Nutrition: Total Parenteral Nutrition (TPN) & Refeeding Syndrome
(Gastroenterology 2001;121:966-69 & 970-1001)
GENERAL NUTRITION QUESTIONS/ANSWERS:
Ask yourself:
How long has the patient been without nutrition?
How malnourished is the patient?
Can you use the GI tract? If not, when can you use it?
Best predictive value of malnutrition is weight loss in preceding 3 months:
Severe protein-calorie malnutrition: loss of >20% of baseline weight; Begin supplemental nutrition immediately if NPO
Moderate protein-calorie malnutrition: loss of 10-20% of baseline weight; Begin supplemental nutrition within 2-3 days after NPO
Mild protein-calorie malnutrition: loss of <10% of baseline weight; Begin supplemental nutrition within 3-5 days after NPO
No protein-calorie malnutrition: no loss of baseline weight; Begin supplemental nutrition within 7-10 days after NPO; As long as fluids and electrolytes are maintained
Enteral (tube feed) vs. Parenteral (TPN): If the gut works, use it!
If the problem is dysphagia, gastroparesis, unwillingness to eat then the enteral route is indicated
For gastrostomy tubes and feeding formulas, See also Esophagus/Gastric- PEG Tubes (Chapter 1.20)
If the problem is digestion or absorption, then parenteral route is indicated
STEPS FOR WRITING TPN/PPN:
Determine energy (CHO) requirements (1st bag with half kcals for TPN, PPN can start full kcals); (Max with PPN: 700/L)
First bag of TPN should be 2-in-1 solution (PRO and CHO only, no FAT); So CHO/FAT: 100/0% First bag of PPN can be 3-in-1 solution; So CHO/FAT: 40/60%
Determine volume
Determine Electrolytes; Make adjustments daily; See back of TPN order form at some institutions
Determine calcium:phosphorous product (not to exceed 200)
Add adult vitamins, multiple trace elements and 120 mcg selenium daily if not included
Additions:
Famotidine (prevent stress ulcers): 40 mg/day standard, 20 mg/day renal dose
Insulin: (for BS control): A safe starting point is 0.1 units of insulin per 1 g of dextrose (i.e. CHO)
Calculation example: Say your TPN contains the following: 1200 total calories, CHO/FAT: 70/30%, PRO 100 gRelated posts:
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