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Parenteral Nutrition Designing the Solution. Mark H. DeLegge, MD, FACG, AGAF, FASGE Digestive Disease Center Medical University of South Carolina. Avoid That Which is Unknown. Lipids. Protein. Carbohydrates. Parenteral Nutrition. Infusion of nutrients through a vein
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Parenteral NutritionDesigning the Solution Mark H. DeLegge, MD, FACG, AGAF, FASGE Digestive Disease Center Medical University of South Carolina
Lipids Protein Carbohydrates
Parenteral Nutrition • Infusion of nutrients through a vein • Indications: dysfuntional GI system • Malabsorption • Obstruction • Fistula • Inability to obtain enteral access • Bowel rest ?
Parenteral Nutrition • Central: Infused into a major vein (CPN) • Generally with catheter tip in the last 1/3 of Superior Vena Cava • Peripheral: Infused into a peripheral vein (PPN) • Limited by mixture osmolality (< 900 mOsmo) • May limit ability to deliver total caloric needs
PPN CPN Superior Vena Cava
Knowing the Solution • % Solution • 10% AA= 10 gm AA/100 H20 • 20% Lipids= 20 gm lipids/100 cc H2O • 30% Jack Daniels= 30 gm Jack Daniels/100 cc H20
What You Need to Know To Write A PN Prescription • Calorie Requirements • Protein Requirements • Electrolyte Requirements • Mineral Requirements • Vitamin Requirements • Water Requirements • Other Additives
Calorie Needs Stress Factor Mild 1-1.2 Moderate 1.3-1.4 Severe 1.5 • Harris Benedict: • Male 66 + 13.8 (wt in kg) + 5 (height in cm) – 6.8 (age in years) • Female 655 + 9.6 (weight in kg) + 1.8 (ht in cm) – 4.7 (age in years)
Simple Calorie Calculation • Maintenance/mild stress: 20-25 kcal/kg/day • Moderate stress: 25-28 kcal/kg/day • Severe Stress : 28-35 kcal/kg/day
Protein Needs • Maintenance – mild stress: 0.8-1.2 g/kg/day • Moderate stress: 1.3-1.5 gm/kg/day • Severe stress: 1.5 – 2.0 gm/kg/day • Very high stress: > 2 gm/kg/day
Make Note of Common Lab Values Na+ 135-145 mEq/L K+ Serum 3.5-5.0 mEq/L Chloride 98-107 mmol/L CO2 22-32 mmol/L BUN 8-20 mg/dL Creatinine 0.7-1.3 mg/dL Calcium 8.4-10.2 mg/dL Phosphorus 2.3-4.7 mg/dL Magnesium 1.6-2.3 mg/dL
Example of a Standard PN Electrolyte Matrix • NACl 75 mEq/L • Na Acetate 25 m Eq/L (CO2) • K Phosphate 15 mmol • (3 mmol of P = 4.4 mEq/K) • Na Phosphate 15 mmol • (3 mmol of P = 4 mEq Na) • Ca Gluconate 2 gm • Mg sulfate 1 gram
Standard Trace Minerals • Added to Daily PN Prescription • Chromium 10 mcg • Copper 1 mg • Manganese 0.5 mg • Selenium 60 mcg • Zinc 5 mg
Standard MultivitaminsProvided Daily • Vitamin A 3300 IU • Vitamin D 200 IU • Vitamin E 10 IU • Vitamin B1 6 mg • Vitamin B2 3.6 mg • Vitamin B3 40 mg • Vitamin B5 15 mg • Vitamin B6 6 mg • Vitamin C 200 mg • Biotin 60 mcg • Folic Acid 600 mcg • Vitamin K 150 mcg
Daily Fluid Needs • 30 cc/kg/day • Reduce if volume overloaded • Increase for excessive stool, urine, vomiting, sweating. • You do not have to correct major electrolyte, mineral, fluid abnormalities in the PN solution. Use a supplemental infusion.
Additives • H2 Blocker • Heparin • Insulin • Need at least 10 units/L to see clinical effect • Add ½ to ¾ of previous day’s insulin requirements to TPN bag
Additional Potential Additives Vitamin C: 500-1000 mg/day for wound healing. Zinc: 3-5 mg/day for wound healing Folic Acid: 1 mg/day with alcohol abuse or pregnancy Thiamine: 100 mg/day with alcohol abuse
Lipids: no more than 2.5 gm/kg/day Carbohydrates: Maximal glucose infusion rate 3-5 g/kg/day Protein: as described 1 gram lipids = 9 kcal 1 gram protein = 4 kcal 1 gram carbohydrates = 3.4 kcal Important Facts
The Situation • A 40 year old male s/p recurrent fistula formation in the distal jejunum. He has lost 6 kg in 2 weeks. A central PN catheter is placed and you are asked to write a PN order. The patient weighs 70 kg.
Estimated Needs • Calories 30 kcal/g x 70 kg = 2100 kcal • Protein 1.2 g/kg x 70 kg = 84 kg • Fluids 30 ml/kg = 2100 cc • His electrolytes are normal except for a K+ of 3.3.
1st Add Protein • 84 g of protein • 4 kcal/g (326 kcal) • 2100 kcal – 326 kcal = 1774 kcal more required
2nd Add Lipids • 1-1.5 g/kg • 70 kg x 1 g/kg = 70 gm • 70 gm = 700 kcal • 1774 calories – 700 kcal = 1074 kcal remaining
3rd Add Carbohydrates • 1074 kcal remaining • 1074/3.4 kcal/g carbohydrate = 295 g • Double check for maximal carbohydrate infusion • 295 g carbohydrate/70 kg = 4.21 g/kg/day
Determine a Volume • 70 kg x 30 cc/kg = 2100 cc • Add multivitamins • Add trace minerals • Add drugs if necessary
What if the TPN Form Asks Me to Add Components as Solutions? 15% amino acids (15 gm/100 cc) We need 84 grams = 560 cc 20 Lipids (20 gm/100 cc) We need 70 gm = 350 cc 70% dextrose (70 gm/100 cc) We need 295 gm = 421 cc 2100 cc volume – 1361 cc = 739 cc H20 Add trace minerals, multivitamins and other drugs
How do you Determine a Rate • Continuous • Total volume/24 hr = cc/hr • 2100/24 = 87 cc/hr • Intermittent • Total volume over 12 hours • 2100/12 = 175 cc/hr
Conclusion • 1. Be able to determine calorie, protein, fluid needs • 2. Be familiar with a standard electrolyte formulation • 3. Make your PN formula sequentially • 4. Be familiar with solutions and what they mean • 5. Add this to your knowledge base