Nutritional support in surgical patients

1. Nutritional support in surgical patients

2. Outline of the lecture • Definition of nutritional support • The Role of Nutrients in the Body • Body's endogenous reserve of major nutrients • Classification of Malnutrition and it’s effect in the body • Nutritional Assessment

3. Definition • Nutrients is the constituents of food necessary to sustain normal function of the body • Nutritional support The provision of nutrients orally, enterally or parenterally with therapeutic intent.

4. The Role of Nutrients in the Body • ESSENTIAL NUTRIENTS: • carbohydrates, protein, and fats: • supplying energy and raw materials for metabolism. • Missing just one of these Essential Nutrients puts the body into a state of being malnourished. • ESSENTIAL AMINO ACIDS: • required to make proteins they cannot be created by the body • ESSENTIAL FATTY ACIDS: • Lipids that cannot be created by the body required to make some of the phospholipids.

5. VITAMINS: organic molecules that serve as co-enzymes or parts of co-enzymes and therefore have catalytic functions required in small amounts Water-soluble: B complex, Vitamin C excreted with the urine mild overdoses are harmless fat-soluble:E,D,A,K should be monitored more closely MINERALS: Calcium:bone, nerves and muscles Phosphorus:bone, ATP and nucleic acids Iron:cellular respiration and hemoglobin Iodine:thyroxine Sodium, potassium, and chlorineare important in nerve function Magnesium, manganese, zinc, and cobaltare cofactors built into the structure of certain enzymes

6. Body's endogenous reserve of major nutrients including adipose and somatic muscle tissue CLASSIFICATION OF MALNUTRITION MARASMUS -depletion in the somatic compartment KWASHIORKOR -depletion in the visceral compartment MARASMUS-KWASHIORKOR MIX -depletion in both compartments

7. Malnutrition • Preoperative • Starvation • failure of proper digestion • Postoperative

8. Starvation which may be secondary to: • Poverty and inability to obtain food • Dysphagia • Vomiting • Self neglect, e.g alcoholics and the elderly

9. Conserve energy by decrease in metabolism Initial loss of glycogen (24 hr), body fat, then skeletal protein • Death is due to weakness of diaphragm, pneumonia or other infection; timing depends on size of fat stores

10. Failure of digestion • Pancreatic or biliary disease, e.g. carcinoma, stone • Duodenal or jejunal disease, e.g. fistula, blind loop syndrome

11. Postoperative malnutrition • Usually result of the stress of surgery and is a transient nature • However, it may be as severe with such major operations as • esophagectomy and paralytic ileus

12. What happens during acute stress? • Catabolism of body protein (viscera and skeletal) in order to support gluconeogenesis. • Hormones: glucagons, catecholamine, glucocorticoids … promote fluid retention • Cytokine response: fever, inflammation, increase metabolism. • Skeletal protein is depleted

13. Hypercatabolic states • An increase in metabolic rate and protein catabolism of >25% e.g. • Sever sepsis • Sever trauma as in burns • Sever inflammation as in pancreatitis • Body fat used more gradually • Death is due to weakness of diaphragm, pneumonia or other infection.

14. Manifestations General • Physical and mental exhaustion • Infection, due to immunosuppression • Intolerance to radio- and chemo-therapy Metabolic: • Lowered rates of enzyme synthesis • Impaired oxidative metabolism of drugs by the liver

15. Healing problems: • Wound dehiscence • Leakage from bowel anastomoses • Delayed callus formation • Disordered coagulation

16. Nutritional Assessment • How do we detect malnutrition? • History • Physical examination • Laboratory investigations

17. History • Dietary history • Change in appetite • Significant weight loss within last 3 months • 15% loss of body weight • Compare with ideal weight • Beware the patient with ascites / edema

18. Physical examination • Evidence of muscle wasting • Depletion of subcutaneous fat • Features of Vitamin deficiency • (Glossitis in vit B12 def , hypertrophic gum : scurvy in vit C def, follicular keratosis in vit A def , pellagra in niacin def) • Echymosis and easy bruising • Easy to detect > 15% loss weight

19. Physical examination • Weight for Height comparison • Body Mass Index • Wt (kg) / Ht (M)2. • NORMAL BETWEEN 18.5 – 24.5

20. Physical examination • Anthropometry • triceps skin fold (TSF) by caliper (minimum : • 13 mm in female, 10 mm in male) • mid arm circumference (MAC). • mid arm muscle circumference (MAMC) • (feeding is indicated if less than 23 cm in F and 25 cm in M) • {MAMC = MAC cm – (TSF mm × 0.314)}

21. Lab Investigations • Albumin < 30 mg/dl • Pre-albumin < 12 mg/dl • Transferring < 150 mmol/l • Total lymphocyte count < 1800 /mm3 • Tests reflecting specific nutritional deficits • e.g. prothrombin time

22. Candida skin test • Nitrogen balance studies • urinary creatinine and 3—methylhistidine excretion • total body K and N • 14C--leucine incorporation • Fecal fat test • Schilling test • Hydrogen breath test • D-xylose

23. Assessing Nutritional Status:The SGA • A. History • Weight change <5% = “small”5–10% = “potentially significant” >10% = “definitely significant” • Change in dietary intake • Gastrointestinal symptoms(nausea, vomiting, diarrhea, anorexia) • Functional capacity • Disease and its relation to nutritional requirements • B. Physical • Loss of subcutaneous fat • Muscle wasting • Ankle edema • Sacral edema • Ascites • C. SGA Rating • subjective global assessment • A = Well nourished • B = Moderately malnourished • C = Severely malnourished

24. Thank you

25. NOTES • ESSENTIAL NUTRIENTS • 57% Carbohydrates (sugar, sweets, bread, cakes) • 30% Fats (dairy products, oil) • 13% Protein (eggs, milk, meat, poultry, fish) • Body's endogenous reserve of major nutrients • The Carbohydrates provide energy for 24 hr max • Brain , RBC and kidney relay on Carbohydrates for supplying the energy • After 24 hr the body protein undergo gluconeogenesis to supply energy for the three vital organs • Nutritional Assessment • The must important (practical) steps • History : 10% weight loss in 3-6 months • BMI • Albumin and HGB

26. The Doctor said you may ask to calculate the total calories in MCQs • Calories per gram of:Water = (0 Cal)Protein = (4 Cal)Dietary fiber = (3 Cal)Fat = (9 Cal)Alcohol = (7 Cal)Carbohydrates = (4 Cal