1 / 38

Nutrition

Nutrition. Dr James F Peerless July 2013. Objectives. Introduction to nutrition Assessment of the patient Feeding requirements Macro- & micronutrients Enteral vs. parenteral feeding Refeeding syndrome. Introduction. Nutrition support: enteral or parenteral provision of

niyati
Download Presentation

Nutrition

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nutrition Dr James F Peerless July 2013

  2. Objectives • Introduction to nutrition • Assessment of the patient • Feeding requirements • Macro- & micronutrients • Enteral vs. parenteral feeding • Refeeding syndrome

  3. Introduction • Nutrition support: • enteralor parenteral provision of • calories • protein • electrolytes • vitamins, minerals • trace elements • fluids • Goal of therapy is to supply each substrate in the right quantity necessary to meet the metabolic needs of each patient Total energy Protein Lipids (fat) Carbohydrates Micronutrients

  4. Nutrition • Aims of nutritional support on the ICU: • Provide exogenous substrates to meet macro and micronutrient requirements in dependent patients • Help protect vital visceral organs and attenuate breakdown of skeletal muscle • Reduce net protein catabolism • Contraindications to commencing feed (enteral or parenteral) on ICU: • Able to resume full oral diet within 3 days • Inappropriate for ethical reasons

  5. Nutritional Requirements

  6. Assessment of nutritional status • It is estimated that 60% of patients are malnourished prior to hospital admission • Malnutrition is associated with a poor outcome – increased LoS and incidence of complications in critical care. • Assessment difficult • Anthropometric measurements good for populations • BMI does not reflect acute changes • Biochemical tests have limitations

  7. Subjective Global Assessment History • Weight change (chronic and acute) • Changes in food intake • GI symptoms (N, V, D, anorexia) • Functional impairment Examination • Loss of SC fat (chest, triceps) • Muscle wasting (temporal, deltoid, gluteal) • Oedema • Ascites

  8. Nutritional Requirements • Harris Benedict Equation • For the calculation of BMR (kcal/day) • BMR for a healthy, afebrile individual • ≈25 kcal/kg/day • Also the Schofield Equation • Male BMR = (13.75 ×wgt) + (5 × hgt) – (6.78 × age) + 66 • Female BMR = (9.56 × wgt) + (1.85 × hgt) – (4.68 × age) + 655

  9. Nutritional Requirements • Harris Benedict Equation • For the calculation of BMR (kcal/day) • BMR for a healthy, afebrile individual • ≈25 kcal/kg/day • Fever: 10% for each 1°C above 37°C • Sepsis: 9% (irrespective of T°C) • Surgery: 6% if post trauma or surgery

  10. Critical Illness and Requirements • Acute critical illness • Catabolism > anabolism • CHO are preferred energy source (fat mobilisation is impaired) • Aim of nutritional support to minimise muscle protein breakdown • Acute initial phase of critical illness 20-25kcal/kg/day • Recovery phase • Anabolism > catabolism • Nutritional support provides substrates for: • correction of hypoproteinaemia • Reparation of muscle loss • Replenishes nutritional stores • Recovery/anabolic phase 25-30kcal/kg/day

  11. Nutritional Requirements Macronutrients • Provide energy • Protein: 5.3 kcal/g • Lipid: 9.3 kcal/g • Carbohydrate: 3.75 kcal/g Micronutrients • Required in small amounts to maintain health but do not provide any energy

  12. Protein Requirements • 1.5 g kg-1 day-1 • 6.25 g contains 1 g of nitrogen  ~ 0.20g nitrogen/kg/day. • Nitrogen losses are large in critically ill patients Nitrogen output = urinary urea/mmol/24 hours x 0.033 + obligatory losses + extra renal losses • Obligatory losses • estimated as 2-4g nitrogen/day (skin, hair, faeces etc) • Extra renal losses include: • Pyrexia • Inflammatory bowel disease • GI fistulae • Extensive bed sores • Burn exudates

  13. Protein Requirements in Specific Conditions • Renal failure • Haemofiltration associated with increased protein losses (~10%) • Liver failure • Protein requirements dependent on underlying function of the liver: • Compensated cirrhosis 0.19-0.20gN/kg/day • Decompensated cirrhosis 0.25-0.30gN/kg/day • Post-transplant 0.25-0.30gN/kg/day • Acute (fulminant) liver failure 0.20-0.25gN/kg/day

  14. Lipid Requirements • Lipid • Limit to 40% of calorie intake • Critically ill patients require approximately 0.8-1.0g/kg/day of lipid. • NB: propofol is a lipid source • Each ml contains of 1% propofol contains 0.9kcal and can increase the risk of both fat and total calorie overfeeding and micronutrient deficiency

  15. Carbohydrate Requirements • Carbohydrate • Excess intake above this can result in: • hyperglycaemia • lipid synthesis • increased carbon dioxide production Carbohydrate + O2 = water + CO2 + energy production

  16. Micronutrient Requirements • Vitamins • Organic molecules essential for life; not synthesised by higher organisms • Fat-soluble: A, D, E, K • Water-soluble: C, B complex • Minerals • Single elements essential to life: Ca, P, Mg, Zn, Fe, I • Trace elements • Essential to life, but in minute quantities: Cu, Co, Mn, Ni, Mo, Cr

  17. Micronutrient Requirements • No set levels for micronutrient requirements for the critically ill • aim for the normal recommended daily allowance • Specific disease states • Thiaminedeficiency in alcoholics • Vitamin B12deficiency in patients post gastrectomy or total ilealresection • Zinc losses from pancreatic fistulae • Phosphate, magnesium and potassium deficiencies upon refeeding a malnourished patient • Micronutrient supplementation in patients with renal failure needs to be undertaken cautiously due to risks of toxicity.

  18. Enteral Feeding

  19. Feeds • Standard formulation suitable for most patients • Isotonic • Lactose-free • Protein • Mixture of simple/complex CHO • Long-chain fatty acids • Micronutrients • Pro-biotics • Variety of formulations available: • Concentrated for fluid restriction • Pre-digested for enzyme deficiencies

  20. Enteral Nutrition • Continuous vs bolus • No difference in mortality, infection, ITU LoS • Monitoring • Measurement of gastric residuals to minimise risk of accumulation and aspiration • This is shown to correlate poorly with aspiration, and disrupts absorption. • Consensus towards only measuring residual if clinically indicated.

  21. Complications • Aspiration • Backrest elevation • Post-pyloric feeding • Surgical/percutaneous feeding • Motility agents • Diarrhoea • Dehydration • Metabolic abnormalities • hyperglycemia • micronutrient deficiencies • refeedingsyndrome • Mechanical complications

  22. Parenteral Feeding

  23. Parenteral Nutrition • Contains a carefully formulated mixture of macronutrients, and fluid • Can be used to provide 100% of patient’s requirements • Varying formulations (protein/lipid ratios depending on patient requirement) • Minerals and trace elements are added to the bag by the pharmacy.

  24. Initiation of PN • Deliver via central venous route • High osmotic load poorly tolerated by peripheral veins • <30d  CVC, PICC • >30d  tunneled lines: Groshong, Hickman • Dedicated port • Risk of infection

  25. Monitoring • Strict input/output measurement • Daily electrolytes, until regime fully established • LFTs, and triglycerides once a week

  26. When to Start? • Early provision (<48h) of PN to well-nourished patients does not alter mortality • Early PN in well nourished patients may be associated with increased risk of infection (by 5%), even if EN is contraindicated. • Higher incidence of hypoglycaemia in late PN Koretz RL, Lipman TO, Klein S, American Gastroenterological Association. AGA technical review on parenteral nutrition. Gastroenterology 2001; 121:970. Kerrie et al. Early versus late parenteral nutrition in the adult ICU: feeding the patient or our conscience? J Can Anesth (2012) 59:494–498

  27. Glutamine • Precursor for nucleotide synthesis • Important fuel source for new cells (e.g. GI mucosa) • Therefore helps maintain gut mucosal function, integrity and immune function • Also has anti-oxidant actions which were thought to be useful in critical illness: however, REDOX trial suggests an increase in 28-day mortality. Heyland et al. A Randomized Trial of Glutamine and Antioxidants in Critically Ill Patients. NEJM 368;16 1489-1497

  28. Complications • Bloodstream infection • Metabolic abnormalities • hyperglycemia • serum electrolyte alterations • macro- or micro-nutrient excess or deficiency, refeeding syndrome • Wernicke's encephalopathy • hepatic dysfunction • Problems related to venous access

  29. Refeeding Syndrome

  30. Refeeding Syndrome • Results from rapid changes in fluids and electrolytes • Pathophysiology based on total/partial starvation followed by refeeding • Occurs in up to 35% of ITU patients • Life-threatening, especially if associated with thiamine deficiency Mehanna HM, Moledina J, Travis J. Refeeding syndrome: what it is, and how to prevent and treat it. Br Med J 2008; 336:1495 – 1498.

  31. Refeeding Syndrome • Defined primarily by manifestations of severe hypophosphataemia • Cardiovascular collapse • Respiratory failure • Rhabdomyolysis • Seizures • Delirium • Hypokalaemia • Hypomagnesaemia

  32. Identifying at-risk patients • One or more criteria • BMI below 16 • Unintentional weight loss >15% in 3–6 months • Little or no nutrient intake for more than 10 days • Low potassium, phosphate, magnesium before feeding. • Two or more criteria • BMI below 18.5 • Unintentional weight loss >10% in 3–6 months; • Little or no nutrient intake for more than 5 days; • History of chronic drug (insulin, diuretics, antacids) use or alcohol misuse. NICE CG32: Nutrition Support in Adults; February 2006

  33. Summary

  34. Summary • During critical illness: • Marked catabolic process • Increase in BMR • Relative insulin resistance • Malnutrition associated with impaired immune function and increased morbidity • Early recognition and correction of nutritional status is crucial

  35. ESPEN Guidelines • Patients should be fed because starvation or underfeeding in ICU patients is associated with increased morbidity and mortality • All patients who are not expected to be on normal nutrition within 3 days should receive PN within 24 - 48 hours if EN is contraindicated or not tolerated. Singer et al. ESPEN Guidelines on Parenteral Nutrition: Intensive care. Clinical Nutrition 28 (2009) 387–400

  36. Summary of Daily Requirements • Calories 25 kcal/kg • Protein 0.25 g N2/kg • Glucose 2 g/kg • Fat 2 g/kg • Water 30 mL/kg • Sodium 1.2 mmol/kg • Potassium 0.8 mmol/kg

  37. Reference

  38. Reference • Smith T, Pinnock C, Lin T. Fundamentals of Anaesthesia, 3rd Edition; 2009. Cambridge: Cambridge University Press. • Wellesley H. Nutrition in ICU, 2007. http://www.frca.co.uk/article.aspx?articleid=100979#accessed 26.06.13 • Macdonald K, Page K, Brown L, Bryden D. Parenteral nutrition in critical care. Continuing Education in Anaesthesia, Critical Care & Pain, 2012; 13(1): 1-5 • Campbell Edmondson W. Nutritional support in critical care: an update. Continuing Education in Anaesthesia, Critical Care & Pain, 2007; 7(6): 199-202 • Uptodate.com (accessed 28.06.13) • Nutritional support in critically ill patients: parenteral nutrition • Nutritional support in critically ill patients: enteral nutrition • Nutritional support in critically ill patients: an overview

More Related