Nutrition

1. Nutrition Basic Science Lecture Series Marcelyn Coley

2. Objectives Assessing nutritional status Nutritional Requirements Calorie Requirements Starvation Enteral Nutrition Parenteral Refeeding syndrome

3. Why nutrition is important Pre-op unintentional weight loss (10%) Increased infection Longer hospital stay Increased mortality Post-Op Decreased wound healing Impaired immune function Loss of muscle function/vent issues

4. Assessment of Nutritional Status HISTORY AND PHYSICAL!! - The best combination of sensitivity and specificity (when compared to other means of nutritional assessment) (when compared to other means of nutritional assessment)

5. Assessment of Nutritional Status Anthropometric Biochemical Clinical Dietary intake A-A variety of techniques used to assess body fuel depots or body composition, i.e. height and weight. Skeletal muscle mass (somatic muscle protein status)—uses mid-arm circumference. More useful in population studies and less reliable for an individual nutritional assessment. B-plasma transport proteins reflect internal or visceral protein status. Nitrogen balance – clinical standard for nitrogen excretion is 24-hr urine collection (UUN)-80-90%...customarily 3-4g added to account for unmeasured losses Positive=net synthesis vs. negative=net loss A-A variety of techniques used to assess body fuel depots or body composition, i.e. height and weight. Skeletal muscle mass (somatic muscle protein status)—uses mid-arm circumference. More useful in population studies and less reliable for an individual nutritional assessment. B-plasma transport proteins reflect internal or visceral protein status. Nitrogen balance – clinical standard for nitrogen excretion is 24-hr urine collection (UUN)-80-90%...customarily 3-4g added to account for unmeasured losses Positive=net synthesis vs. negative=net loss

6. Assessment of Nutritional Status Anthropometric Body Mass Index (BMI), waist circumference, skin fold thickness, mid-arm muscle circumference, and waist-hip ratio A-A variety of techniques used to assess body fuel depots or body composition, i.e. height and weight. Skeletal muscle mass (somatic muscle protein status)—uses mid-arm circumference. More useful in population studies and less reliable for an individual nutritional assessment. B-plasma transport proteins reflect internal or visceral protein status. Nitrogen balance – clinical standard for nitrogen excretion is 24-hr urine collection (UUN)-80-90%...customarily 3-4g added to account for unmeasured losses Positive=net synthesis vs. negative=net loss A-A variety of techniques used to assess body fuel depots or body composition, i.e. height and weight. Skeletal muscle mass (somatic muscle protein status)—uses mid-arm circumference. More useful in population studies and less reliable for an individual nutritional assessment. B-plasma transport proteins reflect internal or visceral protein status. Nitrogen balance – clinical standard for nitrogen excretion is 24-hr urine collection (UUN)-80-90%...customarily 3-4g added to account for unmeasured losses Positive=net synthesis vs. negative=net loss

7. Anthropometric Harris Benedict Equation: BEE (men) = 66.47 + 13.75 (W) + 5.0 (H) - 6.76(A) kcal/d BEE (women) = 655.1 + 9.56 (W) + 1.85 (H) – 4.68 (A) kcal/d Calculates Basal energy expenditure or Resting metabolic expenditure using weight, height, age or gender Calculates Basal energy expenditure or Resting metabolic expenditure using weight, height, age or gender

8. Biochemical Biochemical Creatinine excretion, albumin, prealbumin, total lymphocyte count, transferrin

9. Biochemical

10. Assessment of nutritional status Clinical wt loss, appearance Dietary intake diminished (i.e. severe restricted diets, anorexia nervosa, depression)

11. Calorie requirements Resting 70 kg male: 1450 kcal/day Post-operative: 1700 kcal/day Sepsis, head trauma, pancreatitis: 2400 kcal/day Burns (depends on size): 3000 kcal/day

12. A 75 yo patient s/p Whipple complicated by stroke and anastomotic leak, has failed 2 extubation attempts. One reason that could explain this is a respiratory quotient of: 0.66 0.7 0.8 0.9 1.1

13. A 75 yo patient s/p Whipple complicated by stroke and anastomotic leak, has failed 2 extubation attempts. One reason that could explain this is a respiratory quotient of: 0.66 0.7 0.8 0.9 1.1

14. Indirect Calorimetry Respiratory Quotient (RQ) ratio of CO2 produced:O2 consumed RQ >1.0 = lipogenesis overfeeding RQ <0.7 = ketosis and fat oxidation starvation Pure protein = 0.7 Pure fat = 0.8 Pure carbohydrate metabolism =1.0 Another estimate of energy expenditure…Uses a metabolic cart that analyzes CO2 and Or **>1 can have CO2 build up, ventilator problems Labor intensive and may lead to over estimation of caloric requirements of Energy Expenditure Direct Calorimetry Direct calorimetry measures the heat production of an individual, in calories, when placed in an insulated chamber where the heat is transferred to surrounding water. This is a very accurate method of measuring energy expenditure. Indirect Calorimetry Indirect calorimetry measures respiratory gas exchange from which energy expenditure can be estimated. Oxygen consumption (VO2) and carbon dioxide (CO2) production occur during the oxidation of carbohydrate, protein, and fat. Heat production can be calculated from a measurement of VO2 and/or CO2. Doubly-Labeled Water Doubly-labeled water contains isotopes of oxygen and of hydrogen. The technique involves the consumption by the patient of the doubly-labeled water then the measurement of the amount of isotope in the person after a washout period of 7- 14 days. Most of the hydrogen and oxygen isotopes are lost through excretion and evaporation, but some of the oxygen isotope equilibrates with carbon dioxide and is expired in air. The amount of CO2 produced can be used to figure heat production. Heart-Rate Monitoring Measurement of heart rate can be used to estimate energy expenditure because there is a strong relationship between heart rate and oxygen consumption during activity. The relationship differs depending on whether a person is at rest or active. The relationship is calibrated for each individual. Another estimate of energy expenditure…Uses a metabolic cart that analyzes CO2 and Or **>1 can have CO2 build up, ventilator problems Labor intensive and may lead to over estimation of caloric requirements of Energy Expenditure Direct Calorimetry Direct calorimetry measures the heat production of an individual, in calories, when placed in an insulated chamber where the heat is transferred to surrounding water. This is a very accurate method of measuring energy expenditure. Indirect Calorimetry Indirect calorimetry measures respiratory gas exchange from which energy expenditure can be estimated. Oxygen consumption (VO2) and carbon dioxide (CO2) production occur during the oxidation of carbohydrate, protein, and fat. Heat production can be calculated from a measurement of VO2 and/or CO2. Doubly-Labeled Water Doubly-labeled water contains isotopes of oxygen and of hydrogen. The technique involves the consumption by the patient of the doubly-labeled water then the measurement of the amount of isotope in the person after a washout period of 7- 14 days. Most of the hydrogen and oxygen isotopes are lost through excretion and evaporation, but some of the oxygen isotope equilibrates with carbon dioxide and is expired in air. The amount of CO2 produced can be used to figure heat production. Heart-Rate Monitoring Measurement of heart rate can be used to estimate energy expenditure because there is a strong relationship between heart rate and oxygen consumption during activity. The relationship differs depending on whether a person is at rest or active. The relationship is calibrated for each individual.

15. Indirect Calorimetry Nitrogen balance N(intake) – N(excrection) Urinary Urea Nitrogen 6.25 g protein contains 1 g of nitrogen Positive N balance = anabolic Negative N balance = catabolic (Protein/6.25) – (24H urine nitrogen + 4g) Healthy, 70-kg man ? 250 g/day Urinary nitrogen excretion is proportional to resting energy expenditure Clinical standard is Urinary Urea Nitrogen excretion (UUN) Urinary nitrogen excretion is proportional to resting energy expenditure Clinical standard is Urinary Urea Nitrogen excretion (UUN)

16. Protein Requirement Normal, active person 0.8-1.0 g/kg/day Starvation <1g /kg/day Burns or sepsis 2.0-2.5 g/kg/day Hepatic failure – limit protein 40-50g/day Nonprotein calories significantly enhances efficiency of protein use Recall 24-hr urine N provides most accurate and individualized estimate of nitrogen (protein) needs 150-200 g glucose daily (basis for 3L/day of IV 5% dextrose solutions) 1.Nonprotein calories supply energy, allowing proteins to be used for synthetic purposes vs. being oxidizedRecall 24-hr urine N provides most accurate and individualized estimate of nitrogen (protein) needs 150-200 g glucose daily (basis for 3L/day of IV 5% dextrose solutions) 1.Nonprotein calories supply energy, allowing proteins to be used for synthetic purposes vs. being oxidized

17. Glucose is the primary fuel source for all the following tissues except Renal medulla Brain tissue WBCs RBCs Peripheral nerves Heart

18. Glucose is the primary fuel source for all the following tissues except Renal medulla Brain tissue WBCs RBCs Peripheral nerves Heart

19. The primary source for glucose in early starvation (1week) comes from Proteins in skeletal muscle Ketone bodies Free fatty acids Glycogenolysis Lipolysis / Acetyl CoA

20. The primary source for glucose in early starvation (1week) comes from Proteins in skeletal muscle Ketone bodies Free fatty acids Glycogenolysis Lipolysis / Acetyl CoA

21. Starvation Insulin decreases? mobilized fat, carbs, protein Early starvation (48-72 h) – liver glycogen stores are depleted Day 7 – hydrolysis of skeletal muscle protein and uses amino acids as source of glucose Prolonged starvation – fat metabolism with production of ketone bodies During 7 days of starvation, as much as 5% total body intracellular protein may be lost. Prolonged starvation – brain gets the majority of energy from ketonesDuring 7 days of starvation, as much as 5% total body intracellular protein may be lost. Prolonged starvation – brain gets the majority of energy from ketones

22. Nutrition Goals Positive nitrogen balance Repletion of diminished physical and chemical parameters

23. Nutritional Support To prevent or reverse the catabolic effects of disease or injury

24. Enteral Nutrition When gut is working, use it -avoid bacterial translocation Preferred over parental Reduced costs Less associated risks of IV route Studies have shown reduced infection complication and APP production -Bacterial overgrowth and increase permeability due to starved enterocytes Collectively , healthy patients undergoing uncomplicated surgery can tolerate 10 days do partial starvation( IVF only) before any significant protein catabolism occurs Where as earlier intervention is likely with poorer pre-operative status -Bacterial overgrowth and increase permeability due to starved enterocytes Collectively , healthy patients undergoing uncomplicated surgery can tolerate 10 days do partial starvation( IVF only) before any significant protein catabolism occurs Where as earlier intervention is likely with poorer pre-operative status

25. Indications Prolonged inadequate intake of nutrients NPO >5 days, anorexia, cancer, AIDS-wasting Sustained inability to eat Dysphagia, pulmonary failure Increased metabolic requirements Burns, trauma, brain injury, sepsis

26. How should it be given

27. What to give Enteral Formulations Polymeric – High-residue, viscosity, and osmolarity Elemental – low-residue, simple chemically (standard first-line formulas in stable patients) Modular – single, or a few macronutrients Initiated at 1 kcal/mL 1. Intact macronutrients (i.e. blended whole foods) 2. Enhanced proportions of BCAA, glutamate, arginine, dipeptides, tripeptides and short polypeptides. Good for patients with only absorptive capicity, no digestive capacity, eg. Short bowel syndrome 3. Eg in Diabetics whose hyperglycemic with routine formulations (reducing carbs)1. Intact macronutrients (i.e. blended whole foods) 2. Enhanced proportions of BCAA, glutamate, arginine, dipeptides, tripeptides and short polypeptides. Good for patients with only absorptive capicity, no digestive capacity, eg. Short bowel syndrome 3. Eg in Diabetics whose hyperglycemic with routine formulations (reducing carbs)

28. Enteral Nutrition COMPLICATIONS Mechanical Aspiration, Reflux, Depressed cough, Esophageal erosions, inadvertent feeding into airway/peritoneum GI Function Diarrhea, malabsorption, abdominal cramping, N/V, distention Metabolic Prerenal azotemia, fluid/electrolyte imbalances, hyperglycemia, NKHC, essential fatty acid deficiency

29. Parenteral Nutrition Continuous infusion of hyperosmolar solution containing carbohydrates, proteins, fat, and other nutrients through an indwelling catheter Central “TPN,” or total parenteral nutrition dextrose-based “PPN,” or peripheral parenteral lipid-based

30. Parenteral Nutrition Indicated… When GI tract feeding not possible Supplementing inadequate PO intake

31. Parenteral Nutrition TPN 15 to 25% dextrose Requires large diameter veins PPN Low osmolarity - 5 to 10% dextrose, 3% protein Typically used <2weeks PPN can use small diameter b/c of low osmolarityPPN can use small diameter b/c of low osmolarity

32. Parental Nutrition COMPLICATIONS: Sepsis Early sign: glucose intolerance +/- fever Pneumothorax, hemothorax Emboli Subclavian artery injury Intestinal mucosa atrophy, bacterial overgrowth, impaired gut immunity Reduced IgA production Reduced IgA production

33. Glutamine A nonessential amino acid Most abundant in the body Accounts for 1/3 AA released from muscle during stress Precursor for glutathione, a major intracellular antioxidant During stress states becomes provisionally essential in catabolic states Primary fuel for rapidly proliferating tissues (enterocytes, colonocytes, fibroblasts, wbcs) PicturePrimary fuel for rapidly proliferating tissues (enterocytes, colonocytes, fibroblasts, wbcs) Picture

34. Arginine Depleted in sepsis by making nitric oxide Protein synthesis Immune function ?? enhances T cell responsiveness Stimulates growth hormone and insulin activity

35. Long Chain Triglycerides Safe to administer Calorically dense Good if carbs are restricted Bad if inflammatory disorder because prostaglandin precursor

36. Medium-Chain Triglycerides ?? Cleared rapidly ?? More soluble ?? Improved nitrogen balance ?? Good for inflammatory disorders ?? Neurotoxic in cirrhotics

37. Omega-3 Fatty Acids ”Cure all” – CAD, HTN, OA, inflammatory/autoimmune, cancer It may lead to more beneficial inflammatory mediators Help ESLD mount inflammatory response

38. Essential Fatty Acids Linoleic Acid and a-Linoleic Acid Precursors to arachidonic acid and eicosapenaenoic acid and docosahexanoic acid Precursors to prostaglandins, thromboxanes and leukotrienes Deficiency – skin changes, alopecia

39. Vitamin Deficiencies Vit A - poor healing, skin keratosis, night blindness Vit D - osteomalacia Vit E - dystrophic changes of retina Vit K – coagulopathy Thiamine – (beri beri) lactic acidosis, altered mental status, DI, hyperbilirubinemia, thrombocytopenia Zinc - poor wound healing, impaired immunity Biotin - alopecia, neuritis, dermatitis Selenium - cardiomyopathy, hair loss, weakness Essential fatty acids - scaly dermatitis Vitamin K is not part of any commercially prepared vitamin solution- should be supplemented weeklyVitamin K is not part of any commercially prepared vitamin solution- should be supplemented weekly

40. Refeeding Syndrome Occurs when feeding after prolonged starvation/malnutrition ? low K, Mg, and PO4 Cardiac dysfunction and fluid shifts Prevent by starting at low rate (10-15 kcal/d

41. BRIEF ABSITE REVIEW

42. Branched-chain amino acids are Useful in ESRD Useful in ESLD Useful in pts with COPD

43. Branched-chain amino acids Leucine, isoleucine, valine Only amino acids that do not require metabolization by liver They can also be oxidized by muscle May be used for patients with liver failure

44. ABSITE REVIEW ______g protein has 1 g of nitrogen. ______ N balance = anabolic ______ N balance = catabolic (Protein ÷ 6.25) – (24H urine nitrogen + 4 g) Caloric needs: 25 kcal/kg/day

45. ABSITE REVIEW 6.25 g protein has 1 g of nitrogen. Positive N balance = anabolic Negative N balance = catabolic (Protein ÷ 6.25) – (24H urine nitrogen + 4 g) Caloric needs: 25 kcal/kg/day

46. ABSITE REVIEW RQ > 1 = RQ < 0.7 = Pure fat = Pure protein = Pure carbohydrate =

47. ABSITE REVIEW RQ > 1 = lipogenesis RQ < 0.7 = ketosis and fat oxidation Pure fat = 0.7 Pure protein = 0.8 Pure carbohydrate = 1.0