1. Nutrition in Surgical Patients Ronald Merrell, MD Chairman of Surgery Virginia Commonwealth University

2. What? Carbohydrate Lipid Protein Trace elements Vitamins

3. Who? Malnourished (>10% lean body mass) Incapable of eating (>10 days)

4. Why? Risks of malnutrition including infection, poor healing and higher mortality Malnutrition is exacerbated by physiological stress

5. When? Preoperative? Early? Late? ---after initial resuscitation following injury or surgery

6. How? Parenteral Enteral Total Partial

7. Issues Metabolic response to injury Cytokines, inflammation, hormones Biology of substrates Enteral vs. Parenteral

8. “Ashen faces, a thready pulse and cold clammy extremities…” The Ebb Phase Cuthbertson, Quart. J. Med.25:233,1932

10. The Ebb Phase Hypometabolic Hypothermic Hypoinsulinemic Hypoperfusion Hypercortisolism Hyperglucagonemia Hyperglycemia Hypercatecholemia

11. “The patient warms up,cardiac output increases and the surgical team relaxes…” The Flow Phase Cuthbertson. Lancet 1:233, 1942

12. The Flow Phase Hypermetabolic Hyperthermic Catabolic Hyperinsulinism Hypercortisolism Hyperglucagonemia High cardiac output

13. Nutritional Assessment Body weight Body mass index creatinine height index Serum proteins:albumin, prealbumin, transferrin Immune competence: lymphocytes, DH Nitrogen balance

14. Caloric Requirement Formula Indirect calorimetry PRN for nitrogen balance Approximation

15. Nutritional Requirements 25 cal/kg/day carbohydrate ~70% Lipid 15-30% Protein 1.5-2.0g/kg/day. Not for calories Additional 50% to 100% for stress as in ICU patients

16. Nutritional Goals Nitrogen balance Preserve or restore visceral protein Reduce morbidity Reduce mortality Reduce hospital stay

18. Early Enteral Feeding: a meta- analysis Eight prospective randomized trials with trauma and high risk surgical patients(118 enteral, 112 parenteral) Septic complications:enteral 18%, parenteral 35% Moore. Ann. Surg. 216:172,1992

19. Parenteral requirements Dilution in right heart return because of hyperosmolarity…….Central Venous Line Delivery of simple carbohydrate (20%glucose) Lipid emulsion Amino acids

20. Enteral Requirements Delivery into the GI tract by tube with minimum risk of aspiration or patient effort Delivery of nutrients with minimal need for digestion Control of rate to prevent osmotic diarrhea

21. Advantages of enteral nutrition Easier GI bacterial translocation Cheaper Fewer specific complications

22. Nutrients with specific putative contributions Branch chain amino acids Glutamine Arginine Nucleotides Omega-3 fatty acids

23. Immune Enhancing Diet Arginine, nucleotide, fish oil Shorter stay, fewer infections Bower Critical Care Medicine. 23:436, 1995

24. Parenteral Nutrition Immunosuppressive IF... Poorly administered Hyperglycemia No nucleotides No arginine No taurine Excessive fats

25. Overfeeding with parenteral diets Carbohydrate: hyperglycemia, hypercarbia, fatty liver Lipids: hypertriglyceridemia, hypoxia, infection Protein: azotemia

26. Conclusions Nutrition is a powerful determinate of patient outcome The proper provision of nutrition is a component of basic patient care Nutrition is a precise and potentially very hazardous form of intervention