Parenteral Nutrition Designing the Solution Mark H De

Parenteral Nutrition Designing the Solution Mark H. De. Legge, 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 § 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 m. Osmo) – May limit ability to deliver total caloric needs

PPN CPN Superior Vena Cava

Osmolality Gradient and Carbohydrates Glucose Concentration % Calories Kcal/L Osmolality m. Osmo/L 5 170 252 10 340 505 20 680 1010 40 1360 2020 50 1700 2525 60 2040 3030 70 2380 3535

Knowing the Solution § % Solution § 10% AA = 10 gm AA/100 H 20 § 20% Lipids = 20 gm lipids/100 cc H 2 O § 30% Jack Daniels = 30 gm Jack Daniels/100 cc H 20

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 § 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) Stress Factor Mild 1 -1. 2 Moderate 1. 3 -1. 4 Severe 1. 5

Simple Calorie Calculation § Maintenance/mild stress: 20 -25 kcal/kg/day § Moderate stress: 2528 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. 31. 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+ K+ Serum Chloride CO 2 BUN Creatinine Calcium Phosphorus Magnesium 135 -145 m. Eq/L 3. 5 -5. 0 m. Eq/L 98 -107 mmol/L 22 -32 mmol/L 8 -20 mg/d. L 0. 7 -1. 3 mg/d. L 8. 4 -10. 2 mg/d. L 2. 3 -4. 7 mg/d. L 1. 6 -2. 3 mg/d. L

Example of a Standard PN Electrolyte Matrix § § § NACl Na Acetate K Phosphate 75 m. Eq/L 25 m Eq/L (CO 2) 15 mmol § (3 mmol of P = 4. 4 m. Eq/K) § Na Phosphate 15 mmol § (3 mmol of P = 4 m. Eq Na) § Ca Gluconate § Mg sulfate 2 gm 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 Multivitamins Provided Daily § § § Vitamin A Vitamin D Vitamin E Vitamin B 1 Vitamin B 2 Vitamin B 3 Vitamin B 5 Vitamin B 6 Vitamin C Biotin Folic Acid Vitamin K 3300 IU 200 IU 10 IU 6 mg 3. 6 mg 40 mg 15 mg 6 mg 200 mg 60 mcg 600 mcg 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 § § § H 2 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

Important Facts § 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

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.

§ Calories § Protein § Fluids Estimated Needs 30 kcal/g x 70 kg = 2100 kcal 1. 2 g/kg x 70 kg = 84 kg 30 ml/kg = 2100 cc § His electrolytes are normal except for a K+ of 3. 3.

1 st Add Protein § § § 84 g of protein 4 kcal/g (326 kcal) 2100 kcal – 326 kcal = 1774 kcal more required

2 nd Add Lipids § § 1 -1. 5 g/kg 70 kg x 1 g/kg = 70 gm = 700 kcal 1774 calories – 700 kcal = 1074 kcal remaining

3 rd 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 H 20 – 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

Don’t leave Nutrition Support up to Someone Else