. Paski recommends joining online and in-person support groups like the Oley Foundation and the Crohn’s & Colitis Foundation.
