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Nutritiona therapy in trauma patients M. Safarian, MD PhD.

Pathophysiology of Trauma Definition: any sudden physical damage to the body Mostly occurs in young patients Little or no protein-depletion

واکنش هيپرمتابوليک سپتي سمي استرس تروما سوختگي جراحي Ebb phase شوک Flow phase پاسخ هورموني پروتئينهاي فاز حاد پاسخ ايمني افزايش اوت پوت قلبي، افزايش مصرف اکسيژن افزايش دماي بدن افزايش کاتابوليسم پروتئين افزايش متابوليسم پايه Ebb phase شوک هيپوولمي کاهش دماي بدن کاهش مصرف اکسيژن

Metabolic Response to Trauma Time Energy Expenditure Ebb Phase Flow Phase Trauma causes major alterations in energy and protein metabolism. The response to trauma can be divided into the ebb phase and the flow phase. The ebb phase occurs immediately after trauma and lasts from 24-48 hours followed by the flow phase. After this, comes the anabolism phase and finally, the fatty-replacement phase. Cuthbertson DP, et al. Adv Clin Chem 1969;12:1-55. Cutherbertson DP, et al. Adv Clin Chem 1969;12:1-55

Metabolic Response to Trauma: Ebb Phase Characterized by hypovolemic shock Priority is to maintain life/homeostasis  Cardiac output  Oxygen consumption  Blood pressure  Tissue perfusion  Body temperature  Metabolic rate The ebb phase is characterized by hypovolemic shock. Cardiac output, oxygen consumption and blood pressure all decrease, thereby reducing tissue perfusion. These mechanisms are usually associated with hemorrhage. Body temperature drops. The reduction in metabolic rate may be a protective mechanism during this period of hemodynamic instability. Cuthbertson DP, et al. Adv Clin Chem 1969;12:1-55 Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. Philadelphia, PA: WB Saunders; 1997.

Metabolic Response to Trauma: Flow Phase  Catecholamines  Glucocorticoids  Glucagon Release of cytokines, lipid mediators Acute phase protein production As blood volume is stabilized, the ebb phase is replaced by the flow phase. The flow phase consists of two successive responses: acute and adaptive. Catabolism predominates the acute flow phase. Catabolic stress hormones (glucocorticoids, glucagon, and catecholamines) increase. This hypermetabolism is mediated by an increase in circulating levels of counter-regulatory hormones and other inflammatory mediators, such as cytokines and lipid mediators. These hormonal conditions favor muscle tissue catabolism to provide amino acids for gluconeogenesis and synthesis of hepatic proteins, such as acute phase proteins. Cuthbertson DP, et al. Adv Clin Chem 1969, 12: 1-55 Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. Philadelphia, PA: WB Saunders; 1997.

Metabolic Response to Trauma Fatty Acids Glucose Amino Acids Fatty Deposits Liver & Muscle (glycogen) Muscle (amino acids) Endocrine Response Endocrine response in the form of increased catecholamines, glucocorticoids and glycogen, leads to mobilization of tissue energy reserves. These calorie sources include fatty acids and glycerol from lipid reserves, glucose from hepatic glycogen (muscle glycogen can only provide glucose for the involved muscle) and gluconeogenic precursors (eg, amino acids) from muscle.

Metabolic Response to Trauma 28 24 20 16 12 8 4 Nitrogen Excretion (g/day) This slide illustrates nitrogen losses in relation to trauma. With respect to protein, the greater the trauma, the greater the effect on the nitrogen balance. Similar to metabolic rate, patients experience nitrogen losses according to the severity and duration of the trauma. The normal range is indicated by the shaded area. The amount of protein requirement relative to calories increases in patients with metabolic stress. Long CL, et al. JPEN 1979;3:452-456. 10 20 30 40 Days Long CL, et al. JPEN 1979;3:452-456

Severity of Trauma: Effects on Nitrogen Losses and Metabolic Rate Basal Metabolic Rate Cirugía mayor Cirug í a electiva Infecci ó n Sepsis grave Quemadura moderada a grave Nitrogen Loss in Urine Major Surgery Elective Infection Severe Moderate to Severe Burn This graph illustrates that severity of injury correlates to increasing urinary nitrogen loss and increasing energy needs. Elective surgery being least traumatic and the lowest nitrogen loss in urine, whereas burn results in an increase in basal metabolic rate and urinary loss of nitrogen. Adapted from Long CL, et al. JPEN 1979;3:452-456. Adapted from Long CL, et al. JPEN 1979;3:452-456

Cardio vascular Response to Trauma First : increase heart rate and total peripheral vascular resistance. Blood loss of one third: fall in blood pressure and bradycardia syncope. Blood loss of > 44% : tachycardia Compromised blood supply in the gut: bacterial translocation

اصلاح دريافت پروتئين وميکرو نوترينتها Inpatient management اصلاح آب و الکتروليتها کاهش کاتابوليسم تداخل تغذيه اي اصلاح دريافت پروتئين وميکرو نوترينتها تعيين روش تغذيه

Inpatient management Electrolyte and volume correction Hydrodynamic control Determine the type of nutrition support Determine nutritional demand

Timing and Route of Feeding Timing of feeding: within 24-48 hrs Route of feeding: EN is preferred to PN Stomach is preferred to small bowel Small bowel is preferred if : flail chest, spinal cord injury, severe pelvic fracture, major soft tissue injury or closed head injury.

Timing and Route of Feeding Total enteral nutrition (TEN) Prevent gut mucosa atrophy Preserve gut flora Better ultilization of nutrients Reduce stress response Maintain immunocompetence

Timing and Route of Feeding Contraindication Full-blown shock Sepsis and incomplete resuscitation: reduced splanchnic blood flow → non-occlusive bowel necrosis

Determining Calorie Requirements Indirect calorimetry Harris-Benedict x stress factor x activity factor 25-30 kcal/kg body weight/day There are a wide variety of methods for estimating energy requirements. Common methods include indirect calorimetry and the Harris-Benedict Equation. Indirect calorimetry is based on calculating heat production by measuring oxygen consumed and carbon dioxide produced, through analysis of exhaled gas or use of pulmonary catheters. The Harris-Benedict Equation calculates basal energy requirements for healthy people, but has also been applied to sick patients through the use of correction factors for stress and activity. The simplest estimate of adequate energy intake for patients in metabolic stress is the “rule of thumb” of 25-30 kcal/kg body weight per day.

Determining Calorie Requirements Using harris benedict to calculate REE: Males = 66.5 + (13.5 W) + (5H) - (6.8A) Females =655 + (9.6W) + (1.8H) - (4.7A) Error :7-24 % more than real needs.

Determining Calorie Requirements Injury Minor surgery Long bone fracture Cancer Peritonitis/sepsis Severe infection/multiple trauma Multi-organ failure syndrome Burns Stress Factor 1.00 – 1.10 1.15 – 1.30 1.10 – 1.30 1.20 – 1.40 1.20 – 2.00 When the Harris-Benedict Equation is used to calculate energy requirements, estimated basal energy expenditure is multiplied by a stress factor. As shown in this slide, the stress factor for a long bone fracture is 1.15-1.30, resulting in a metabolic rate increase of 15%-30%. Burns have a greater impact on energy requirements, increasing basal energy expenditure by 20%-100%. In addition, activity factor of 1.2 or 1.3 must be multiplied to determine the energy requirement. ADA: Manual of Clinical Dietetics. 5th ed. Chicago: American Dietetic Association; 1996. Long CL, et al. JPEN 1979;3:452-456. Activity Confined to bed Out of bed Activity Factor 1.2 1.3

Metabolic Response to Overfeeding Hyperglycemia Hypertriglyceridemia Hypercapnia Fatty liver Hypophosphatemia, hypomagnesemia, hypokalemia Trauma or critically ill patients should not be overfed. Alterations in serum glucose and lipid levels, development of fatty liver, and electrolyte shifts have been associated with overfeeding. Barton RG. Nutr Clin Pract 1994;9:127-139. Barton RG. Nutr Clin Pract 1994;9:127-139

Metabolic Response to Overfeeding Over feeding : increase in TEN (thermic effect of nutrition) up to 30% & affect cardio vascular & pulmonary system. TEN is depends on : substrate and the rate The largest is for protein : 20-30% Moderate increase by CHO: 6-8% Minimum by fats: LCT< MCT 2-3% From blue book page 446 Barton RG. Nutr Clin Pract 1994;9:127-139.

Macronutrient needs during Stress Carbohydrate At least 100 g/day needed to prevent ketosis Carbohydrate intake during stress should be between 30%-40% of total calories Glucose intake should not exceed 5 mg/kg/min Delivery of appropriate substrates or macronutients is essential. Patients require at least 100g of glucose per day during metabolic stress to prevent ketosis. During hypermetabolic stress, a carbohydrate level of 30%-40% of total calories is recommended. Glucose intake should not exceed 5 mg/kg/min. Barton RG. Nutr Clin Pract 1994;9:127-139. ASPEN Board of Directors. JPEN 2002;26 Suppl 1:22SA.

Macronutrient needs during Stress Fat Provide 20%-35% of total calories Maximum recommendation for intravenous lipid infusion: 1.0 -1.5 g/kg/day Monitor triglyceride level to ensure adequate lipid clearance Dietary fat should provide between 20-35% of total calories. Maximum recommended infusion rate when administering intravenous lipids is 1.0-1.5 g/kg/day. Serum triglyceride levels in stressed patients should be monitored to ensure adequate lipid clearance. Barton RG. Nutr Clin Pract 1994;9:127-139. ASPEN Board of Directors. JPEN 2002;26 Suppl 1:22SA

Macronutrient needs during Stress Protein: Requirements range from 1.2-2.0 g/kg/day during stress (all pnt losses should be fully replaced) Comprise 20%-30% of total calories during stress. Protein requirements increase during metabolic stress and are estimated at between 1.2-2.0 g/kg/day, or approximately 20% to 30% of the total calorie intake during stress. Barton RG. Nutr Clin Pract 1994;9:127-139. ASPEN Board of Directors. JPEN 2002;26 Suppl 1:22SA

With resolving stress, the energy requirements remain the same but the protein needs decrease to 1.2 g/kg

Macronutrient needs during Stress Urine urea nitrogen (UUN): to evaluate degree of hyper metabolism (stress level) Urine urea (g/d) Stress level 0- 5 Normometabolism (No stress) 5-10 Mild hyper cat (SL one) 10- 15 Moderate hyper cat(SL two) >15 severe hyper cat(SL three)

Macronutrient needs during Stress Stress Level Calorie:Nitrogen Ratio Percent Potein / Total Calories Protein / kg Body Weight No Stress Moderate Stress Severe Stress > 150:1 150-100:1 < 100:1 < 15% protein 15-20% protein > 20% protein Calorie-to-nitrogen ratios can be used to prevent lean body mass from being utilized as a source of energy. Therefore, in the non-stressed patient, less protein is necessary to maintain muscle as compared to the severely stressed patient. Nitrogen balance can be affected by the biological value of the protein as well as by growth, caloric balance, sepsis, surgery, activity (bed rest and lack of muscle use can promote nitrogen excretion), and by renal function. 0.8 g/kg/day 1.0-1.2 g/kg/day 1.5-2.0 g/kg/day

Amino acid supplements

Glutamine in Metabolic Stress Considered “conditionally essential” for critical patients Depleted after trauma Provides fuel for the cells of the immune system and GI tract Helps maintain or restore intestinal mucosal integrity Glutamine is one of the few nutrients included in the category of conditionally-essential amino acids. Glutamine is the body’s most abundant amino acid and is involved in many physiological functions. Plasma glutamine levels decrease drastically following trauma. It has been hypothesized that this drop occurs because glutamine is a preferred substrate for cells of the gastrointestinal cells and white blood cells. Glutamine helps maintain or restore intestinal mucosal integrity. Smith RJ, et al. JPEN 1990;14(4 Suppl):94S-99S. Pastores SM, et al. Nutrition 1994;10:385-390. Calder PC. Clin Nutr 1994;13:2-8. Furst P. Eur J Clin Nutr 1994;48:607-616. Standen J, Bihari D. Curr Opin Clin Nutr Metab Care 2000;3:149-157.

Arginine in Metabolic Stress Provides substrates to immune system Increases nitrogen retention after metabolic stress Improves wound healing in animal models Stimulates secretion of growth hormone and is a precursor for polyamines and nitric oxide Not appropriate for septic or inflammatory patients. Arginine is also considered a conditionally essential amino acid. Barbul and colleagues showed that arginine supplements increased thymus weight in uninjured rats and decreased thymus involution from trauma. (Barbul A, et al. J Surg Res 1980;29:228-235) In studies on humans and animals, arginine supplements increased nitrogen retention and immune function and improved wound healing. Arginine plays other roles that are not well understood; for instance as a scretagogue (growth hormone), precursor for polyamines and nitric oxide. Therefore, one should avoid providing more than 2% of total calories as arginine. Because arginine is considered an immune-enhancing nutrient, it may not be appropriate to feed supplemental arginine to septic or inflammatory patients whose immune system is already stimulated and where addition of arginine supplementation may be detrimental. Barbul A. JPEN 1986; 10: 227-238 It is worth noting that the studies on the use of arginine supplementation were done with patients in the early phase of stress.

Key Vitamins and Minerals Vitamin A Vitamin C B Vitamins Pyridoxine Zinc Vitamin E Folic Acid, Iron, B12 Wound healing and tissue repair Collagen synthesis, wound healing Metabolism, carbohydrate utilization Essential for protein synthesis Wound healing, immune function, protein synthesis Antioxidant Required for synthesis and replacement of red blood cells Micronutrient, trace element, vitamin, and mineral requirements of metabolically stressed patients seem to be elevated above the levels for normal healthy people. There are no specific dosage guidelines for micronutrients and trace elements, but there are plausible theories supporting their increased intake. This slide lists some of these nutrients along with the rationale for their inclusion.

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