Nutrition in the critically ill

1. Nutrition in the critically ill Amie Kershaw Critical Care Dietitian Manchester Royal Infirmary

2. Malnutrition Aims of nutrition support Nutritional requirements Nutrition support Potential complications Developing areas Overview

3. Malnutrition in hospital

4. What is malnutrition? • “Malnutrition is a state of nutrition in which a deficiency or excess (or imbalance) of energy, protein and other nutrients cause measurable adverse effects on tissue/body form (body shape, size and composition) function and clinical outcome.” Elia, (2000)

5. Definition of malnutrition • A body mass index (BMI) <18.5kg/m • Unintentional weight loss >10% in 3 – 6 months • A BMI <20kg/m and unintentional weight loss >5% in 3 – 6 months

6. Why does malnutrition develop? • Impaired intake • Impaired digestion and absorption • Altered nutritional requirements • Excess nutrient losses

7. Many people are malnourished prior to admission to hospital People in hospital are at risk of becoming malnourished or further malnourished Prevalence of malnutrition in hospital has been quoted as 40% (McWhirter & Pennington, 1994) Up to 43% of patients in ICU are malnourished (Giner et al, 1996) Malnutrition

8. Consequences of malnutrition • Weight loss • Weakness and fatigue • Impaired ventilatory drive  DEATH • Depression / apathy • Poor wound healing • Impaired immune function Webb (1999), Garrad (1996)

9. Nutritional Screening – why? Government initiatives + recommendations • 2003 Food, Fluid and Nutritional Care (NHS Quality Improvement, Scotland) • 2002 Nutrition and Catering Framework (Welsh Assembly Government) • 2001 NSF for Older People (DH) • 2001 Essence of Care (DH) + 2006 Nice Guidelines

10. Malnutrition Universal Screening Tool(MUST) • Anticipate/prevent malnutrition • Confirm malnutrition • To facilitate planning of appropriate nutritional support • To act as a method of monitoring progress • Takes into account the past, present and future • Can be used across a variety of settings

11. MUST • To be completed for each patient on admission and rescreen weekly (or more often if indicated) • ACTION to be taken according to the high, medium or low risk score • Completed assessment forms to be kept with patient documentation

12. Nutrition Support

13. Why feed the critically ill? • Provide nutritional substrates to meet protein and energy requirements • Help protect vital organs and reduce break down of skeletal muscle • To provide nutrients needed for repair and healing of wounds and injuries • To maintain gut barrier function • To modulate stress response and improve outcome

14. Nutritional Requirements Energy Calculation of basal metabolic rate with additional factors for: • Stress • Activity • Energy required to metabolise food (diet induced thermogenesis) Protein Typically 0.8 – 1g protein/kg, increased during stress Fluid 30ml/kg for >60yrs and 35ml/kg for < 60yrs

15. Hyperlipidemia (increased fat levels in the blood) Azotemia (increased urea) Hyperglycaemia (high blood sugar levels) Fluid overload Hepatic dysfunction (abnormal liver function tests, fatty deposits in the liver) Excess CO2 production Respiratory compromise Metabolic consequences of overfeeding Klein (1998)

16. Enteral feeding“If the gut works – use it” • Nasogastric (NG) • Nasojejunal (NJ) • Percutaneous Endoscopic Gastrostomy (PEG) • Percutaneous Endoscopic Jejunostomy (PEJ) • Radiologically Inserted Gastrostomy (RIG) • Surgical Gastrostomy • Surgical Jejunostomy (JEJ)

17. Common feeds used on ICU

18. Long term: Inflammatory bowel disease Radiation enteritis Motility disorders Extreme short bowel syndrome Chronic malabsorption Short term: Severe pancreatitis Mucositis post-chemo with intolerance of enteral nutrition Gut failure Prolonged nil by mouth (NBM) post major excisional surgery High output or enterocutaneous fistula Intractable vomiting Malnourished patient unable to establish enteral nutrition Indications for Parenteral Nutrition

19. Complications of Nutrition Support

20. Prokinetics- Gut motility medication Indication for use Possible causes - High gastric aspirates - Medications - Gut failure - Diabetic stasis Prokinetics of choice - Metoclopramide - Erythromycin - Major cause of underfeeding

21. Diarrhoea • Nosocomial (hospital acquired) • Non-infectious causes: • medications • sorbitol, magnesium salt containing • antibiotics – 5 – 30% incidence (McFarland) • feed malabsorption, faecal impaction, low albumin - not major risk factors Fibre in EN - a combination of soluble & insoluble fibre •  colonic blood flow, promote sodium & water retention and therefore may help control diarrhoea

22. Refeeding Syndrome • “Severe fluid and electrolyte shifts and related metabolic complications in malnourished patients undergoing refeeding.” Solomon &Kirby (1990)

23. Refeeding Syndrome During starvation • Insulin concentrations decrease and glucagon levels rise • Glycogen stores rapidly converted to glucose • Gluconeogenesis activated – glucose synthesis from protein and lipid breakdown • Catabolism of fat and muscle  loss of lean body mass, water and minerals

24. Refeeding Syndrome During refeeding • Switch from fat to carbohydrate metabolism • Insulin release stimulated by glucose load •  cellular glucose, phosphorus, potassium and water uptake • Extracellular depletion of phosphate, potassium, magnesium • Clinical symptoms

25. Clinical Symptoms

26. Clinical Symptoms

27. Who is at risk? NICE guidelines (2006) Some risk: • People who have eaten little or nothing for more than 5 days

28. Who is at risk? High risk: • One or more of the following: - BMI < 16kg/m - unintentional weight loss > 15% in last 3 – 6 months - Little or no nutritional intake for >10days - Low levels of potassium, phosphate or magnesium prior to feeding

29. Who is at risk? High risk: • Two or more of the following: - BMI < 18.5kg/m - Unintentional weight loss > 10% in last 3 – 6 months - Little or no nutritional intake for more than 5 days - History of alcohol abuse or drugs: insulin, chemotherapy, antacids or diuretics

30. Managing refeeding syndrome • Consider Pabrinex (high dose thiamine) and balanced multivitamin/mineral supplement • Feed cautiously – 10kcal/kg for first 2 days, 5kcal/kg in extreme cases (dietitian will advise). Increase slowly (over 4 -7 days) • Monitor biochemistry regularly including phosphate, magnesium and potassium correcting low levels as necessary

31. Developments in Nutrition Support

32. Immunonutrition • Potential to modulate the activity of the immune system by interventions with specific nutrients

33. Immunonutrition Nutrients most often studied: • Arginine - can enhance wound healing and improve immune function. Conditionally essential amino acid. • Glutamine – Precursor for rapidly dividing immune cells, thus aiding in immune function.Conditionally essential. • Branched chain amino acid’s – support immune cell functions. • Omega 3 fatty acids – lowers magnitude of inflammatory response, modulate immune response.

34. Immunonutrition Espen guidelines (2006): • Immune modulating formula beneficial in the following patient groups: - upper GI surgery - mild sepsis - trauma • If unable to tolerate <700ml/d immune modulating formula should be stopped. • Not recommended for routine use in ICU patients

35. Immunonutrition Espen Guidelines (2006) • Glutamine should be added to a standard enteral formula in burned and trauma patients • Insufficient data to support enteral glutamine supplementation in surgical or heterogeneous critically ill patients