"Nutritional Assessment" TUMOR TIDBITS, A BIWEEKLY EMAIL NEWSLETTER FROM GULF COAST VETERINARY ONCOLOGY Number 73; October 11, 2002. ======================================================================= THIS WEEK'S TUMOR TIDBIT: NUTRITIONAL ASSESSMENT ======================================================================= PATIENT ASSESSMENT AND NUTRITIONAL NEEDS The veterinary community is beginning to appreciate the relationship between enteral nutritional support and proper medical and surgical management of companion animals. The optimal route for meeting the nutritional requirements of companion animals is the gastrointestinal tract. Enteral nutritional support uses some part of the gastrointestinal tract to feed the patient that cannot or will not eat but can digest and absorb nutrients. Enteral feeding is the simplest, fastest, safest, and least expensive method of feeding companion animals that require nutritional support. Assessment of the patient requiring enteral nutritional support should include an assessment of the animal, the current diet, and feeding management. The combined subjective and objective data collected can be used to formulate an appropriate enteral feeding plan and define the specific nutritional goals to manage the patient. The feeding plan then must be implemented and monitored and if the animal goes home with an enteral tube the client must be educated. Frequently the veterinarian must rely on clinical judgment, rather than on objective data, to decide to institute enteral nutritional support. However, simple tools such as thorough clinical assessment are surprisingly sensitive. The primary goal of nutritional assessment is to predict the animal that can benefit from nutritional support. In the future, other techniques may be available clinically to provide a more objective and quantitative assessment of nutritional status. Anorexia and malnutrition, particularly protein calorie deficiency, is common in companion animals requiring nutritional support. Malnutrition reduces synthesis of plasma proteins, impairs wound healing, and decreases immune response. It is essential for the veterinarian to assess the nutritional status of the patient on initial presentation and to reassess the animal at appropriate intervals after nutritional intervention to determine whether a change in nutritional status has occurred. PATIENT ASSESSMENT Nutritional assessment of the companion animal is a structured process that includes review of the signalment, history and medical record; physical examination; laboratory evaluation; and, estimation of nutritional requirements based on physiological state. Review of the signalment, history and medical record should include questions related to changes in body weight, food intake, and drugs and other therapies that may affect appetite and/or nutrient metabolism. The medical record may provide important objective information that may provide clues to the animal's nutritional status. There are several drug/nutrient interactions that may influence dietary intake or nutritional requirements. For example, animals receiving diuretics may have increased needs for potassium, magnesium, and calcium. The patient's physiological state should be defined by collecting information related to body weight, body condition scoring, growth rate, reproductive status, species, and the nature and duration of the presenting illness. These parameters affect the nutrient requirements of the animal for a given nutrient. Furthermore, the client should be questioned about environmental factors, such as activity and housing, which could also alter nutrient requirements. The client should also be questioned about the animal's dietary history including the current diet, eating habits, and feeding management. The dietary history should strive to identify all items of food being consumed by the animal including table scraps, treats, and supplements. The amount of each food offered and consumed should be specified and factors that could affect intake, such as other animals in the household, should be recorded. Companion animals that have been anorectic or had restricted food intake for longer than 3 days may benefit from nutritional intervention. CLINICAL EVALUATION Physical examination can help to define the nutritional status of companion animals. Body weight and body condition scoring (score of 1 to 5, with 1 being thin and 5 being obese) provides a subjective estimation of the animals body composition. Fat cover over the ribs, down the topline, around the tailhead, and ventrally along the abdomen should be evaluated. Body condition scoring can be combined with zoometric measurements such as pelvic circumference to provide a better estimate of body fat. Body weight can be compared to usual or optimum body weight and to breed standards. Nutritional support is indicated if the patient has recently lost more than 10% of usual or optimum body weight. The patient's general appearance should be assessed including the presence or absence of edema, ascites, and nonhealing wounds. Evaluation of hair coat, skin, and nails may provide an indication of malnutrition. Growth retardation, muscle weakness, or atrophy aids in the identification of catabolic, critically ill patients. Organ dysfunction, such as the liver, heart, kidneys, or lungs may serve to explain poor body weight and condition and will help to define the most appropriate nutrient profile for the enteral diet. Laboratory evaluation may serve as objective indicators of nutritional status, however no single laboratory parameter analyzed routinely in veterinary medicine can accurately assess nutritional status. Laboratory tests such as albumin, lymphocyte count, pack cell volume and total protein may provide insight into the patient's nutritional status. For example, hypoalbuminemia may indicate visceral protein depletion due to chronic undernutrition or protein loss. In humans, hypoalbuminemia correlates with increased morbidity and mortality rates and longer hospital stays. In the future, shorter half-life serum proteins such as prealbumin, transferrin, retinol- binding protein, or fibronectin may be available to assess short-term changes in nutritional status. Serum glucose is important to assess in severely stressed, catabolic patients. Furthermore, since malnutrition affects the immune status of the patient perhaps, in the future, an immune profile could be developed to provide a more sensitive assessment of nutritional status. Serum biochemical profile changes associated with major organ dysfunction may provide indications of problems that may be nutrient sensitive and therefore affect the selection of the enteral diet. For example, if the patient requiring enteral nutritional support has associated renal or liver disease, diet selection would dictate a modification in the levels of certain nutrients. Other laboratory tests that may be of value in nutritional assessment include urinalysis and fecal analysis. SELECTING THE RIGHT DIET In next week's Tumor Tidbit, information about selecting the right diet and how to develop the proper enteral feeding plan will be discussed. ======================================================================= We hope this info helps and don't hesitate to call us Gulf Coast Veterinary Oncology! Kevin A. Hahn, DVM, Phd, Diplomate ACVIM (Oncology), drhahn@gcvs.com Janet K. Carreras, VMD, Residency Completed and Certification Examination Passed, ACVIM (Oncology), drcarreras@gcvs.com Glen K. King, DVM, MS, Diplomate ACVR (Radiology & Radiation Therapy), drking@gcvs.com Gulf Coast Veterinary Diagnostic Imaging & Oncology 1111 West Loop South, Suite 150, Houston, TX 77027 P: 713.693.1166 F: 713.693.1167 W: www.gcvs.com