total parenteral nutrition

1. Feezor Chief Roundtable December 19, 2005 Total Parenteral Nutrition Robert J. Feezor, MD University of Florida Department of Surgery

2. Feezor Chief Roundtable December 19, 2005

3. Feezor Chief Roundtable December 19, 2005 When to use TPN �If the gut works, use it!� Assess patient�s nutritional status History Weight loss Anorexia Weakness Inability to carry out normal functions Disease process that interferes with intake Physical Muscle wasting Loose skin Edema of hypoproteinemia Loss of body fat

4. Feezor Chief Roundtable December 19, 2005 Nutritional assessment Indirect calorimetry BEE (Harris-Benedict Equation) Based on sex, weight, height, age RQ = CO2 produced / O2 consumed RQ = 1.0, pure CHO metabolism RQ = 0.7, fat metabolism RQ < 0.7, ketogenesis Anthropometric measurements Triceps skinfold measurements IBW (males) = 48 kg + 2.7 kg for each inch over 5�0� IBW (females) = 45.5 kg + 2.3 kg for each inch over 5�0�

5. Feezor Chief Roundtable December 19, 2005 Nutritional assessment Functional studies of muscle Biochemical measurements Albumin (3.0 g/dL) Prealbumin Nitrogen balance (Protein in (g)/ 6.25) � urinary urea Protein breakdown Immunologic function

6. Feezor Chief Roundtable December 19, 2005 Malnutrition sequelae >10% weight loss: Increased LOS Increased incidence of nosocomial infections Increased mortality 7-10 days of malnutrition: Impaired complement and Ig production Dysfunctional leukocyte chemotaxis, phagocytosis, oxidative burst Poor tissue repair Loss of muscle function: ventilator dependence Up to 50% of inpatients are malnourished

7. Feezor Chief Roundtable December 19, 2005 How to write TPN Specific Fuels Theory Practical Information

8. Feezor Chief Roundtable December 19, 2005 Basic TPN Calculate MIVF rate: 4 � 2 � 1 rule 65 kg female 10 x 4 = 40 10 x 2 = 20 45 x 1 = 45 TOTAL = 105 1 L = 42 mL / hr 1.5 L = 63 mL / hr 2 L = 84 mL / hr Specific fuels: Carbohydrate Fats Amino Acids In general, amino acids are not included in kcal/kg figures: �non-protein calories�

9. Feezor Chief Roundtable December 19, 2005 Carbohydrate 3.4 kcal / g (anhydrous) �Protein-sparing effect� by Gamble (1940) As little as 100g glucose per 24h will decrease urinary urea production Suppresses hepatic gluconeogenesis (avoids protein breakdown) Exogenous glucose obviates need for amino acids as energy fuel D5�NS @ 84 mL/hr = 100g dextrose per day

10. Feezor Chief Roundtable December 19, 2005 Carbohydrate 3.4 kcal / kg (anhydrous) �Protein-sparing effect� by Gamble (1940) Excess glucose administration Converted to fat in the liver: de novo lipogenesis Immunosuppressant, increasing nosocominal infections ICU control 1: 1548 patients all receiving 25 kcal/kg parenterally or enterally Randomized to 180-200mg/dL or 80-110mg/dL Mortality decreased by 42% in �tight glucose control� group

11. Feezor Chief Roundtable December 19, 2005 Carbohydrate Start at 150g per day What % Dextrose is this? Why start here? For a 70 kg person, this is 7.3 kcal/kg (150 g x 3.4 kcal/g) / (70 kg) Increase by 50 g per day Watch PO4, which will decline �Refeeding syndrome� Check CS q6h Adjust insulin in HAL to decrease SSI requirements

12. Feezor Chief Roundtable December 19, 2005 Fat Optimally, 25% of nonprotein calories Major source of fuel during starvation During minor stress, CHO and fat utilization are indistinguishable in terms of Nitrogen balance At some point during sepsis, fat utilization is impaired Calorically dense (9 kcal/g)

13. Feezor Chief Roundtable December 19, 2005 Fat Lipid accumulation in the liver overloads the Kupffer cells (hepatic macrophages) Inhibits reticuloendothelial system Excess lipid administration may increase PGE2 and thromboxane A2 Decreases the ability of the pulmonary hypoxic vasoconstriction Worsens gas diffusion, oxygenation in ARDS The phospholipid emulsifying portion of IL solution can interfere with lipoprotein lipase Can increase serum triglycerides Don�t administer IL in patients with TG>400

14. Feezor Chief Roundtable December 19, 2005 Fat Start on 2nd day Check TG on day#1 Why else do we wait? 250-500 mL per day 12 on / 12 off Shands formula has 2 kcal / mL 500 mL = 42 mL/h x 12h 500 mL = 1000 kcal (14.3 kcal/kg if 70 kg)

15. Feezor Chief Roundtable December 19, 2005 Amino Acids 70 kg man has 10 kg protein �Lean body mass� Turnover is 3% per day in the fed state Largest component is shed enterocytes (gut) Protein requirement deceases with age Protein requirement in adults: 0.8g/kg 60g per day Maximal protein-sparing achieved when subjects given 1.5 g/kg per day 4 kcal / g

16. Feezor Chief Roundtable December 19, 2005 Amino Acids Start at 1 g / kg Increase to 1.5 g / kg on day #2 Check BUN Avoid if renal dysfunction

17. Feezor Chief Roundtable December 19, 2005 Electrolytes Another topic. . . . �Like steroid tapers� � AKL Largely, trial and error Use NaCl, K Acetate Daily BMPs Adjust

18. Feezor Chief Roundtable December 19, 2005 Trace elements Thiamine, folate, selenium Change Zantac to HAL (150 mg/day) CHANGE BACK when off TPN Zinc, vitamin C for healing

19. Feezor Chief Roundtable December 19, 2005

20. Feezor Chief Roundtable December 19, 2005 Writing TPN A Case Example

21. Feezor Chief Roundtable December 19, 2005 Writing TPN: what to know What is the patient�s weight? 70kg How many calories? 30kcal/kg How much CHO and Fat? 2/3 & 1/3 How much Protein? 1.5 g/kg Example� 70kg = 2100 kcal CHO = 1400 kcal FAT = 700 kcal

22. Feezor Chief Roundtable December 19, 2005 Writing TPN: Day 1 Volume? CHO 1400 kcal = 411 g FAT 700 kcal = 350 mL Protein 1.5 g/kg = 105 g

23. Feezor Chief Roundtable December 19, 2005 Writing TPN: Day 2 Volume? CHO 1400 kcal = 411 g FAT 700 kcal = 350 mL Protein 1.5 g/kg = 105 g