How to interpret and apply the results of indirect calorimetry studies: a case-based tutorial.

Evidence is growing that the individual adjustment of energy targets guided by indirect calorimetry (IC) can improve outcome. With the development of a new generation of devices that are easier to use and rapid, it appears important to share knowledge and expertise that may be used to individualize nutrition care. Despite the focus of this tutorial being on one contemporary device, the principles of IC apply across existing devices and can assist tailoring the nutrition prescription and in assessing response to nutrition therapy. The present tutorial addresses its clinical application in intubated mechanically ventilated and spontaneously breathing adult patients (canopy), i.e. it covers the range from critical illness to outpatients. The cases that are presented show how the measured energy expenditure (mEE), and the respiratory quotient (RQ), i.e. the ratio of expired CO2 to consumed O2, should be applied in different cases, to adapt and individualize nutrition prescription, as it is a good marker of over- or underfeeding at the different stages of disease. The RQ also informs about the patient's body's capacity to use different substrates: the variations of RQ indicating the metabolic changes revealing insufficient or excessive feeding. The different cases reflect the use of a new generation device as a metabolic monitor that should be combined with other clinical observations and laboratory biomarkers. The tutorial also points to some shortcomings of the method, proposing alternatives.

Parenteral nutrition in the hospital setting/short-term parenteral nutrition.

PURPOSE: This article is based on presentations and discussions held at the International Safety and Quality of Parenteral Nutrition (PN) Summit concerning the acute care setting. Some European practices presented in this article do not conform with USP general chapter <797> requirements. Nevertheless, the purpose is to cover the challenges experienced in delivering high-quality PN within hospitals in the United States and Europe, in order to share best practices and experiences more widely. SUMMARY: Core issues regarding the PN process within an acute care setting are largely the same everywhere: There are ongoing pressures for greater efficiency, optimization, and also concurrent commitments to make PN safer for patients. Within Europe, in recent years, the use of market-authorized multi-chamber bags (MCBs) has increased greatly, mainly for safety, cost-effectiveness, and efficiency purposes. However, in the US, hospitals with low PN volumes may face particular challenges, as automated compounding equipment is often unaffordable in this setting and the variety of available MCBs is limited. This can result in the need to operate several PN systems in parallel, adding to the complexity of the PN use process. Ongoing PN quality and safety initiatives from US institutions with various PN volumes are presented. In the future, the availability of a greater selection of MCBs in the US may increase, leading to a reduction in dependence on compounded PN, as has been seen in many European countries. CONCLUSION: The examples presented may encourage improvements in the safety and quality of PN within the acute care setting worldwide.

Parenteral nutrition in clinical practice: International challenges and strategies.

PURPOSE: Parenteral nutrition (PN) is an established therapy when oral/enteral feeding is not sufficient or is contraindicated, but nevertheless PN remains a complex, high-alert medication that is susceptible to errors that may affect patient safety. Over time, considerable progress has been made to make PN practices safer. The purpose of this article is to address ongoing challenges to improve the PN use process from prescription to administration and monitoring, and to outline practical aspects fostering the safety, quality, and cost-effectiveness of PN, as discussed at the International Safety and Quality of PN Summit. SUMMARY: Opportunities to improve the PN use process in clinical practice include the promotion of inter-disciplinary communication, vigilant surveillance for complications, staff education to increase competency, and more consistent use of advanced technologies that allow automated safety checks throughout the PN process. Topics covered include considerations on PN formulations, including the value of intravenous lipid emulsions (ILEs), trends in compounding PN, the current and future role of market-authorized multi-chamber PN bags containing all 3 macronutrients (amino acids, glucose/dextrose, and ILE) in the United States and in Europe, and strategies to cope with the increasing global problem of PN product shortages. CONCLUSION: This review outlines potential strategies to use in clinical practice to overcome ongoing challenges throughout the PN use process, and ultimately promote PN patient safety.

Safety and quality of parenteral nutrition: Areas for improvement and future perspectives.

PURPOSE: This article is based on presentations and discussions held at the International Safety and Quality of Parenteral Nutrition (PN) Summit (held November 8-10, 2021, at Charleston, SC, and Bad Homburg, Germany) and aims to raise awareness concerning unresolved issues associated with the PN process and potential future directions, including a greater emphasis on patients' perspectives and the role of patient support. SUMMARY: Ensuring that every patient in need receives adequate PN support remains challenging. It is important to have a standardized approach to identify nutritional risk and requirements using validated nutritional screening and assessment tools. Gaps between optimal and actual clinical practices need to be identified and closed, and responsibilities in the nutrition support team clarified. Use of modern technology opens up opportunities to decrease workloads or liberate resources, allowing a more personalized care approach. Patient-centered care has gained in importance and is an emerging topic within clinical nutrition, in part because patients often have different priorities and concerns than healthcare professionals. Regular assessment of health-related quality of life, functional outcomes, and/or overall patient well-being should all be performed for PN patients. This will generate patient-centric data, which should be integrated into care plans. Finally, communication and patient education are prerequisites for patients' commitment to health and for fostering adherence to PN regimes. CONCLUSION: Moving closer to optimal nutritional care requires input from healthcare professionals and patients. Patient-centered care and greater emphasis on patient perspectives and priorities within clinical nutrition are essential to help further improve clinical nutrition.

LLL 44 - Module 3: Micronutrients in Chronic disease.

Micronutrients (MN), i.e. trace elements and vitamins, are essential organic molecules, which are required in the diet in relatively small amounts in any form of nutrition (oral, enteral, parenteral). The probability of MN depletion or deficiencies should be considered in all chronic illnesses, especially in those that can interfere with intake, digestion, or intestinal absorption. Low socio-economic status and food deprivation are recognized as the most prevalent reasons for MN deficiencies world-wide. Elderly multimorbid patients with multimodal therapy, as well as patients with long-lasting menu restrictions, are at high risk for both disease related malnutrition as well as multiple MN deficiencies, needing careful specific follow-up. The importance of monitoring MN blood levels along with CRP is essential for optimal care. Drug interactions are also highlighted. In patients with chronic conditions depending on medical nutrition therapy, the provision of adequate dietary reference intakes (DRI) of MN doses and monitoring of their adequacy belongs to standard of care.

Expert consensus statements and summary of proceedings from the International Safety and Quality of Parenteral Nutrition Summit.

PURPOSE: The International Safety and Quality of Parenteral Nutrition (PN) Summit consisted of presentations, discussions, and formulation of consensus statements. The purpose here is to briefly summarize the summit and to present the consensus statements. SUMMARY: There was a high degree of consensus, with all statements approved by all authors/summit experts. These consensus statements should be regarded not as formal guidelines but rather as best-practice guidance intended to complement national and international nutrition society evidence-based guidelines and position statements. This article also summarizes key discussion topics from the summit, encompassing up-to-date knowledge and practical guidance concerning PN safety and quality in various countries and clinical settings, focusing on adult patients. Clear geographical differences exist between practices in Europe and the United States, and different approaches to improve the safety, quality, and cost-effectiveness of PN vary, particularly with regard to the delivery systems used. Discussion between experts allowed for an exchange of practical experience in optimizing PN use processes, opportunities for standardization, use of electronic systems, potential improvements in PN formulations, better management during PN component shortages, and practical guidance to address patients' needs, particularly during long-term/home PN. CONCLUSION: The consensus statements are the collective opinion of the panel members and form best-practice guidance. The authors intend that this guidance may help to improve the safety and quality of PN in a variety of settings by bridging the gap between published guideline recommendations and common practical issues.

LLL 44-1 Micronutrients in clinical nutrition: Trace elements.

BACKGROUND: Trace elements are an essential component of metabolism and medical nutrition therapy, with key roles in metabolic pathways, antioxidation, and immunity, which the present course aims at summarizing. RESULTS: Medical nutrition therapy includes the provision of all essential trace elements. The clinical essential issues are summarized for Copper, Iron, Selenium, Zinc, Iodine, Chromium, Molybdenum, and Manganese: the optimal analytical techniques are presented. The delivery of all these elements occurs nearly automatically when the patient is fed with enteral nutrition, but always requires separate prescription in case of parenteral nutrition. Isolated deficiencies may occur, and some patients have increased requirements, therefore a regular monitoring is required. The clinicians should always consider the impact of inflammation on blood levels, mostly lowering them even in absence of deficiency. CONCLUSION: This text summarises the most relevant clinical manifestations of trace element depletion and deficiency, the difficulties in assessing status, and makes practical recommendations for provision for enteral and parenteral nutrition.

LLL 44 - 2 - Micronutrients in clinical nutrition: Vitamins.

Vitamins are essential organic molecules, which are required in the diet in relatively small amounts in any form of nutrition (oral, enteral, parenteral). Despite the small amounts that are required, the vitamins are essential both for maintenance of health, growth, and treatment of disease. After reminding about the principal function of all the vitamins, their needs and the clinical consequences of their deficit, the text present some common clinical problems: the impact of inflammation on the assessment of status. The reasons and diseases which cause increased requirements are presented, with the indications to monitoring of blood levels which remain the classical way to assess status in clinical settings. The text summarises the most relevant clinical manifestations of vitamins depletion and deficiency, the difficulties in assessing status, and makes recommendations for provision for medical nutrition therapy.

LLL 44-4 : Micronutrients in acute disease and critical illness.

Micronutrients (MN), i.e. trace elements and vitamins, are essential components of the diet in relatively small amounts in any form of nutrition, with special needs in critically ill patients. Critical illness is characterised by the presence of inflammation and oxidative stress. MNs are tightly involved in antioxidant and immune defences. In addition, some conditions, and treatments result in large losses of biological fluids containing MNs: therefore, acute renal injury requiring renal replacement therapy, acute intestinal failure, and major burns and trauma are at high risk of acute depletion of body stores, and of deficiency. MN requirements are increased above standard DRI. Blood level interpretation is complicated by inflammation: some biomarkers assist the status determination. Due to the acute challenges of critical illness, it of utmost importance to cover the needs to maintain the organism's endogenous immune and antioxidant defences, and capacity to repair tissues. Practical strategies are proposed.

Micronutrient deficiency and supplements in schoolchildren and teenagers.

PURPOSE OF REVIEW: The essential micronutrients are corner stones in the functional and physical development. Early deficiency has life-long consequences. While awareness about iron deficiency is relatively high, it remains lower for other micronutrients. This review aims at reporting on recent data and attracting attention to the high prevalence of micronutrient deficiencies in school-age and adolescent individuals. RECENT FINDINGS: Iron deficiency anaemia remains highly prevalent worldwide and the most frequent deficiency but can be corrected with simple tools ranging from food fortification, nutritional intervention, and to supplements. The link between micronutrient (MN) deficiency and neurobehavioral disorders is increasingly established and is worrying even in Western countries. Paediatric individuals are prone to imbalanced diets and picky eating behaviour, and their diets may then become incomplete: the highest risk for deficiency is observed for iron, zinc and vitamin D. SUMMARY: There is not much new information, but rather confirmation of the importance of health policies. Well conducted randomized controlled trials confirm that deficiencies can be corrected efficiently including with food fortification, and result in clinical benefits. Individual complementation should be considered in children and adolescents with proven deficiency.

ESPEN practical short micronutrient guideline.

BACKGROUND: Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. The importance of MNs in common pathologies is recognized by recent research, with deficiencies significantly impacting the outcome. OBJECTIVE: This short version of the guideline aims to provide practical recommendations for clinical practice. METHODS: An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL for the initial guideline. The search focused on physiological data, historical evidence (for papers published before PubMed release in 1996), and observational and/or randomized trials. For each MN, the main functions, optimal analytical methods, impact of inflammation, potential toxicity, and provision during enteral or parenteral nutrition were addressed. The SOP wording was applied for strength of recommendations. RESULTS: The limited number of interventional trials prevented meta-analysis and led to a low level of evidence for most recommendations. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90 % of votes. Altogether the guideline proposes 3 general recommendations and specific recommendations for the 26 MNs. Monitoring and management strategies are proposed. CONCLUSION: This short version of the MN guideline should facilitate handling of the MNs in at-risk diseases, whilst offering practical advice on MN provision and monitoring during nutritional support.

Combining proteins with n-3 PUFAs (EPA + DHA) and their inflammation pro-resolution mediators for preservation of skeletal muscle mass.

The optimal feeding strategy for critically ill patients is still debated, but feeding must be adapted to individual patient needs. Critically ill patients are at risk of muscle catabolism, leading to loss of muscle mass and its consequent clinical impacts. Timing of introduction of feeding and protein targets have been explored in recent trials. These suggest that "moderate" protein provision (maximum 1.2 g/kg/day) is best during the initial stages of illness. Unresolved inflammation may be a key factor in driving muscle catabolism. The omega-3 (n-3) fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are substrates for synthesis of mediators termed specialized pro-resolving mediators or SPMs that actively resolve inflammation. There is evidence from other settings that high-dose oral EPA + DHA increases muscle protein synthesis, decreases muscle protein breakdown, and maintains muscle mass. SPMs may be responsible for some of these effects, especially upon muscle protein breakdown. Given these findings, provision of EPA and DHA as part of medical nutritional therapy in critically ill patients at risk of loss of muscle mass seems to be a strategy to prevent the persistence of inflammation and the related anabolic resistance and muscle loss.

The science of micronutrients in clinical practice - Report on the ESPEN symposium.

BACKGROUND & AIMS: The European Society for Clinical Nutrition and Metabolism published its first clinical guidelines for use of micronutrients (MNs) in 2022. A two-day web symposium was organized in November 2022 discussing how to apply the guidelines in clinical practice. The present paper reports the main findings of this symposium. METHODS: Current evidence was discussed, the first day being devoted to clarifying the biology underlying the guidelines, especially regarding the definition of deficiency, the impact of inflammation, and the roles in antioxidant defences and immunity. The second day focused on clinical situations with high prevalence of MN depletion and deficiency. RESULTS: The importance of the determination of MN status in patients at risk and diagnosis of deficiencies is still insufficiently perceived, considering the essential role of MNs in immune and antioxidant defences. Epidemiological data show that deficiencies of several MNs (iron, iodine, vitamin D) are a global problem that affects human health and well-being including immune responses such as to vaccination. Clinical conditions frequently associated with MN deficiencies were discussed including cancer, obesity with impact of bariatric surgery, diseases of the gastrointestinal tract, critical illness, and aging. In all these conditions, MN deficiency is associated with worsening of outcomes. The recurrent problem of shortage of MN products, but also lack of individual MN-products is a worldwide problem. CONCLUSION: Despite important progress in epidemiology and clinical nutrition, numerous gaps in practice persist. MN depletion and deficiency are frequently insufficiently searched for in clinical conditions, leading to inadequate treatment. The symposium concluded that more research and continued education are required to improve patient outcome.

Personalized nutrition therapy in critical care: 10 expert recommendations.

Personalization of ICU nutrition is essential to future of critical care. Recommendations from American/European guidelines and practice suggestions incorporating recent literature are presented. Low-dose enteral nutrition (EN) or parenteral nutrition (PN) can be started within 48 h of admission. While EN is preferred route of delivery, new data highlight PN can be given safely without increased risk; thus, when early EN is not feasible, provision of isocaloric PN is effective and results in similar outcomes. Indirect calorimetry (IC) measurement of energy expenditure (EE) is recommended by both European/American guidelines after stabilization post-ICU admission. Below-measured EE (~ 70%) targets should be used during early phase and increased to match EE later in stay. Low-dose protein delivery can be used early (~ D1-2) (< 0.8 g/kg/d) and progressed to ≥ 1.2 g/kg/d as patients stabilize, with consideration of avoiding higher protein in unstable patients and in acute kidney injury not on CRRT. Intermittent-feeding schedules hold promise for further research. Clinicians must be aware of delivered energy/protein and what percentage of targets delivered nutrition represents. Computerized nutrition monitoring systems/platforms have become widely available. In patients at risk of micronutrient/vitamin losses (i.e., CRRT), evaluation of micronutrient levels should be considered post-ICU days 5-7 with repletion of deficiencies where indicated. In future, we hope use of muscle monitors such as ultrasound, CT scan, and/or BIA will be utilized to assess nutrition risk and monitor response to nutrition. Use of specialized anabolic nutrients such as HMB, creatine, and leucine to improve strength/muscle mass is promising in other populations and deserves future study. In post-ICU setting, continued use of IC measurement and other muscle measures should be considered to guide nutrition. Research on using rehabilitation interventions such as cardiopulmonary exercise testing (CPET) to guide post-ICU exercise/rehabilitation prescription and using anabolic agents such as testosterone/oxandrolone to promote post-ICU recovery is needed.

ESPEN practical and partially revised guideline: Clinical nutrition in the intensive care unit.

Following the new ESPEN Standard Operating Procedures, the previous 2019 guideline to provide best medical nutritional therapy to critically ill patients has been shortened and partially revised. Following this update, we propose this publication as a practical guideline based on the published scientific guideline, but shortened and illustrated by flow charts. The main goal of this practical guideline is to increase understanding and allow the practitioner to implement the Nutrition in the ICU guidelines. All the items discussed in the previous guidelines are included as well as special conditions.

An update on essential micronutrients in critical illness.

PURPOSE OF REVIEW: Numerous micronutrients are involved in antioxidant and immune defence, while their blood concentrations are frequently low in critically ill patients: this has fuelled many supplementation trials. Numerous observational, randomized studies have been published, which are presented herein. RECENT FINDINGS: Micronutrient concentrations must be analysed considering the context of the inflammatory response in critical illness. Low levels do not always indicate a deficiency without objective micronutrients losses with biological fluids. Nevertheless, higher needs and deficiencies are frequent for some micronutrients, such as thiamine, vitamins C and D, selenium, zinc and iron, and have been acknowledged with identifying patients at risk, such as those requiring continuous renal replacement therapy (CRRT). The most important trials and progress in understanding have occurred with vitamin D (25(OH)D), iron and carnitine. Vitamin D blood levels less than 12 ng/ml are associated with poor clinical outcomes: supplementation in deficient ICU patients generates favourable metabolic changes and decreases mortality. Single high-dose 25(OH)D should not be delivered anymore, as boluses induce a negative feedback mechanism causing inhibition of this vitamin. Iron-deficient anaemia is frequent and can be treated safely with high-dose intravenous iron under the guidance of hepcidin to confirm deficiency diagnosis. SUMMARY: The needs in critical illness are higher than those of healthy individuals and must be covered to support immunity. Monitoring selected micronutrients is justified in patients requiring more prolonged ICU therapy. Actual results point towards combinations of essential micronutrients at doses below upper tolerable levels. Finally, the time of high-dose micronutrient monotherapy is probably over.

Association of plasma zinc levels with anti-SARS-CoV-2 IgG and IgA seropositivity in the general population: A case-control study.

INTRODUCTION: Some micronutrients have key roles in immune defence, including mucosal defence mechanisms and immunoglobulin production. Altered micronutrient status has been linked with COVID-19 infection and disease severity. We assessed the associations of selected circulating micronutrients with anti-SARS-CoV-2 IgG and IgA seropositivity in the Swiss community using early pandemic data. METHODS: Case-control study comparing the first PCR-confirmed COVID-19 symptomatic cases in the Vaud Canton (May to June 2020, n = 199) and controls (random population sample, n = 447), seronegative for IgG and IgA. The replication analysis included seropositive (n = 134) and seronegative (n = 152) close contacts from confirmed COVID-19 cases. Anti-SARS-CoV-2 IgG and IgA levels against the native trimeric spike protein were measured using the Luminex immunoassay. We measured plasma Zn, Se and Cu concentrations by ICP-MS, and 25-hydroxy-vitamin D3 (25(OH)D3) with LC-MS/MS and explored associations using multiple logistic regression. RESULTS: The 932 participants (54.1% women) were aged 48.6 ± 20.2 years (±SD), BMI 25.0 ± 4.7 kg/m2 with median C-Reactive Protein 1 mg/l. In logistic regressions, log2(Zn) plasma levels were negatively associated with IgG seropositivity (OR [95% CI]: 0.196 [0.0831; 0.465], P < 0.001; replication analyses: 0.294 [0.0893; 0.968], P < 0.05). Results were similar for IgA. We found no association of Cu, Se, and 25(OH)D3 with anti-SARS-CoV-2 IgG or IgA seropositivity. CONCLUSION: Low plasma Zn levels were associated with higher anti-SARS-CoV-2 IgG and IgA seropositivity in a Swiss population when the initial viral variant was circulating, and no vaccination available. These results suggest that adequate Zn status may play an important role in protecting the general population against SARS-CoV-2 infection. REGISTRY: CORONA IMMUNITAS:: ISRCTN18181860.

Nutritional and metabolic characteristics of critically ill patients admitted for severe toxidermia.

INTRODUCTION: Drug-induced toxidermia is an idiosyncratic adverse skin reaction that may become life-threatening in a small portion of patients, requiring intensive care unit (ICU) admission. The treatment recommendations are extrapolated from those of major burns, while prospective data remain sparse. The objective was to observe the application of these recommendations in patients treated in a burn ICU. METHOD: Retrospective cohort study including patients requiring ICU between 2006 and 2020 in a tertiary university hospital. INCLUSION CRITERIA: Age >18 years. Patients were categorized as Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN), or other toxidermia. VARIABLES: severity scores, body surface area (BSA) involvement, nutritional and metabolic variables, trace element status, outcome variables. Descriptive statistics: median [IQR]. RESULTS: Altogether 35 patients were included (27 SJS/TEN and 8 "other"), aged 58 [48; 69] years. Skin involvement was 45% [30; 60] of body surface, 17 patients required mechanical ventilation, and length of ICU stay was 16 [6.5; 26] days. Hospital mortality was 23%. Fluid resuscitation requirements were moderate, despite intense inflammation (admission CRP (144 [89; 218] mg/L). The first 2 weeks' energy and protein intakes were below recommendations (p < 0.0001), lowest with oral feeding. Indirect calorimetry showed high energy expenditure in 11 patients (30.4 [23.9; 35.5] kcal/kg) resulting in negative energy balances (mean -245 kcal/day). Copper and zinc levels were below reference range during the first week, the low copper values being a novel finding. CONCLUSION: Trace elements should be monitored. The cohort was underfed with intakes lower than our ICU protocols, partly explained by short intubation times, and mucocutaneous involvement complicating the management and placement of feeding tubes. Oral feeding was least efficient and may become an indication for supplemental parenteral nutrition in the absence of an enteral feeding tube. CLINICALTRIALS: gov Identifier: NCT05320653.