Nutrition in Clinical Practice

Sarcopenia is a relatively new concept in the medical literature, initially intended to describe the loss of lean body mass that occurs with aging. More recently, sarcopenia has been described in various forms of chronic disease, including patients with end-stage organ disease awaiting transplantation. The presence of sarcopenia is an important marker in transplant patients, since it has been linked to poorer pre- and posttransplant outcomes compared with patients with preserved muscle mass. The mechanisms and natural history of sarcopenia in transplant patients are incompletely understood, and there are currently no therapies proven to mitigate or reverse the process. This article reviews the current understanding of the prevalence and clinical significance of sarcopenia in transplant patients and highlights important areas of future research.

The increasing rate of societal obesity is also affecting the transplant world through obesity in candidates and donors as well as its posttransplant repercussions. Being overweight and obese has been shown to have significant effects on both short- and long-term complications as well as patient and graft survival. However, much of the comorbidity can be controlled or prevented with careful patient selection and aggressive management. A team approach to managing obesity and its comorbidities both pre- and posttransplant is essential for successful transplant outcomes. Complicating understanding the results of obesity research is the inclusion different weight categories, use of listing vs transplant weights, patient populations large enough for statistical power, and changes in transplant management, especially immunosuppression protocols, anti-infection protocols, and operative techniques. Much more research is needed regarding many elements, including safe weight loss before transplantation, prevention of weight gain after transplant, genomic influences, and the role of bariatric surgery in the transplant process.

Survival rates for pediatric transplant recipients and organ grafts have increased due to improvements in surgical techniques and with immunosuppressant treatment therapies. Interdisciplinary management after pediatric organ transplantation is essential to assist not only with the complex medical issues and complications that can result from immunosuppressant therapy but also with the achievement of normal growth and development. Impaired growth is a complication frequently experienced by pediatric transplant patients. The presence or absence of impaired growth is affected by the length of illness prior to transplant, graft function, the use of corticosteroids, and the development of infectious complications after surgery. A review of posttransplant nutrition assessment, nutrition requirements, and nutrition goals is provided. In addition, a case series of experiences with nutrition management of pediatric solid organ transplant recipients is described.

Extracorporeal membrane oxygenation (ECMO) is used to treat patients with severe acute respiratory distress syndrome or severe cardiac and/or respiratory failure that is unresponsive to conventional ventilator therapy. Provision of adequate nutrition support can be challenging due to hemodynamic alterations encountered in these critically ill patients. Although ECMO is an established therapy for many aspects of organ transplant in the pre- and posttransplant phases, there is a paucity of published data for this patient population. Clinical guidelines are available for the nutrition support of neonates supported with ECMO, but no guidelines have been established for the adult population receiving ECMO support. Review of published reports and personal experience indicates that early enteral nutrition support can be well tolerated by transplant patients receiving either venovenous or venoarterial ECMO, if care is taken to adequately assess potential barriers to optimal nutrition support. Until specific guidelines are developed for patients receiving ECMO, it appears that the guidelines for the provision and assessment of nutrition support therapy in the adult critically ill patient provide the best guidance for the nutrition support clinician who is caring for the patient receiving ECMO support.

Kidney transplantation is the preferred option for patients with end-stage renal disease facing the need for dialysis because it provides maximum survival benefit. The number of people seeking kidney transplantation greatly exceeds available deceased donor organs. Organs from live donors provide a survival advantage over organs from deceased donors while also broadening the pool of available organs. The purpose of this review is to discuss the clinical guidelines that pertain to live kidney organ donation and to describe the nutrition evaluation and care of live kidney donors. The process for living kidney donation is dictated by policies centered on protecting the donor. In a perfect world, the living donor would present with a flawless medical examination and a benign family health history. The obesity epidemic has emerged as a major health concern. Live donor programs are faced with evaluating increasing numbers of obese candidates. These “medically complex donors” may present with obesity and its associated comorbid conditions, including hypertension, impaired glycemic control, and kidney stone disease. The dietitian’s role in the live donor program is not well defined. Participation in the living donor selection meeting, where details of the evaluation are summarized, provides a platform for risk stratification and identification of donors who are at increased lifetime risk for poor personal health outcomes. Guiding the donor toward maintenance of a healthy weight through diet and lifestyle choices is a legitimate goal to minimize future health risks.

A biomarker can be defined as a measurable variable that may be used as an indicator of a given biological state or condition. Biomarkers have been used in health and disease for diagnostic purposes, as tools to assess effectiveness of nutritional or drug intervention, or as risk markers to predict the development of certain diseases. In nutrition studies, selecting appropriate biomarkers is important to assess compliance, or incidence of a particular dietary component in the biochemistry of the organism, and in the diagnosis and prognosis of nutrition-related diseases. Metabolic syndrome is a cluster of cardiovascular risk factors that occur simultaneously in the same individual, and it is associated with systemic alterations that may involve several organs and tissues. Given its close association with obesity and the increasing prevalence of obesity worldwide, identifying obese individuals at risk for metabolic syndrome is a major clinical priority. Biomarkers for metabolic syndrome are therefore potential important tools to maximize the effectiveness of treatment in subjects who would likely benefit the most. Choice of biomarkers may be challenging due to the complexity of the syndrome, and this article will mainly focus on nutrition biomarkers related to the diagnosis and prognosis of the metabolic syndrome.

We published one of the first prospective randomized controlled trials evaluating early postoperative tube feeding (TF) in liver transplant recipients nearly 20 years ago. That first study showed that early posttransplant TF was safe and well tolerated; the study results also suggested that early TF could reduce posttransplant infection rates. This Pivotal Paper review evaluates the past, present, and future of early postoperative TF in liver transplantation. This article identifies what nutrition support findings more than 2 decades ago were the basis for attempting postoperative TF in liver transplantation. The results of our study, its unique findings, and shortcomings are summarized. Other subsequent studies of post–liver transplant TF are evaluated with a focus on effects on posttransplant infection rates. Finally, current transplant challenges, including donor organ shortage, increased severity of patients’ pretransplant condition, expansion of living donor options, changes in immunosuppression, and use of specialized nutrients, are discussed in the context of how and why these factors affect nutrition support.

Standard predictive equations may under- or overestimate caloric requirements in disease states such as obesity or in patients with a low body mass index (BMI). Although this principle is common knowledge among nutrition specialists, it is often not prioritized with other clinicians outside the intensive care unit (ICU). Indirect calorimetry (IC) is often used in the ICU to estimate caloric requirements. This article outlines a very complicated case of a cachectic man with an enterocutaneous fistula who had lost more than 50% of body weight over 2 years. In rehabilitating this patient, we found that the most common formulas of basal needs greatly underestimated the calories required to prepare him for restorative surgery. Key learning points are that in malnourished ambulatory patients, predictive equations may not adequately estimate caloric needs and IC may be required.

Background: In 2009, an intestinal rehabilitation team implemented feeding guidelines for infants following gastrointestinal surgery at our institution. The purpose of this study was to determine the effect of enteral feeding guidelines on the incidence of parenteral nutrition (PN)–associated liver disease (PNALD) in infants with surgically managed necrotizing enterocolitis (NEC). Methods: This retrospective study included infants treated during 18-month time periods before and after the implementation of feeding guidelines. PNALD diagnosis was based on serum direct bilirubin >2 mg/dL after ≥14 days of PN exposure. Results: Of the 140 infants identified, 64 were surgically managed and included in the analysis. The duration of PN and the time nil per os (NPO) were significantly reduced after guideline implementation from a median of 106 days to 65 days (P = .03) and from 29 days to 16 days (P = .02), respectively. The incidence of PNALD decreased from 73% before guideline implementation to 42% after guideline implementation (P = .01). Conclusions: Implementation of feeding guidelines resulted in decreased time NPO and duration of PN support. Significantly fewer infants developed PNALD after guideline implementation. These data suggest that feeding guidelines may expedite the transition from PN to enteral nutrition and may improve outcomes.

Background: Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow limitation and is associated with weight loss and decreased muscle strength and exercise capacity. Methods: A double-blinded randomized controlled trial of 32 male COPD patients (age, 54.94 ± 11.27 years) was carried out to assess effects of anabolic steroid in terms of a daily high-protein, high-calorie diet alone or one combined with anabolic steroids on body composition, lung function, and health-related quality of life (HRQL). Outcomes were assessed by anthropometric and spirometric measurements, peak expiratory flow rate, partial pressure of oxygen in arterial blood, 6-minute walk test (6MWT), hand grip test, and HRQL index scores. Measurements were made at baseline and end of treatment (6 weeks). Results: All patients showed significant difference (P < .001) in pulmonary function parameters and anthropometric measurements after 6 weeks of intervention (within-group changes); however, no significant improvement occurred in the pulmonary function parameters between the groups. The difference in exercise capacity (6MWT) and HRQL scores in the treatment group were statistically significant (P < .001) compared with control group after 6 weeks of intervention. In the treatment group, the average 6MWT distance increased from 213.5 m to 268.5 m at 6-week follow-up, and HRQL scores increased from 101.25 to 118.45. Also, HRQL and 6MWT parameters were positively correlated in response to steroid supplementation at the end of the study. Conclusion: Weekly administration of anabolic steroids during 6 weeks increased exercise capacity and quality of life in patients with COPD.

Background: Hypoxic-ischemic encephalopathy (HIE) is a significant cause of morbidity and mortality in the neonatal population. Total body cooling in term infants who meet the criteria for moderate to severe HIE has been shown to be neuroprotective. A decreased core body temperature is known to affect kinetic properties of many enzyme systems in which magnesium is a cofactor. Maintenance of magnesium during therapeutic hypothermia appears to play an important role in neuroprotection. Currently, there are no studies evaluating the effects that therapeutic hypothermia in neonates has on serum magnesium levels and implications for parenteral nutrition (PN) management. Our hypothesis was that neonatal hypothermia would result in hypomagnesemia and require magnesium therapy. Methods: Laboratory measurement of serum magnesium was obtained in all infants during the cooling process. Results: Serum magnesium was depressed (<1.6 mg/dL) in 80% of the infants cooled despite administration of standard PN and required additional magnesium supplementation. Conclusion: Further studies are needed to determine the target magnesium required for PN in hypothermic therapy.