Nutritional Assessment and Support

1. Nutritional AssessmentandSupport

2. Outline • Malnutrition • definition • types • Physiology • fasting • starvation • stress & trauma • Nutritional Assessment • Nutritional Support • timing • enteral vs. parenteral • calculations

3. Nutrition • intake of nutrients to provide energy for… • performance of mechanical work • maintenance of organ/tissue function • heat production • maintenance of metabolic homeostasis • TEE (total energy expenditure) • REE or BEE (fasting resting or basal energy expenditure) ~ 70%(~1 kcal/kg/hr) • activity expenditure ~ 20% avg. but very variable • thermic effect of feeding ~ 10% (intake increases the metabolic rate)

4. Malnutrition • estimated that >50% of hospitalized patients exhibit malnutrition • improving the nutritional status of hospitalized patients… • improves wound healing • decreases infectious complications (in the severely malnourished) • decreases non-septic complications • decreases mortality rate, in some studies • results in the catabolism of energy stores • adipose (oxidation of triglycerides) ~ 13kg in average person • glycogen (glucose) ~ 0.5kg, mostly in muscle • protein (not stored - in use by body) • skeletal muscle ~ 6kg • other protein stores (organs, visceral proteins, nerve tissue) ~ few hundred grams

5. Types of Malnutrition Marasmus • cachexia • chronic calorie malnutrition – relatively balanced diet, but too little for too long • usually the result of a longstanding problem (months) • see wasting of fat, skeletal muscle (weakness) • visceral protein stores less affected Kwashiorkor (West African term – “disease of the displaced child”) • “malnourished African child” (after weaning) with edema and protuberant abdomen • more rapid development and worse prognosis • chronic protein malnutrition (unbalanced diet) or theonset of physiologic stress • fat & skeletal muscle reserves are less depleted (carbohydrates drive insulin) • visceral protein stores & immunity are affected early Marasmic kwashiorkor • combined features – usually what is seen in ICU / ill patients • chronically starved person with stress of illness (hypermetabolic state) • worst prognosis – nutritional support tend to increase fat mass unless the underlying stressors are reversed

6. Early Fasting Human fuelsupply consumption Nerve Liver Muscle75 g/d amino acids glycogen glucose RBCWBC gluconeogenesis lactatepyruvate glycerol Adipose FFA oxidationin mitochondria MuscleHeartKidney fatty acids ketones * lose 5% body protein stores per week

7. Adapted Fasting Human(2 to 6 weeks) fuelsupply consumption Nerve Liver Muscle20 g/d amino acids glucose RBCWBC gluconeogenesis lactatepyruvate glycerol Adipose FFA oxidation in mitochondria MuscleHeartKidney fatty acids ketones

8. Traumatized Human fuelsupply consumption ReparativeProcess Nerve Liver Visceral& Muscle250 g/d amino acids glycogen glucose RBCWBC gluconeogenesis lactatepyruvate glycerol Adipose FFA oxidation in mitochondria MuscleHeartKidney fatty acids ketones

9. Nutritional Assessment

10. Normal Nutrition Calories • US standard diet for 70kg active man contains ~2700 kcal • protein ~325 kcal (81 grams) • fat ~1125 kcal (125 grams) • carbohydrates ~1250 kcal (312 grams) • amount needs to be decreased for inactivity Protein • US standard diet ~80 grams/d (12% of caloric intake) • protein-free diets result in negative nitrogen balance • lose .34 grams protein/kg/d (nitrogen in urine, feces, skin,breath, sputum, etc.) • titrate dietary protein to just keep a positive nitrogen balance • need .38 to .52 grams protein/kg/d (higher estimate b/o inefficiency in utilization) • most use .43 as a minimum and 0.5 - 0.8 gm/kg/d as average • amount needs to be increased for stress (hypercatabolic)

11. Nutritional Assessment • Every patient should prompt three questions • Does malnutrition exist? • Is malnutrition likely to occur? • When and how to correct the situation?

12. Does malnutrition exist? • poor intake • weight loss last 6 months (25% false positive, 33% false negative) • <5% considered mild malnutrition • >20% considered severe malnutrition • weight change in last 2 weeks • allows you to decide whether they can correct the situation on a hospital diet • GI symptoms of anorexia, N/V, diarrhea, malabsorption, obstruction • hypercatabolic pre-admission • infection, sepsis • trauma, burns • major surgery or pulmonary disease • anthropometric changes • loss of SQ fat, muscle wasting, BMI < 14 • functional changes • muscle weakness, respiratory effort • lab studies • albumin, transferrin, prealbumin, RBP, cholesterol, immune function

13. Does malnutrition exist? Subjective Global Assessment Scale (SGA Scale) • graded on 6 features weight change intake GI symptoms functional capacity physiologic stress physical alterations • each feature is rated A = no deficit B = mild deficit C = severe deficit • scored overall A = well nourished = 16% septic complications B = mild to moderate malnutrition = 43% septic complications C = severe malnutrition = 69% septic complications

14. Is Malnutrition Likely to Occur? • poor intake • NPO for more than 3-5 days • GI symptoms of anorexia, N/V, diarrhea, malabsorption, obstruction • hypercatabolic • infection, sepsis • trauma, burns • major surgery or pulmonary disease

15. Simplified Assessment • severe burn or trauma  NS within 24-36 hours • severe physiologic stress and diet will be compromised  NS • NPO for >7 days  NS • use history, wt loss, alb < 3.2, TLC < 1500 and decision chart

16. Nutritional Support

17. Route of Administration • Enteral • more physiologic (doesn’t bypass gut mucosa and liver) • less complicated (supplements, NG tube, PEG, DHT, naso-jejunal tube) • less costly (especially cyclic, intermittent, or bolus feeding) • fewer infectious and other complications • better at preserving gut mucosal integrity and preventing microbial translocation • Parenteral • use only if you cannot use the gut • bowel surgery • bowel obstruction • ileus • not enough bowel / severe malabsorption • no gut access

18. Estimate Needs calories • basal or resting energy expenditure (BEE or REE) men: 66 + (13.7 x kg wt) + (5 x cm ht) – (6.8 x age) women: 665 + (9.6 x kg wt) + (1.7 x cm ht) – (4.7 x age) • activity factor bed rest: +5-20% lightactivity: +50% ambulatory: +30% moderateactivity: +75% • stress factor minorsurgery: +20% major infection: +40-50% skeletaltrauma: +30% severeburn: +50-100% • special cases (unstable sepsis, hypotension) protein • basal 0.5 - 0.8 gm/kg/d • increased for stress

19. Estimate Needs (critically ill)

20. Estimate Needs(Practical Method) • calories per kg/day unstable: 15-20 bed rest: 25 mild stress or activity: 30 moderate s/a: 35 severe s/a: 40 • protein grams per kg/day • no stress: 0.8 • mild stress: 1.0 • dialysis 1.3 • moderate stress: 1.5 • severe stress: 2.0 80 kg patient 2400 kcal 120 grams protein

21. TPN Calculations carbo=D70 lipid=F20 protein=AA10 80 kg patient 2400 kcal 120 grams protein protein=4 kcal/gram AA10=10 grams/dl AA10 =40 kcal/dl AA10 =0.4 kcal/cc protein 120x4=480 kcal 480/0.4=1200 cc 2400-480=1920 kcal fat=9 kcal/gram F20=20 grams/dl F20=180 kcal/dl F20=1.8 kcal/cc lipid 2400x30%=720 kcal 720/1.8=400 cc 1920-720=1200 kcal dextrose=3.45 kcal/gram D70=70 grams/dl D70=241 kcal/dl D70=2.4 kcal/cc carbo 1200/2.4=500 cc *propofol is ~F10 = 1 kcal/cc

22. Monitoring Nutritional Status/Support • correct fluid and electrolyte abnormalities first • watch for refeeding syndrome (fluid retention/CHF, low phos, K, Mg, high glucose) • if serum glucose is hard to control, increase lipid ratio (up to 50-66% of calories), but remember that lipid is less nitrogen preserving than dextrose (below 150 g/d dextrose) • if triglycerides are hard to control, lower the lipid ratio (can be removed for periods) • follow weights daily, prealbumin weekly, and UUN occasionally grams protein intake/6.25 = (grams UUN + 3) grams N deficit x 6.25 = extra grams protein needed