Nutritional Support of the Injured Patient A health care practice does not usually attend to severely traumatized, burned, or critically ill patients because they are usually hospitalized for extended periods. However these patients, after discharge, or other patients who are less traumatized or ill will find their way for folowup care. Although trauma specialist consider nutritional needs of these patients while they are hospitalized, traditional medicine usually neglects the nutritional needs of these patients as well as the pre and post surgical patient. This is of particular concern in work injuries and is a factor of delayed healing or inability to successfully rehabilitate injured workers to pre injury work status. The purpose of this article is to discuss several nutritional factors that should be addressed in supporting the injured or ill patient: The route of nutritional support The timing (frequency) of nutritional support There are specific nutrient requirements (macronutrients and micronutrients) Damage to organ systems demand specific nutritional support Quality of nutrition (nourishment) is important Monitoring the effectiveness of the nutritional prescription (functional testing) While there is some inconsistency in research data, largely due to biochemical individuality and the nature of the trauma or illness, there are certain general principals that emerge to form a scientific as well as common sense approach to management of patients that have increased nutritional requirements due to trauma or disease. The Nutritional Route Can Influence the Outcome: Enteral (feeding by tube or mouth) vs. parenteral (intravenous, intramuscular, etc.) presents a controversy in the research. Higher protein diets require less intravenous nutritional support. Intravenous feeding increases permeability of the gut to bacterial displacement and thus in abdominal trauma, infection could be a greater risk. Although enteral feeding has far less bacterial sepsis compared with intravenous feeding of the trauma patient there is overriding concern that enteral feeding does not deliver adequate amounts of protein or calories in the trauma patient. This is particularly true of the surgical patient that must interrupt feeding by mouth prior to surgery to avoid gastroporesis (vomiting) or aspiration. Infection is more common in low protein intake, inadequate calorie intake and negative nitrogen balance. Brain injured patients usually have delayed gastric dumping and therefore do better with intravenous feeding rather than enteral feeding in the first 16 days post injury. After that there is not much difference. This includes patients with concussion injuries which are common in sports injuries and motor vehicle accidents. Timing or Frequency of feeding is Important: Traumatized patients have significantly more calorie demands and that demand is important to meet within the first 7 days post injury. There is evidence that there is improved outcome
associated the early feeding (2 hrs) post injury versus delayed feeding. This is not always possible in the some injuries or post surgical patients. It is however important to feed as soon as possible. Although enteral feeding is more physiological and less expensive then intravenous feeding, certain nutrients can not reach pharmaceutical levels if they are not administered by intravenous feeding. Therefore it is preferable to supplement enteral feeding with intravenous or intramuscular feeding to achieve the desired levels of nutrients. It is ideal to graze or have frequent meals rather than eat two or three large meals during the day. The healing process has nothing to do with the cultural traditions of breakfast, lunch, and dinner. There are also factors of Circadian rhythms which also place requirements on frequency and timing of feeding. There are Specific Nutrient Requirements: Diseases and injury alters metabolism. Proper nutritional support is needed to prevent further cellular damage as well as promote repair. Metabolic priorities are also altered as well as changes in metabolic pathways with disease and injury. Adequate calories intake is vital to the injured or ill patient. Resting energy expenditure increases 10 to 60% above normal to support increased metabolic workload: Skeletal trauma increases to above 40% Major burns increases up to 60% Closed head injuries up to 40% Infections increases up to 30% elective surgery up 10% Cancer up to 50% Renal disease without dialysis up to 30% Liver failure up to 50% Chronic obstructive pulmonary disease (COPD) up to 25% GI disease such as Crohn's disease up to 35% Protein intake is vital to the injured or ill patient. If this is not supported there is erosion of the lean body mass and negative nitrogen balance (starvation). If there is loss of 20% body weight there can be immune system dysfunction and 40% loss of weight can be fatal if the weight loss occurs over a short period of time. Protein requirements are increased to accommodate immune system response which must manufacture cells to meet the healing requirements as well as replace damaged cells or replace blood loss. Too much protein or calories can lead to stress on the liver, lungs, and immune system. Pediatric (children) patients have additional demand of growth and maturation which further stresses the protein and caloric demand. It is further important to make adjustments to the feeding, because as wounds heal there is declining energy expenditure and the calorie intake must be appropriately reduced. Calorimetry
is a tool that can monitor the change and is also a gauge of healing. Excess calories to the patient can induce hyperglycemia (high blood sugar), excess CO2 production, fluid electrolyte abnormalities, fat production and fatty liver. Injury or illness causes elevation of the catecholamine and corticosteroid hormones, increased rate for gluconeogenesis as well as elevated glucagon and insulin resistance. This coupled with increased leukocytes and fibroblast in wounds requires increased need for glucose. If these demands are not met, there is accelerated muscle breakdown (proteolysis). Normally there is a demand of about 0.8 grams of protein per kilogram of body weight per day. Disease, infections, or trauma can increase protein requirements to 2 grams per kilogram daily. In other words up more than 2 times of what is the normal intake. Of particular importance is the support that is required when therapeutic modalities which are utilized to enhance protein and DNA synthesis when treating injured patients. Electrotherapeutic devices which accelerate healing require additional nutritional support. Devices like the Electro-Acuscope enhance ATP production but must have the building blocks which are carbohydrates. It is not uncommon for some patients to experience hypoglycemic episodes when receiving therapy in the office. Research suggests addition of specific micronutrients affect a more favorable outcome in injury or illness recovery. The most common nutrients that are used to support healing are glutamine (GLN), arginine (ARG), omega-3 fatty acids, nucleotides (RNA), and trace elements. Immuno-nutrition to enhance the immune function can also influence outcome. This includes branched chain amino acids, selenium, zinc, vitamin C, B1,2,3,5,6,12, Aloe Vera, garlic, etc. Glutamine may be the most essential micronutrient in trauma or illness. It is the fuel for enterocytes, lymphocytes, and macrophage cells. Glutamine deficiency compromises the barrier function of the intestinal epithelium and impaired immune system function. Arginine is essential under conditions of high stress or infection. High doses of Arginine enhance secretion of growth hormone, insulin-like growth factor, pituitary growth hormone, prolactin, etc. Arginine is the precursor of synthesis of nitrate, nitrite, and nitric oxide which is important to macrophage function. Omega-3 fatty acids (fish oils) reduce inflammation and stimulate the immune system. There is a caution on excessive intake of arginine. Many people have a deficiency of a necessary enzyme to metabolize arginine, arginine succinase. If the arginine intake exceeds the body's capacity to metabolize it, there is a buildup of arginine succinic acid and is antagonistic to tryptophan which is necessary for the health of the cerebellum. Equilibrium (balance) function is performed by the cerebellum in the brain and therefore excess arginine can lead to loss of balance (disequilibrium) as demonstrated by an ataxic gait. If this occurs high doses of tryptophan are administered to reduce the interference. Purine and pyramidine nucleotides (adenine, guanine, thymidine, and uracil) are precursors for DNA and RNA synthesis and are essential for cellular energetic production or ATP. They also
play a role in physiological mediators (c-amp). These agents improve killer cell activity which enhance resistance to infection. Vitamin and mineral requirements are also increased to accommodate the increased energy requirements, increased rate of protein synthesis, increased needs of the immune system, increased rate of cell proliferation, etc. If drugs are used they must be detoxified which requires more vitamin and mineral support. If there is a resulting vitamin antioxidant deficiency, this can lead to poor vascular integrity and decreased cardiac strength. There can also be electrolyte and fluid imbalance which alters the blood pressure. Micronutrients are increased when energy or protein intake is increased or when there is tissue injury, skeletal disease or injury. There needs to be adjustment to micronutrients when there is fluid or electrolyte imbalance. Blood loss requires increased micronutrients as well as if the immune system is activated. Damage to organ systems demand specific nutritional support: Gastrointestinal disease or injury alters release of nutrients from dietary sources by interfering with digestion and absorption. It further alters appetite and satiation which effect food intake. There is also diminished immunological protection. Liver damage or disease reduces nutrient storage and nutrient transport proteins. There is impairment of protein metabolism resulting in a buildup of amino nitrogen (ammonia) as well as decreased albumin synthesis. There is a loss glucose balance resulting in hypoglycemia and glucose intolerance. Vitamin D activation/deactivation is altered and there is alteration in fluid balance in the body. There is abnormal vitamin and mineral metabolism and decreased nutritional availability. Kidney disease or injury decreases excretion of nutrient metabolites, causes insulin resistance, causes fluid and electrolyte imbalance and abnormal calcium/phosphorus metabolism from altered vitamin D activation. Cardiovascular disease or injury reduces cardiac output which alters the zeta potential and leads to blood sludge. There is impaired delivery of oxygen and nutrients to the tissue. There is altered fluid and electrolyte balance. There is altered metabolic rate as well as inability to maintain body temperature. There can be a buildup of CO2 and alteration of acid base balance. Lung disease or injury increases energy expenditure for respiration, alters acid-base balance, and alters oxygen and carbon dioxide exchange in the body. If there is renal disease or hepatic encephalopathy, protein intake needs to be restricted. Proteins are to be increased when there is acute or chronic renal disease with dialysis.
Caloric intake is increased with increased metabolic stress or acute renal disease without dialysis. Calories are decreased in acute or chronic renal disease with dialysis. Fluid intake should be increased when there is a fever or metabolic stress. Fluid and sodium should be decreased when there is renal disease or liver disease. Quality of nutrition (nourishment) is important: Nutrients need to be in a bio-available form. Ions or molecules need to be able to be transported into the cells transport channels. Very subtle and often neglected factors by many nutritional product manufacturers can make the difference in healthful nourishment and merely nutritional components that are poorly utilized or have to be converted by the body to provide life support. Nutritional Support Should Be Monitored: A positive nitrogen balance must be achieved by supplying an adequate amount of protein. This can vary according to the healing phase of the injury. In general, elderly patients cannot tolerate high protein loads without digestive support. Head injury patients have a 40% increase in nitrogen balance due to stress hormone flow. Energy expenditure can also be increased by hyperventilation, fever, or seizures. Sedatives (including alcohol) decrease energy expenditure by as much as 40%. If there is paralysis or disability, that can reduce caloric demand as well. Excessive calories (overfeeding) causes impaired glucose control, suppression of chemo tactic/phagocytic actions (damaged cellular cleanup) of monocytes due to hyperglycemia and respiratory dysfunction from excess CO2 production. It is important to monitor the nutritional support as well as the healing with appropriate testing. Nitrogen balance is paramount to monitor the nutritional prescription of the trauma patient. Serum pre-albumin levels correlate well with nitrogen balance in trauma patients. Acute phase reactants such as C-reactive protein, fibrinogen, alpha-1-glycoprotein should also be monitored. It makes no difference whether an improved nutritional state or improved healing leads to improvement in test values. Optimal nitrogen balance is still the goal of the nutritional prescription and is the single most predictor of a favorable outcome in healing. That is because nitrogen balance measures the net effect of protein synthesis (healing) and degradation (atrophy of tissue). There are many methods that monitor nutritional support and/or healing: Body measurement (weight change, girth measurements, etc.) Body composition (body fat, lean body mass, total body water, etc.) Metabolic testing (urine, blood, feces) Immunological testing (delayed hypersensitivity testing, antibody production, immune cell testing) Blood serum chemistry assay (pre-albumin, etc.)
Regardless of the composition of macronutrient or micronutrient support, the composition must be iso-nitrogenous and iso-caloric, i.e. not too much and not too little. This usually requires testing to properly determine. Select testing to monitor immune cell nutrition as well as amino acid and fatty acid levels may be done. This is particularly important in chronically ill patients. These factors form the fundamental support needed by patients that are ill or injured regardless of severity. Even repetitive micro trauma puts a stress on the body's reserves that over time if not properly supported can have a poor outcome. Nutrition is the fundamental medicine.