Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Nutrition in the Critically Ill patient Dr. Gwynne Jones CCM Surgical Refreshment December 2010 5/23/2017 Are Two Sphyncters Better Than One? • Why feed? • All would agree that food is an important part of a balanced diet. 5/23/2017 Nutrition: Aims • Preserve lean body mass - Protein • Increase protein synthesis or reduce catabolism • Improve/maintain immune-function • Shorten hospital stay 5/23/2017 Nutrition: MEANS • Normal food • Enteral nutrition • Parenteral nutrition 5/23/2017 MALNUTRITION:Caloric need during illness • How many calories would you feed your postoperative patient? 5/23/2017 MALNUTRITION:Caloric need during illness • ? 5/23/2017 MALNUTRITION:Caloric need during illness • Around 25 calories/Kg/day. 5/23/2017 MALNUTRITION:Caloric need during illness • How much protein would you feed your postoperative patient? 5/23/2017 MALNUTRITION:Caloric need during illness • About 1.5 Gm amino acids/Kg/day. 5/23/2017 Nutrition: Definitions • Malnutrition: a disproportion between intake and expenditure of energy and/or essential nutrients • Starvation: first fat, then protein at low speed • Catabolic Disease: fat and protein simultaneously 5/23/2017 NUTRITION: Maintenance of Lean Body Mass • Maintenance of cell membrane function • Cell replication • Protein Synthesis (structural, messengers, etc.) • Muscle contraction (heart, diaphragm, etc.) • Energy generation 5/23/2017 Nutrition: Definitions The Metabolic/Nutritional Syndrome of Critical Illness • • • • • Malnutrition/catabolism Hyperglycemia/Insulin Resistance Impaired Immune Function Abnormal Neuro-endocrine Function Neuro-muscular weakness • Shock from any cause is an Energy Crisis 5/23/2017 Nutrition: Metabolic Profiles Body Composition • Fat free body water in normal state is + 73%. • This may increase to 84% in the hypermetabolic/hypercatabolic patient. • This is associated with a loss of lean body mass (fewer and smaller cells). These are the working parts whose loss accounts for the progressive loss of physiological function. • Smaller cells reduce protein anabolic function. 5/23/2017 Nutrition: Metabolic Profiles Body Composition 100 90 80 70 60 50 40 30 20 10 0 Normal Critical Illness Weight % FAT Extracellular water Body cell mass 1st Qtr 5/23/2017 3rd Qtr Nutrition: Metabolic Profiles Protein Catabolism Protein metabolism Breakdown Synthesis Severity of trauma/sepsis 5/23/2017 Nutrition: Metabolic Profiles Protein Catabolism (N2) losses/ day • Minor surgery: 3-5g • Major surgery: 4-10g • Multiple trauma/burns: 15-20g • Head injury: 5/23/2017 20-25g Nutrition: Metabolic Profiles Protein Catabolism (losses/day) N2/day Protein/day • Minor surgery: 3-5g 18.25-31.25 G • Major surgery: 4-10G 25-62.5 G • Multiple trauma/burns: 15-20G 48-125 G • Head injury: 20-25G 5/23/2017 125-155G Nutrition: Metabolic Profiles Starvation • Nitrogen balance Negative Catabolic Disease Very Negative • Protein turnover to • Muscle catabolism to • Visceral catabolism 5/23/2017 • Urea production or or Nutrition: Metabolic Profiles Starvation • • • • • • Metabolic rate Blood Sugar Insulin level Glucagon level Ketone production Gluconeogenesis • Lipolysis 5/23/2017 Catabolic Disease to or to to to to Triglygeride recycling Nutrition: Metabolic Profiles Starvation Catabolic Disease Metabolic rate to Severely ill patients (septic, major trauma or postoperative) are hypermetabolic and hypercatabolic. Oxygen consumption may be increased 50-100%. This metabolic activity is needed to maintain high cardiac output and ventilatory needs, liver acute phase response and increased immunological activity for healing. 5/23/2017 Nutrition: Metabolic Profiles Starvation • Blood Sugar • Insulin level or Catabolic Disease to to to • Glucagon level This is the stress glucose response. There is insulin resistance both at receptor and postreceptor level. 5/23/2017 Hyperglycemia is immuno-depressive. Nutrition: Metabolic Profiles Starvation Catabolic Disease • Ketone production Although ketone utilisation is still possible, the metabolism is altered such that ketones cannot be synthesised. This reduces fuel efficiency, especially in the brain, increasing energy needs and gluconeogenesis 5/23/2017 Nutrition: Metabolic Profiles Starvation • Lipolysis Catabolic Disease Triglygeride recycling Lipids are well used in the stress state. Lipolysis may be so activated that free fatty acid provision exceeds requirements. 5/23/2017 Nutrition: Metabolic Profiles Starvation • Lipolysis Catabolic Disease Triglygeride recycling Fatty Acids are toxic. They are particularly toxic for the Mitochondria. Fatty Acids are re-esterified often producing hyperlipidemia. This is especially so with high lipid intakes. Hyperlipidemia is immuno-depressive. 5/23/2017 MALNUTRITION: Assessment Anthropometry • Triceps and subscapular skinfold thicknesses provide an index of body fat • Midarm muscle circumference provides a measure of muscle mass • Unfortunately 20%- 30% of healthy controls seem malnourished • Markedly reduced values ( <5th percentile) do have a poor outcome In Our Society these are almost useless 5/23/2017 MALNUTRITION: Assessment Clinical Assessment: Still Best • Subjective Global Assessment (SGA) encompasses: • Nutrient intake (recent dietary intake, weight loss, malabsorbtion) • Effect of malnutrition on organ function and body composition • The patient’s disease and its influence on nutrient requirements – [ Detsky et al. JPEN 1987; 11: 8 ] 5/23/2017 MALNUTRITION: Assessment Immune Competence • Delayed Cutaneous Hypersensitivity (DCH), anergy is a good predictor of poor outcome but is not only a nutritional marker • In-vivo and in-vitro immune analyses are becoming more valuable as are Cytokine levels, but these again are not only influenced by nutrition 5/23/2017 MALNUTRITION: Assessment Muscle Function • Grip strength • Respiratory muscle strength • Response of muscle to electrical stimulation 5/23/2017 MALNUTRITION: Assessment Serum Protein Concentrations • Albumin: best independent predictor (with age) of outcome. However not entirely a marker of nutrition – Prealbumin – Tranferrin – Haptoglobin 5/23/2017 Negative Acute Phase Proteins Nutritional goal in ICU 5/23/2017 Nutrition:Does it work? • • • • • • Is outcome better with feeding? TPN or ENTERAL nutrition? Early feeding? What quantities? What ideal qualities? Immuno-nutrition? 5/23/2017 Nutrition: Metabolic Profiles 100 Weight% Decision Box Increased complications 50 † Starvation Hypermetabolism/ Hypercatabolism 4 5/23/2017 8 12 Weeks † 14 16 MALNUTRITION: Measurement of metabolism in MOF. Bartlett et al. Surgery1982;92:771-779 100 80 Survival % 60 40 20 0 positive 0-10K-ve >10k-ve Cumulative Caloric Balance 5/23/2017 MALNUTRITION: Inflammatory bowel disease; Christie&Hill Grip strength 100 % Normal Value Gastroenterology 1990;99:730-736 Vital capacity 50 0 7 14 5/23/2017 Days 200 Nutrition: Metabolic Profiles Elective abdominal surgery depresses muscle protein B Peterson et al. Br.J.Surg1990; synthesis and increases fatigue 77:796-800 Fatigue 5/23/2017 5 Post-operative day 25 30 Nutrition: Metabolic Profiles • Ebb Phase: acute trauma/ shock period 5/23/2017 Flow Phase: hypermetabolism, hypercatabolism followed by healing Nutrition: Metabolic Profiles • IV carbohydrate or fat totally inhibits gluconeogenesis in normal state. • Provision of all measured caloric needs in stressed patients ( severe sepsis, severe trauma etc.) is able to reduce gluconeogenesis by only 50%. • Thus, even optimal nutrition in the highly stressed cannot stop protein/ lean body wasting, only reduce the rate of this loss. 5/23/2017 Nutrition: Metabolic Profiles • In the normal fasting state, 10% of energy needs are provided by oxidation of amino acids. • This protein oxidation increases to 15% after eating. • Oxidation of amino acids may increase to 25% in the highly stressed patient. • This obligates provision of a high protein intake ( + 1.5 G/Kg/day ) 5/23/2017 MALNUTRITION:Peri-operative TPN The VA TPN study group NEJM1991;325:525-532 395 mal-nourished patients requiring non-urgent laparotomy or thoracotomy TPN 7-10 days pre-op x9 x3 5/23/2017 Non-infectious complications Mild malnourished Severe malnourished Infectious complications Mild malnourished Severe malnourished Control Nutrition: TEN vs TPN Moore et al. Annals of surg 1992;216:172-183 75 patients with severe trauma(ATI>15<40) randomised at laparotomy to receive early feeding (within 72hrs.) with iso-caloric, iso-nitrogenous solutions. Enteral fee via needle catheter jejunostomy using Vivonex. TPN using Freamine. TEN (29pts), TPN (30pts) well matched in age and illness severity. TPN TEN Infectious complications All infections 37% 17% Major sepsis 20% 3% Nutritional/ Albumin metabolic Nitrogen balance +0.1gm -0.3gm 5/23/2017 NUTRITION:Aim of early enteral feeding • • • • • Anabolism/ Reduction of Catabolism Avoidance of Hypermetabolism Nurturing of gut micro-organisms maintenance of gut mucosal health Improving outcome? 5/23/2017 Nutrition:TEN VS TPN Alexander et al. JPEN 1986;10:139 • Wesley Alexander has done innumerable nutritional manipulations in poor, unfortunate flame burned guinea pigs. • Early gut feeding, especially of whole protein reduces hypercatabolism, reduces muscle loss and maintains gut integrity. • His specially formatted EN solution improved outcome in severely burned humans in comparison to usual EN 5/23/2017 NUTRITION: The gut as immune organ • Fasted animals have greater metabolic response to stress than fed animals • Human “volunteers” fed parenterally for one week have a greater metabolic response to endotoxin administration than do enterally fed “volunteers” • Metabolic effect lost if feeding not started within 24 hours 5/23/2017 Nutrition:TEN VS TPN Fong et al. Ann. Surg.1989;210:449-457 • TPN and bowel rest modify metabolic response to endotoxin in humans. • 12 healthy volunteers. Subjected to 7 days of either parenteral or enteral feed of equivalent protein & caloric content. Fasting overnight on day 7 then Am dose of endotoxin. • TPN group much sicker. Stress hormone level 5/23/2017 TNF NUTRITION: Gut hypothesis of multi-organ failure • Gut mucosal ischemia/permeability increase • Gut micro-organisms or their toxins translocate to mesenteric lymph glands or beyond • Macrophage ingestion induces mediator release • Clinical features of “sepsis’ and/or organ dysfunction 5/23/2017 NUTRITION: OXYGEN TRANSPORT Capillary system of Gut Mucosa Gut Mucosa 5/23/2017 Arteriolar Vasoconstriction produces movement of oxygen between arteriole and venule. This leaves the villi tips ischemic. Prolonged shut-down produces necrosis of the tips of the villi. This is a precedent to translocation. NUTRITION: Gut bacteria • Stomach: 102 organisms/ml. • Small Intestine: intermediate numbers increasing distally. • Large Bowel: 109-1016 organisms/ml. 5/23/2017 NUTRITION: Colonisation • Stomach: 102 organisms/ml. • Small Intestine: intermediate numbers increasing distally. • Large Bowel: 109-1016 organisms/ml. • The progressive movement of gut organisms proximally. • This process is impeded by: – Peristalsis – Stomach acidity – Normal gut ecology and food 5/23/2017 NUTRITION: Ileus. • Paralytic Ileus is the transient impairment of bowel motility after abdominal surgery, other injury or severe illness. • Migrating Myoelectric Complex (MMC), spikes occuring on the gut basal electrical rhythm producing a propulsive peristaltic wave. 5/23/2017 NUTRITION: Paralytic Ileus . • Paralytic Ileus: – Most profound in large bowel with loss of mass movement response and gastro-colic reflex. – The stomach is involved to a lesser degree. – The small bowel is involved least. Absorptive function is rarely reduced. 5/23/2017 NUTRITION: Paralytic Ileus – Abnormal distension of a segment of bowel, reflexly inhibits tone and motility of adjacent bowel. – This inhibitory reflex is centred on the spinal cord and effected through sympathetic pathways. – The longer the segment of distended bowel, the less the intraluminal pressure needs to be to trigger the reflex. 5/23/2017 NUTRITION: Paralytic Ileus – Abnormal distension of a segment of bowel, reflexly inhibits tone and motility of adjacent bowel. – This inhibitory reflex is centred on the spinal cord and effected through sympathetic pathways. – The longer the segment of distended bowel, the less the intraluminal pressure needs to be to trigger the reflex. – Bowel dilatation breeds bowel dilatation and indicates the need for decompression. 5/23/2017 NUTRITION: Paralytic Ileus. • Factors Aggravating Paralytic Ileus: – – – – – – Drugs (esp opiates) Diabetes Electrolyte abnormalities Shock Respiratory failure Trauma, sepsis, CNS disease, acidemia 5/23/2017 Are Two Sphyncters Better Than One? Paralytic Ileus. • Factors Aggravating Paralytic Ileus: –Absence of food 5/23/2017 Are Two Sphyncters Better Than One? Paralytic Ileus. • Factors Aggravating Paralytic Ileus: –Absence of food –The propulsive peristaltic activity and its underlying myo-electrical activity need sustained activity to maintain their function. 5/23/2017 NUTRITION:Aim of early enteral feeding Purported benefit of EN Direct provision of energy(glutamine, SCFA) Enterocyte trophic hormone stimulation eg Bombesin, Increased biliary and Urogastrone pancreatic secretion Increased mucosal blood flow Local autonomic stimulation Influence on gut permeability, translocation, metabolism 5/23/2017 When to start enteral nutrition? 5/23/2017 The Gut in Critical Illness • The surface area of the intestinal mucosa is 300M2. • It is adequate for digestion and absorption. • There is a symbiotic relationship between the host and the microbial population built up over aeons. • This allows both host and intestinal flora to live in harmony. 5/23/2017 The Gut in Critical Illness • There is a symbiotic relationship between the host and the microbial population built up over eons. This relationship prevents bacterial invasion and sepsis. • Disturbance of either population is important. • Always remember that there are more bacteria in our gut then human cells in the body. We are the parasites. 5/23/2017 NUTRITION: Gut bacteria • Intestinal bacteria are saprophytic • Starvation changes bacterial population 1. numbers 2. behavior (adherence/ toxin production.) • Some nutrients possess antibacterial effects 5/23/2017 MALNUTRITION: Assessment Clinical Assessment • Effect of malnutrition on organ function and body composition. • You are due to operate on a patient urgently. Would you prefer a patient who is malnourished and has eaten until the day before surgery or a patient who is well nourished but who has been unable to eat for several days? 5/23/2017 MALNUTRITION:Caloric need during illness • Streat et al. (J.Trauma1987;27:262-266) • They measured body composition by in-vivo electron analysis. • Feeding more than 25KCal/Kg/day and 1.5G Amino Acids/Kg/day only succeeded in increasing fat deposition without increase in protein anabolism. 5/23/2017 Enteral or Parenteral?? 5/23/2017 NUTRITION: Arginine • A conditionally essential amino acid. • Levels fall rapidly in acute illness(50%plasma, 30%muscle). Level related strongly with survival. • Substrate for Nitric Oxide generation. 5/23/2017 NUTRITION:Arginine • Supplementation of Arginine has shown: improved nitrogen balance improved wound healing and wound strength • Secretogogue function: growth hormone & Insulin like growth factor Prolactin Insulin & Glucagon 5/23/2017 NUTRITION:Arginine • Substrate for Nitric Oxide 5/23/2017 • Arginine Supplementation is NOT recommended currently. 5/23/2017 NUTRITION:Glutamine • Conditionally essential amino acid • Rapidly falls in acute illness (esp. muscle) • Muscle content important for protein anabolism • Important for normal function of rapidly dividing cells (enterocytes, PMNs) and cells requiring rapid bursts of activity (lymphocytes, macrophages) • 5/23/2017 Important for glutathione system NUTRITION:Glutamine Gln. in FOOD GUT Circulating glutamine pool MUSCLE LYMPHOCYTE MACROPHAGE PMN KIDNEY Gln. Glutamate LIVER 5/23/2017 LUNGS ACID/BASE NH4 NUTRITION:Glutamine The role of Gln. In host defence • It is the most abundant amino acid in the body and in the intracellular free AA pool • Its production by skeletal muscle is dramatically upregulated in times of stress and sepsis • It is the principal carrier of nitrogen between tissues and regulates protein synthesis 5/23/2017 NUTRITION:Glutamine The role of Gln. In host defence • It is an essential precursor of nucleotide synthesis • It serves as a primary substrate for renal ammoniagenesis and arginine synthesis 5/23/2017 NUTRITION:Glutamine The role of Gln. In host defence • Glutamine + Cysteine + Glycine = Glutathione. • This is a major intra-cellular anti-oxidant. 5/23/2017 NUTRITION:Glutamine The role of Gln. In host defence • It is a primary oxidative fuel for rapidly dividing cells (esp. enterocytes and immune cells) • The gut (enterocytes) uses Glutamine as a primary fuel source. • Little Glutamine reaches the plasma from the gut in critically ill patients. 5/23/2017 NUTRITION:Glutamine The role of Gln. In host defence • TPN supplemented with Gln. Maintained intestinal and respiratory tract IgA and mucosal defence in mice • This is achieved through maintenance of Th2 cytokines IL4, IL6 & IL10 5/23/2017 NUTRITION: Human outcome of immune enhancing enteral feeding protocols. Glutamine • enteral nutrition dose ~ 0.3 gm/kg/day • consider in burn/trauma patients • ? other critically ill patients – lack of evidence 5/23/2017 NUTRITION:Omega 3 fatty acid • Omega 6 FFA • Arachidonic acid • 2 series prostaglandins PGI2,TXA2,PGE2 • 4 series leukotrienes-esp LTB4 5/23/2017 • Omega 3 FFA • Eicosapentanoic acid • 3 series prostaglandins PGI3, TXA3, PGE3 • 5 series leukotrienesesp LTB5 NUTRITION:Omega 3 fatty acid • Enteral feeding with a diet supplemented with eicosopentanoic acid, -linolenic acid and anti-oxidants improved outcome in patients with ARDS. (Gadek JE et al. Crit..Care Med.1999;27:1409-1420) 5/23/2017 NUTRITION:Omega 3 fatty acid Mortality100% from severe sepsis/ septic shock 0% 100% Membrane content of Omega 3 PUFA 5/23/2017 NUTRITION: Human outcome of immune enhancing enteral feeding protocols. Fish Oils – Fish Oils Enriched EN improved survival in patients with ARDS/ALI – ? decrease ventilator days and organ failure 5/23/2017 NUTRITION:Nucleotides • In critical illness, the body is unable to make rapidly enough de novo or from the scavenge pathway • Deficiency in animals allows for allograft acceptance • Provision increases foreign graft rejection • NB. Mother’s Milk 5/23/2017 NUTRITION:Vitamins & Minerals • • • • • Anti-Oxidants Selenium Zinc Iron B vitamins 5/23/2017 NUTRITION:Vitamins & Minerals • Tight Sugar Control 5/23/2017 The Gut in Critical Illness The common Mucosal Immune Hypothesis • Peyer’s Patches are mostly in the small intestine. • There is one layer of columnar epithelium, goblet cells and microvillus (M) cells. • M cells present antigen to underlying dendritic cells and macrophages. • These Ag are presented to naïve CD4+ T cells and B cells for development of immune effector cells and cytokines. 5/23/2017 The Gut in Critical Illness • Defence mechanisms of the gut mucosa: – – – – – – mucous coat. Glycocalyx Resident micro-flora (colonisation resistance). Peristalsis. Proteolytic GI sectetions. Innate immune defences (lactoferrin, lysosyme, etc.). –Specific IgA 5/23/2017 The Gut in Critical Illness The common Mucosal Immune Hypothesis Ingested Antigen Inhaled Antigen Genito-urinary Tract Mammary Glands Lamina Propria GALT Peyer’s Patches 5/23/2017 Blood Stream Nasal Passages MAdCAM MLN Specific IgA Thoracic Duct CLN NALT When to start enteral nutrition? Assumptions 5/23/2017 Nutritional goal in ICU Assumptions Timing of Nutritional Support There are 8 RCTs (level 2 studies) of early [within 24-48 hours] enteral nutrition versus delayed EN, PN or oral food intake. Early EN was associated with a trend towards a reduction in infectious complications [RR 0.66. 95% CI 0.36-0.22. p=0.19] (Criticalcarenutrition.com) 5/23/2017 The Impact of Permissive Underfeeding/Targeted Feeding on Mortality and Morbidity in Adult Critically Ill Patients: A Multicentre Randomised Controlled Trial. There are several studies showing low caloric intake to be detrimental and higher caloric intake may be associated with improved outcomes Taylor; 82 head injured patients (CCM 1999) [RCT] ACCEPT (CMAJ) [Cluster RCT] Rubinson; 138 adult ICU pts. (CCM 2004) [Prospective Cohort] Singer; 53 adult ICU pts (Clin Nutr 2004) [RCT] Villet; 48 adult ICU pts. (Clin Nutr. 2005) [Prospective Observational Faisy; 38 adult ICU pts. (Br J Nutr. 2008) [Prospective Observational 5/23/2017 Relationship Between Increased Calories and 60 day Mortality BMI Group P-value Odds 95% Ratio Confidence Limits Overall 0.76 0.61 0.95 0.014 <20 0.52 0.29 0.95 0.033 20-<25 0.62 0.44 0.88 0.007 25-<30 1.05 0.75 1.49 0.768 30-<35 1.04 0.64 1.68 0.889 35-<40 0.36 0.16 0.80 0.012 >=40 0.63 0.32 1.24 0.180 Legend: Odds of 60-day Mortality per 1000 kcals received per day adjusting for nutrition days, BMI, age, admission category, admission diagnosis and APACHE II score. 5/23/2017 RESULTS: 5/23/2017 WHO IS AT RISK? References 5/23/2017