Nutrition

1. Nutrition . . . and the surgical patient

2. Nutrition ENERGY SOURCES • Carbohydrates • Fats • Proteins

3. Nutrition • Carbohydrates • Limited strorage capacity, needed for CNS (glucose) function • Yields 3.4 kcal/gm • Pitfall: too much = lipogenesis and increased CO2 production

4. Nutrition • Fats • Major endogenous fuel source in healthy adults • Yields 9 kcal/gm • Pitfall: too little=essential fatty acid (linoleic acid) deficiency—dermatitis and increased risk of infections

5. Nutrition • Proteins • Needed to maintain anabolic state (match catabolism) • Yields 4 kcal/gm • Pitfall: must adjust in patients with renal and hepatic failure

6. Nutrition Fats Non-protein  Calories Carbohydrates Protein  Calories Proteins

7. Nutrition • Requirements • HEALTHLY 70 kg MALE • Caloric intake=35 kcal/kg/day (max=2500/day) • Protein intake=0.8-1gm/kg/day (max=150gm/day) • Fluid intake=30 ml/kg/day

8. Nutrition • Requirements ? SURGICAL PATIENT ?

9. Nutrition • Special considerations • Stress • Injury or disease • Surgery • Prehospital/presurgical nutrition

10. Nutrition • The surgical patient . . . . • Extraordinary stressors (hypovolemia, bacteremia, medications) • Wound healing • Anabolic state, appropriate vitamins (A, C, Zinc) • Poor nutrition=poor outcomes • For every gm deficit of untreated hypoalbuminemia there is ~ 30% increase in mortality

11. Nutrition HEALTHLY 70 kg MALE Caloric intake 35 kcal/kg/day (max=2500/day) Protein intake 0.8-1gm/kg/day (max=150gm/day) Fluid intake 30 ml/kg/day SURGERY PATIENT Caloric intake *Mild stres, inpatient 20-25 kcal/kg/day *Moderate stress, ICU patient 25-30kcal/kg/day *Severe stress, burn patient 30-40 kcal/kg/day Protein intake 1-1.8gm/kg/day Fluid intake INDIVIDUALIZE

12. Nutrition Non-protein  Calories 30% 70% Protein  Calories Proteins

13. Nutrition • Measures of success • Serum markers • Retinol binding protein, prealbumin, transferrin, albumin

14. Nutrition • Measures of success • Nitrogen balance • Protein ~ 16% nitrogen • Protein intake (gm)/6.25 - (UUN +4)= balance in grams • Metabolic cart (indirect calorimetry) • ICU patient, measure of exchange of O2 and CO2 • Respiratory quotient =1

15. Nutrition • What route to feed? • GUT, GUT, GUT • When to feed? • EARLY, EARLY, EARLY TPN

16. Diet Advancement • Traditional Method • Start clear liquids when signs of bowel function returns • Rationale • Clear liquid diets supply fluid and electrolytes that require minimal digestion and little stimulation of the GI tract • Clear liquids are intended for short-term use due to inadequacy

17. Diet Advancement • Recent Evidence • Liquid diets and slow diet progression may not be warranted!! • Clinical study • Early post-operative feeding with regular diets vs. traditional methods demonstrated no difference in post-operative complications • Emesis, distention, NGT reinsertion, and Length of stay

18. Pitfalls… • For liquid diets, patients must have adequate swallowing functions • Even patients with mild dysphagia often require thickened liquids. • Must be specific in writing liquid diet orders for patients with dysphagia

19. Patients who cannot eat . . . ? • Two types of nutritional support • Enteral • Parenteral

20. Indications for Enteral Nutrition • Malnourished patient expected to be unable to eat adequately for > 5-7 days • Adequately nourished patient expected to be unable to eat > 7-9 days • Following severe trauma or burns

21. Enteral Access Devices • Nasogastric/nasoenteric (temporary) • Gastrostomy (long-term) • Percutaneous endoscopic gastrostomy (PEG) • Open gastrostomy • Jejunostomy • Percutaneous endoscopic jejunostomy (PEJ) • Open jejunostomy • Transgastric Jejunostomy • Percutaneous endoscopic gastro-jejunostomy (G-J) • Open gastro-jejunostomy

22. Feeding Tube Selection • Can the patient be fed into the stomach, or is small bowel access required? • How long will the patient need tube feedings?

23. Gastric vs. Small Bowel Access • “If the stomach empties, use it.” • Indications to consider small bowel access • Gastroparesis/gastric ileus • Abdominal surgery • Significant gastroesophageal reflux • Pancreatitis • Aspiration • Proximal enteric fistula or obstruction

24. Enteral Nutrition Case Study • 78-year-old woman admitted with new CVA • Significant aspiration detected on bedside swallow evaluation, confirmed on modified barium swallow study • Speech language pathologist recommended strict NPO with alternate means of nutrition

25. What is parenteral nutrition? • Parenteral Nutrition • AKA • total parenteral nutrition • TPN • hyperalimentation • Liquid mixture of nutrients given via the blood through a catheter in a vein • Mixture contains all the protein, carbohydrates, fats, vitamins, minerals, and other nutrients needed to maintain nutrition balance

26. Indications for Parenteral Nutrition • Malnourished patient expected to be unable to eat > 5-7 days AND enteral nutrition is contraindicated • Patient failed enteral nutrition trial with appropriate tube placement (post-pyloric) • Severe GI dysfunction is present • Paralytic ileus, mesenteric ischemia, small bowel obstruction, enteric fistula distal to enteral access sites

27. TPN vs. PPN • TPN • High glucose concentration (15%-25% final dextrose concentration) • Provides a hyperosmolar formulation (1300-1800 mOsm/L) • Must be delivered into a large-diameter vein through central line • Peripheral parenteral nutrition (PPN) • Similar nutrient components as TPN, but lower concentration (5%-10% final dextrose concentration) • Osmolarity < 900 mOsm/L (maximum tolerated by a peripheral vein) • Because of lower concentration, large fluid volumes are needed to provide a comparable calorie and protein dose as TPN

28. Parenteral Access Devices • Peripheral venous access • Catheter placed percutaneously into a peripheral vessel • Central venous access (catheter tip in SVC) • Percutaneous jugular, femoral, or subclavian catheter • Implanted ports (surgically placed) • PICC (peripherally inserted central catheter)

29. Complications of Parenteral Feeds • Hepatic steatosis • May occur within 1-2 weeks after starting TPN • May be associated with fatty liver infiltration • Usually is benign, transient, and reversible in patients on short-term TPN—typically resolves in 10-15 days • Limiting fat content and cycle feeds over 12 hours to control steatosis in patients on long-term TPN

30. Parenteral Nutrition Case Study • 55-year-old male admitted with small bowel obstruction • History of complicated cholecystecomy 1 month ago. Since then patient has had poor appetite and 20-pound weight loss • Patient has been NPO for 3 days since admit • Right subclavian central line was placed and plan noted to start TPN since patient is expected to be NPO for at least 1-2 weeks

31. Nutrition • What route to feed? VS TPN

32. Nutrition • What route to feed? TPN TPN

33. Benefits of Enteral Nutrition(Over Parenteral Nutrition) • Cost • Tube feeding cost ~ $10-20 per day • TPN costs up to $1000 or more per day! • Maintains integrity of the gut • Tube feeding preserves intestinal function; it is more physiologic • TPN may be associated with gut atrophy • Less infection • Enteral feeding—very small risk of infection and may prevent bacterial translocation across the gut wall • TPN—high risk/incidence of infection and sepsis

34. Refeeding Syndrome • “The metabolic and physiologic consequences of depletion, repletion, compartmental shifts, and interrelationships of phosphorus, potassium, and magnesium…” • Severe drop in serum electrolyte levels resulting from intracellular electrolyte movement when energy is provided after a period of starvation (usually > 7-10 days) • Sequelae may include • EKG changes, hypotension, arrhythmia, cardiac arrest • Weakness, paralysis • Respiratory depression • Ketoacidosis / metabolic acidosis

35. Refeeding Syndrome • Prevention and Therapy • Correct electrolyte abnormalities before starting nutrition support • Continue to monitor serum electrolytes after nutrition support begins and replete aggressively • Initiate nutrition support at low rate/concentration (~ 50% of estimated needs) and advance to goal slowly in patients who are at high risk

36. Over and Under Feeding • Risks associated with over-feeding • Hyperglycemia • Hepatic dysfunction from fatty infiltration • Respiratory acidosis from increased CO2 production • Difficulty weaning from the ventilator • Risks associated with under-feeding • Depressed ventilatory drive • Decreased respiratory muscle function • Impaired immune function • Increased infection

38. Food for Thought (that is . . . nutrition for your brain) Life is not measured by the number of breaths we take, but by the moments that take our breath away.   TPN

39. References • American Society for Parenteral and Enteral Nutrition. The Science and Practice of Nutrition Support. 2001. • Han-Geurts, I.J, Jeekel,J.,Tilanus H.W, Brouwer,K.J., Randomized clinical trial of patient-controlled versus fixed regimen feeding after elective abdominal surgery. British Journal of Surgery. 2001, Dec;88(12):1578-82 • Jeffery K.M., Harkins B., Cresci, G.A., Marindale, R.G., The clear liquid diet is no longer a necessity in the routine postoperative management of surgical patients. American Journal of Surgery.1996 Mar; 62(3):167-70 • Reissman.P., Teoh, T.A., Cohen S.M., Weiss, E.G., Nogueras, J.J., Wexner, S.D. Is early oral feeding safe after elective colorectal surgery? A prospective randomized trial. Annals of Surgery.1995 July;222(1):73-7. • Ross, R. Micronutrient recommendations for wound healing. Support Line. 2004(4): 4.