HPN Patients: Questions for your doctor

Questions you should ask your doctor if you are on long-term home parenteral nutrition

Shirley Paski, MD

 

Why am I on TPN?

  • Hydration?
  • Electrolytes?
  • Calories from fat, protein, carbohydrates?
  • Vitamins and minerals?

 

Is there a way to make my gastrointestinal system function so that I don’t need TPN, or need less TPN?

  • Significant individual variation
  • Unable to eat enough food
    • Nausea, vomiting
    • Abdominal pain, distention
    • Diarrhea
    • Obstruction
  • Maldigestion
    • Unable to break down food into particles that can be taken up into intestinal cells
  • Malabsorption
    • Not enough intestine,
    • Intestines are damaged, and/or
    • Rapid transit of food through the intestines, without enough time to be absorbed

 

What vitamin and mineral deficiencies am I at risk for developing? 

  • Depends on which part of your gastrointestinal tract is missing and how well your other organs like the pancreas and liver function
  • In short bowel syndrome, fat-soluble vitamin deficiency, vitamin B12, magnesium, and potassium deficiencies are most common
  • Iron deficiency is common in home parenteral nutrition because iron is not in the TPN

 

How often should I be getting labs done to make sure I’m not developing nutritional deficiencies or toxicities?

  • Variable, and depends on how ‘dependent’ you are on TPN vs oral diet vs tube feeding
  • General guide that I follow (with individual modifications):
    • MONTHLY: CBC, CMP, magnesium, phosphorus, INR, CRP, pre-albumin, triglycerides
    • EVERY 3-6 MONTHS: Iron indices, zinc, selenium, copper, carnitine (pediatric patients)
    • EVERY 6-12 MONTHS: Vitamin B12, folate, vitamin A, vitamin E, 25-OH vitamin D, vitamin C, chromium, manganese
    • ANNUAL: PTH, TSH, full lipid profile; 24-hour urine sodium, creatinine, calcium

 

What are the possible long-term effects of TPN on my body?

  • Long-term effects of TPN can be directly caused by TPN, the result of underlying gastrointestinal disease, lack of nutrient exposure to the gut, fluctuations in hydration/electrolytes, or to IV access.   
  • Nutritional – over/under nutrition, vitamin/mineral deficiencies or toxicities
  • Liver – elevated liver enzymes
  • Chronic renal (kidney) injury – low glomerular filtration rate (GFR)
  • Metabolic bone disease – osteoporosis, osteopenia
  • Central catheter and IV access – line infections, blood clots, difficult IV access

 

How can I reduce my chance of developing long-term complications related to TPN?

  • Screen for complications and take a preventative/early management approach
  • TPN associated liver disease
    • Cause: Fatty liver, impaired liver function, and/or gallbladder/bile flow problems
    • Diagnostic test: elevated liver enzymes
    • Management: Avoidance of infections, optimize the use of oral/enteral nutrition, and/or changes in your TPN formula
  • Chronic renal injury
    • Cause: Usually from fluctuations in hydration or dehydration, kidney stones
    • Diagnostic test: low glomerular filtration rate (GFR or eGFR), monitor your urine output periodically, want >1L urine/24 hours
    • Management: Maintain adequate hydration and acid/base status which is managed through a combination of diet/lifestyle, medications, and changes in your TPN formula
  • Central line infections
    • Cause: Line infections can arise from difficulty in sterile technique, from an infection somewhere else in the body, or from movement of bacteria/fungi across the intestinal wall into the bloodstream
    • Diagnostic test: blood cultures, taken from the line & also from a peripheral vein (skin poke)
    • Management: Meticulous central line care, prompt management of infections with antibiotics, may require antibiotic or ethanol treatment of line
  • Central line blood clots and IV access
    • Cause: Imbalance in blood clotting/clot breakdown proteins, type of catheter
    • Diagnostic test: with limb/neck swelling  ultrasound or scan showing a blood clot