
Editorial
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The loss of muscle mass is a defining characteristic of malnutrition, and there is ongoing interest in the assessment of lean tissue at the bedside. Globally, bioimpedance techniques have been widely appreciated for their noninvasiveness, safety, ease of use, portability, and relatively low cost compared with other clinically available methods. In this brief update, we review the 3 primary types of commercially available bioimpedance devices (single- and multiple-frequency and spectroscopy) and differentiate the underlying theory and current applications of each. We also address limitations and potential opportunities for using these devices at the bedside for clinical assessment. Mixed reports in the validation literature for all bioimpedance approaches have raised questions about absolute accuracy to estimate whole body composition in clinical populations, particularly those with abnormal fluid status and/or body geometry in whom underlying method assumptions may be violated. Careful selection of equations can improve whole body estimates by single- and multiple-frequency techniques; however, not all devices will allow for this approach. Research is increasing on the use of bioimpedance variables including phase angle and impedance ratio as potential markers of nutrition status and/or clinical outcomes; consensus on reference cut-points for interpreting these markers has yet to be established. Novel developments in the bioimpedance spectroscopy approach are allowing for improved fluid management in individuals receiving dialysis; these developments have implications for the clinical management of other conditions associated with fluid overload and may also provide enhanced whole body estimates of lean tissue through new modeling procedures.
Heightened interest in and utilization of parts of the nutrition-focused physical assessment (NFPA) have increased with recent guidelines in defining malnutrition and the call to awareness among healthcare practitioners to recognize, document, and intervene in malnourished patients. Furthermore, an increased prevalence of nutrient deficiencies has been reported in surgical weight loss patients, those with various acute and chronic diseases, and the elderly requiring physical assessment and examination skills to identify these deficiencies. The registered dietitian nutritionist (RDN) can use the NFPA to note physical findings to use along with the other domains in the nutrition assessment to determine the nutrition-related diagnosis, while other nutrition professionals can use the NFPA findings to determine a differential diagnosis. This article outlines the NFPA and how to determine physical findings related to micronutrient deficiencies, which can have a profound impact on overall nutrition status.
A complete nutrition assessment includes several components: medical record review, anthropometric measurements, diet/nutrition intake, interview, and physical examination. The nutrition-focused physical examination (NFPE) can identify or confirm muscle wasting, subcutaneous fat loss, and edema and clarify information gathered during the medical record review. The physical examination component of the nutrition assessment is more critical in pediatric patients because pediatric patients can become malnourished more quickly than adults and because prolonged malnutrition can negatively affect growth and development. In addition, case studies of micronutrient deficiencies, essential fatty acid deficiency, and protein-calorie malnutrition with skin manifestations have been reported in developed countries. The etiologies of the deficiencies are chronic disease, long-term tube feedings, or long-term parenteral nutrition. An NFPE involves an in-depth examination of the patient from head to toe by a trained nutrition professional. Nutrition professionals recognize the importance and value of an NFPE, yet it is seldom completed, particularly in pediatrics, most likely due to lack of training and lack of pediatric-specific information or training opportunities. Although there are similarities between NFPE in pediatric and adult patients such as the techniques used (inspection, palpation, percussion, and auscultation), there are important differences related to growth and development. This review provides an overview of nutrition assessment with focus on the NFPE and aspects unique to the pediatric patient.
Functional status assessment has been recommended as a part of a complete nutrition assessment for decades, but the specific components of this assessment have eluded a consensus definition. The recent Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition consensus criteria for identification of malnutrition include functional assessment determined by handgrip dynamometry, with the understanding that this technique is not practical for use in some patient populations. Other techniques for functional assessment include physical performance measures such as timed gait and chair stands, as well as activities of daily living tools such as the Katz Index, Lawton Scale, and Karnofsky Scale Index. Manual muscle testing and computed tomography scan assessment of lean tissue are other tools that show promise in correlating functional and nutrition assessments. Functional assessment parameters may be least well correlated with nutrition status in older individuals. Despite a number of scientific studies of a variety of tools for functional assessment, there is to date no definitive tool for use in all individuals in all settings. Nutrition scientists and clinicians must continue to collaborate with colleagues in physical and occupational therapy, geriatrics, and nursing to refine current functional assessment tools to more effectively correlate with nutrition and malnutrition assessment parameters.
Differences in body composition are associated with increased disease risk in various stages of life. Despite numerous available methods in assessing body composition (air displacement plethysmography, dual-energy X-ray absorptiometry, bioelectrical impedance, hydrometry, and magnetic resonance imaging), due to innate technical limitations, the ability for one singular method to track body composition over the life span (ie, infancy to adulthood) is challenging and imperfect. The primary goal of this review is to determine if there are body composition methods that can accurately track body composition from infancy into adulthood. After careful consideration and taking into account the best available scientific evidence, we feel air displacement plethysmography is the best instrument at this time for tracking body composition, starting in infancy and forward into adulthood, partly because it is the only “practical” clinical tool currently available for use during infancy.
Growth failure is a common problem in many children with chronic diseases. This article is an overview of the most common causes of growth failure/growth retardation that affect children with a number of chronic diseases. We also briefly review the nutrition considerations and treatment goals. Growth failure is multifactorial in children with chronic conditions, including patients with cystic fibrosis, chronic kidney disease, chronic liver disease, congenital heart disease, human immunodeficiency virus, inflammatory bowel disease, short bowel syndrome, and muscular dystrophies. Important contributory factors to growth failure include increased energy needs, increased energy loss, malabsorption, decreased energy intake, anorexia, pain, vomiting, intestinal obstruction, and inflammatory cytokines. Various metabolic and pathologic abnormalities that are characteristic of chronic diseases further lead to significant malnutrition and growth failure. In addition to treating disease-specific abnormalities, treatment should address the energy and protein deficits, including vitamin and mineral supplements to correct deficiencies, correct metabolic and endocrinologic abnormalities, and include long-term monitoring of weight and growth. Individualized, age-appropriate nutrition intervention will minimize the malnutrition and growth failure seen in children with chronic diseases.
According to the American Society for Parenteral and Enteral Nutrition and Academy of Nutrition and Dietetics criteria, the diagnosis of malnutrition includes an evaluation of muscle and fat. The role of inflammation not only enhances the catabolism of muscle and fat loss but also interferes with anabolism. Dietitians and other nutrition professionals need to understand techniques to appropriately identify losses of muscle and fat to incorporate them into a malnutrition diagnosis. Proper training is imperative to correctly identify muscle and fat wasting in a consistent and reliable manner. Nutrition clinicians should begin incorporating these practices into patient assessments and care plans. The application of these techniques and assessment tools is challenging and continues to be a work in progress. Various scenarios do not allow for clearly defined methods that would lead to a reliable conclusion for diagnosing malnutrition indicating the need for further research.

