Micronutrient deficiency in critical illness: an invisible foe?

Nutrition in the intensive care unit: from the acute phase to beyond

Recent randomized controlled trials (RCTs) have shown no benefit but  dose-dependent harm by early full nutritional support in critically ill patients. Lack of benefit may be explained by anabolic resistance, suppression of cellular repair processes, and aggravation of hyperglycemia and insulin needs. Also early high amino acid doses did not provide benefit, but instead associated with harm in patients with organ dysfunctions. However, most studies focused on nutritional interventions initiated during the first days after intensive care unit admission. Although the intervention window of some RCTs extended into the post-acute phase of critical illness, no large RCTs studied nutritional interventions initiated beyond the first week. Hence, clear evidence-based guidance on when and how to initiate and advance nutrition is lacking. Prolonged underfeeding will come at a price as there is no validated metabolic monitor that indicates readiness for medical nutrition therapy, and an adequate response to nutrition, which likely varies between patients. Also micronutrient status cannot be assessed reliably, as inflammation can cause redistribution, so that plasma micronutrient concentrations are not necessarily reflective of total body stores. Moreover, high doses of individual micronutrients have not proven beneficial. Accordingly, current evidence provides clear guidance on which nutritional strategies to avoid, but the ideal nutritional regimen for individual patients remains unclear. In this narrative review, we summarize the findings of recent studies, discuss possible mechanisms explaining the results, point out pitfalls in interpretation of RCTs and their effect on clinical practice, and formulate suggestions for future research.

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.

Novel dietary strategies to manage sarcopenia

PURPOSE OF REVIEW

Sarcopenia is a wasting disease, mostly age-related in which muscle strength and mass decline, such as physical performance. With aging, both lower dietary protein intake and anabolic resistance lead to sarcopenia. Moreover, aging and sarcopenia display low-grade inflammation, which also worsen muscle condition. In this review, we focused on these two main targets to study dietary strategies.

RECENT FINDINGS

The better understanding in mechanisms involved in sarcopenia helps building combined dietary approaches including physical activity that would slow the disease progression. New approaches include better understanding in the choice of quality proteins, their amount and schedule and the association with antioxidative nutrients.

SUMMARY

First, anabolic resistance can be countered by increasing significantly protein intake. If increasing amount remains insufficient, the evenly delivery protein schedule provides interesting results on muscle strength. Quality of protein is also to consider for decreasing risk for sarcopenia, because varying sources of proteins appears relevant with increasing plant-based proteins ratio. Although new techniques have been developed, as plant-based proteins display a lower availability, we need to ensure an adapted overall amount of proteins. Finally, specific enrichment with leucine from whey protein remains the dietary combined approach most studied and studies on citrulline provide interesting results. As cofactor at the edge between anabolic and antioxidative properties, vitamin D supplementation is to recommend. Antioxidative dietary strategies include both fibers, vitamins, micronutrients and polyphenols from various sources for positive effects on physical performance. The ω 3 -polyunsaturated fatty acids also display positive modifications on body composition. Gut microbiota modifiers, such as prebiotics, are promising pathways to improve muscle mass and function and body composition in sarcopenic patients. Nutritional interventions could be enhanced by combination with physical activity on sarcopenia. In healthy older adults, promoting change in lifestyle to get near a Mediterranean diet could be one of the best options. In sarcopenia adults in which lifestyle changes appears unprobable, specific enrichement potentialized with physical activity will help in the struggle against sarcopenia. Longitudinal data are lacking, which makes it hard to draw strong conclusions. However, the effects of a physical activity combined with a set of nutrition interventions on sarcopenia seems promising.

Nutrition in Critically Ill Children with AKI on Continuous RRT: Consensus Recommendations

BACKGROUND

Nutrition plays a vital role in the outcome of critically ill children, particularly those with AKI. Currently, there are no established guidelines for children with AKI treated with continuous RRT (CRRT). A thorough understanding of the metabolic changes and nutritional challenges in AKI and CRRT is required. Our objective was to create clinical practice points for nutritional assessment and management in critically ill children with AKI receiving CRRT.

METHODS

PubMed, MEDLINE, Cochrane, and Embase databases were searched for articles related to the topic. Expertise of the authors and a consensus of the workgroup were additional sources of data in the article. Available articles on nutrition therapy in pediatric patients receiving CRRT through January 2023.

RESULTS

On the basis of the literature review, the current evidence base was examined by a panel of experts in pediatric nephrology and nutrition. The panel used the literature review as well as their expertise to formulate clinical practice points. The modified Delphi method was used to identify and refine clinical practice points.

CONCLUSIONS

Forty-four clinical practice points are provided on nutrition assessment, determining energy needs, and nutrient intake in children with AKI and on CRRT on the basis of the existing literature and expert opinions of a multidisciplinary panel.

Minerals and Antioxidant Micronutrients Levels and Clinical Outcome in Older Patients Hospitalized for COVID-19 during the First Wave of the Pandemic

Excessive inflammatory response has been implicated in severe respiratory forms of coronavirus disease 2019 (COVID-19). Trace elements such as zinc, selenium, and copper are known to modulate inflammation and immunity. This study aimed to assess the relationships between antioxidant vitamins and mineral trace elements levels as well as COVID-19 severity in older adults hospitalized. In this observational retrospective cohort study, the levels of zinc, selenium, copper, vitamin A, β-carotene, and vitamin E were measured in 94 patients within the first 15 days of hospitalization. The outcomes were in-hospital mortality secondary to COVID-19 or severe COVID-19. A logistic regression analysis was conducted to test whether the levels of vitamins and minerals were independently associated with severity. In this cohort (average age of 78 years), severe forms (46%) were associated with lower zinc (p = 0.012) and β-carotene (p < 0.001) concentrations, and in-hospital mortality (15%) was associated with lower zinc (p = 0.009), selenium (p = 0.014), vitamin A (p = 0.001), and β-carotene (p = 0.002) concentrations. In regression analysis, severe forms remained independently associated with lower zinc (aOR 2.13, p = 0.018) concentrations, and death was associated with lower vitamin A (aOR = 0.165, p = 0.021) concentrations. Low plasma concentrations of zinc and vitamin A were associated with poor prognosis in older people hospitalized with COVID-19.

Pitfalls in the interpretation of blood tests used to assess and monitor micronutrient nutrition status

Assessment of micronutrient (MN) status is of particular importance in patients who require medical nutrition therapy, especially those requiring parenteral nutrition. Blood testing is generally the only tool available in clinical settings to assess MN status. However, using plasma or serum concentration faces pitfalls mainly because of the impact of inflammation that diverts the MNs from the circulating compartment. This review aims to review the blood tests that are useful and provide information about how to integrate functional markers of status to reach a clinically relevant diagnosis. Most impacted, with a significant and proportional decrease in plasma concentrations, are iron, selenium, zinc, thiamin, folic acid, cobalamin, and vitamins A, C, and D; copper is the only MN for which the plasma concentration increases. Therefore, a surrogate marker of inflammation, C-reactive protein, must always be determined simultaneously. Validated intracellular and functional tests are proposed to improve status assessment. A protocol is suggested for tests required both on commencing and during nutrition support. A timely turnaround of analysis is essential for results to be clinically useful. In some cases, the appropriate provision of MNs should be commenced before results have been obtained to confirm the clinical assessment. Laboratory tests of MN status are an area prone to misuse and misinterpretation. The appropriate use and interpretation of such tests are essential to ensure the correct management of nutrition problems.

The emerging roles of next-generation metabolomics in critical care nutrition

Critical illness leads to millions of deaths worldwide each year, with a significant surge due to the COVID-19 pandemic. Patients with critical illness are frequently associated with systemic metabolic disorders and malnutrition. The idea of intervention for critically ill patients through enteral and parenteral nutrition has been paid more and more attention gradually. However, current nutritional therapies focus on evidence-based practice, and there have been lacking holistic approaches for nutritional support assessment. Metabolomics is a well-established omics technique in system biology that enables comprehensive profiling of metabolites in a biological system and thus provides the underlying information expressed and modulated by all other omics layers. In recent years, with the development of high-resolution and accurate mass spectrometry, metabolomics entered a new "generation", promoting its broader applications in critical care nutrition. In this review, we first described the technological development and milestones of next-generation metabolomics in the past 20 years. We then discussed the emerging roles of next-generation metabolomics in advancing our understanding of critical care nutrition, such as nutritional deficiency risk evaluation, metabolic mechanisms of nutritional therapies, and novel nutrition target identification.

ESPEN micronutrient guideline

BACKGROUND

Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. Recent research has shown the importance of MNs in common pathologies, with significant deficiencies impacting the outcome.

OBJECTIVE

This guideline aims to provide information for daily clinical nutrition practice regarding assessment of MN status, monitoring, and prescription. It proposes a consensus terminology, since many words are used imprecisely, resulting in confusion. This is particularly true for the words "deficiency", "repletion", "complement", and "supplement".

METHODS

The expert group attempted to apply the 2015 standard operating procedures (SOP) for ESPEN which focuses on disease. However, this approach could not be applied due to the multiple diseases requiring clinical nutrition resulting in one text for each MN, rather than for diseases. An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL. The search focused on physiological data, historical evidence (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

There was a limited number of interventional trials, preventing meta-analysis and leading to a low level of evidence. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90% of votes. Altogether the guideline proposes sets of recommendations for 26 MNs, resulting in 170 single recommendations. Critical MNs were identified with deficiencies being present in numerous acute and chronic diseases. Monitoring and management strategies are proposed.

CONCLUSION

This guideline should enable addressing suboptimal and deficient status of a bundle of MNs in at-risk diseases. In particular, it offers practical advice on MN provision and monitoring during nutritional support.

Management of moderate to severe traumatic brain injury: an update for the intensivist

Traumatic brain injury (TBI) remains one of the most fatal and debilitating conditions in the world. Current clinical management in severe TBI patients is mainly concerned with reducing secondary insults and optimizing the balance between substrate delivery and consumption. Over the past decades, multimodality monitoring has become more widely available, and clinical management protocols have been published that recommend potential interventions to correct pathophysiological derangements. Even while evidence from randomized clinical trials is still lacking for many of the recommended interventions, these protocols and algorithms can be useful to define a clear standard of therapy where novel interventions can be added or be compared to. Over the past decade, more attention has been paid to holistic management, in which hemodynamic, respiratory, inflammatory or coagulation disturbances are detected and treated accordingly. Considerable variability with regards to the trajectories of recovery exists. Even while most of the recovery occurs in the first months after TBI, substantial changes may still occur in a later phase. Neuroprognostication is challenging in these patients, where a risk of self-fulfilling prophecies is a matter of concern. The present article provides a comprehensive and practical review of the current best practice in clinical management and long-term outcomes of moderate to severe TBI in adult patients admitted to the intensive care unit.

Clinical nutrition approach in medical management of COVID-19 hospitalized patients: A narrative review

Background:

Malnutrition in COVID-19 hospitalized patients is associated with a high-risk condition to increase disease severity and prolonging the recovery period. Therefore, nutritional therapy, including supplements plays a critical role to reduce disease-related complications and the length of hospital stay.

Aim:

To review the latest evidence on nutritional management options in COVID-19 hospitalized patients, as well as possibly prescribed supplements. Methods: This review was conducted by considering the latest recommendations, using the guidelines of the American Society of Enteral and Parenteral (ASPEN) and the European Society of Enteral and Parenteral (ESPEN), and searching Web of Science, PubMed/Medline, ISI, and Medline databases. The relevant articles were found using a mix of related mesh terms and keywords. We attempted to cover all elements of COVID-19 hospitalized patients’ dietary management. Results: Energy demand in COVID-19 patients is a vital issue. Indirect Calorimetry (IC) is the recommended method to measure resting energy expenditure. However, in the absence of IC, predictive equations may be used. The ratio of administered diet for the macronutrients could be based on the phase and severity of Covid-19 disease. Moreover, there are recommendations for taking micronutrient supplements with known effects on improving the immune system or reducing inflammation. Conclusions: Nutritional treatment of COVID-19 patients in hospitals seems to be an important element of their medical care. Enteral nutrition would be the recommended feeding method for early nutrition support. However, data in the COVID-19 nutritional domain relating to micronutrient supplementation are still fragmentary and disputed, and further study is required.

A guide to enteral nutrition in intensive care units: 10 expert tips for the daily practice

The preferential use of the oral/enteral route in critically ill patients over gut rest is uniformly recommended and applied. This article provides practical guidance on enteral nutrition in compliance with recent American and European guidelines. Low-dose enteral nutrition can be safely started within 48 h after admission, even during treatment with small or moderate doses of vasopressor agents. A percutaneous access should be used when enteral nutrition is anticipated for ≥ 4 weeks. Energy delivery should not be calculated to match energy expenditure before day 4–7, and the use of energy-dense formulas can be restricted to cases of inability to tolerate full-volume isocaloric enteral nutrition or to patients who require fluid restriction. Low-dose protein (max 0.8 g/kg/day) can be provided during the early phase of critical illness, while a protein target of > 1.2 g/kg/day could be considered during the rehabilitation phase. The occurrence of refeeding syndrome should be assessed by daily measurement of plasma phosphate, and a phosphate drop of 30% should be managed by reduction of enteral feeding rate and high-dose thiamine. Vomiting and increased gastric residual volume may indicate gastric intolerance, while sudden abdominal pain, distension, gastrointestinal paralysis, or rising abdominal pressure may indicate lower gastrointestinal intolerance.

Micronutrient intake from enteral nutrition in critically ill adult patients: A retrospective observational study

OBJECTIVE

The objective of this study was to determine the intake of micronutrients including vitamins B₁₂, D, C, and A; folate; thiamine; iron; zinc; and selenium that are delivered from enteral nutrition (EN) during routine clinical practice in critically ill adults, expressed as a percentage of the Australia and New Zealand nutrient reference values.

METHODS

This single-center retrospective observational study was conducted in Melbourne, Australia during the first 7 d of intensive care unit admission. Mechanically ventilated patients prescribed exclusive EN were considered for inclusion. The primary and secondary outcomes were micronutrient intake expressed as a percentage of the recommended dietary intake (daily intake intended to meet the needs of 97% to 98% of a healthy population) and the upper level of intake (highest daily intake unlikely to pose adverse health effects), respectively. Data are presented as mean (SD) or median [interquartile range].

RESULTS

In total, 57 patients were included (62 (16) y, 67% male). EN was delivered for 5 [4-6] d, with 47% (20) energy adequacy achieved. EN delivery met the recommended dietary intake for vitamin B₁₂, vitamin C, thiamine, and iron and did not meet the recommended dietary intake for vitamin D, vitamin A, folate, zinc, and selenium. No micronutrients exceeded the upper level of intake.

CONCLUSION

EN delivery met the recommended intake for four micronutrients, did not meet the recommended intake for five micronutrients, and did not exceed the upper level of intake for any micronutrient when approximately 50% energy adequacy was achieved types.

Micronutrient intake from enteral nutrition in critically ill adults: A systematic review of randomised controlled trials

OBJECTIVES

The primary objective was to compare the intake of important micronutrients provided from enteral nutrition to critically ill patients with the Australia and New Zealand recommended dietary intakes. A secondary objective was to compare the upper levels of intake and investigate prespecified subgroups.

REVIEW METHOD USED

A systematic literature review was performed.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, and CENTRAL were used.

REVIEW METHODS

Databases were searched for randomised controlled trials that investigated an enteral nutrition intervention as the sole source of nutrition, were published in English between January 2000 and January 8th, 2021, and provided data to calculate micronutrient intake. The primary outcome was the % recommended dietary intake. The quality of individual trials was assessed using the Cochrane Risk of Bias Tool. Outcomes are presented as either mean ± standard deviation or median [interquartile range], with a p < 0.05 considered statistically significant.

RESULTS

Thirteen trials were included (n = 1538 patients). Trials investigating hypocaloric nutrition were excluded from the primary outcome assessment (conducted in nine trials (n = 1220)). All nine trials delivered ≥104% of the recommended dietary intakes and <100% of the upper level of intakes of all micronutrients. In subgroup analyses, trials with ≥80% target energy delivered a higher % of the recommended dietary intake of vitamin B12, thiamine, zinc, and vitamin C. Acute Physiology and Chronic Health Evaluation scores ≥20 delivered a higher % of the recommended dietary intake of vitamin B12 and vitamin A. Antioxidant formulas compared with standard formulas delivered a higher % recommended dietary intake of vitamin C and thiamine. In the four trials that investigated hypocaloric feeding compared with control, there was no difference in micronutrient intake. The quality was low.

CONCLUSIONS

Enteral nutrition delivery frequently met the recommended dietary intakes for all micronutrients investigated and did not exceed the upper levels of intake set for health.

PROSPERO REGISTRATION

CRD42020178333.

The redox signal: A physiological perspective

A signal in biology is any kind of coded message sent from one place in an organism to another place. Biology is rich in claims that reactive oxygen and nitrogen species transmit signals. Therefore, we define a "redox signal as an increase/decrease in the level of reactive species". First, as in most biology disciplines, to analyze a redox signal you need first to deconstruct it. The essential components that constitute a redox signal and should be characterized are: (i) the reactivity of the specific reactive species, (ii) the magnitude of change, (iii) the temporal pattern of change, and (iv) the antioxidant condition. Second, to be able to translate the physiological fate of a redox signal you need to apply novel and bioplausible methodological strategies. Important considerations that should be taken into account when designing an experiment is to (i) assure that redox and physiological measurements are at the same or similar level of biological organization and (ii) focus on molecules that are at the highest level of the redox hierarchy. Third, to reconstruct the redox signal and make sense of the chaotic nature of redox processes, it is essential to apply mathematical and computational modeling. The aim of the present study was to collectively present, for the first time, those elements that essentially affect the redox signal as well as to emphasize that the deconstructing, decoding and reconstructing of a redox signal should be acknowledged as central to design better studies and to advance our understanding on its physiological effects.

Low Levels of Few Micronutrients May Impact COVID-19 Disease Progression: An Observational Study on the First Wave

We report an observational study performed between March and May 2020 in a Spanish university hospital during the SARS-CoV-2 pandemic. The main objective was to analyse the association between the levels of micronutrients in severe COVID-19 patients and their outcome. Adult patients with a positive polymerase-chain-reaction (PCR) for SARS-CoV-2 in the nasopharyngeal swab or in tracheal aspirate culture in the case of intubation were included. Micronutrient data were obtained from plasma analysis of a standard nutritional assessment performed within the first 24 h of hospital admission. Vitamins A, B₆, C and E were analysed with HPLC methods; 25-OH-vitamin D by immunoassay and zinc by colorimetric measurements. One hundred and twenty patients were included. We found that 74.2% patients had low levels of zinc (normal levels >84 µg/dL) with a mean value of 63.5 (SD 13.5); 71.7% patients had low levels of vitamin A (normal levels >0.3 mg/L) with a mean value of 0.17 (SD 0.06); 42.5% patients had low levels of vitamin B₆ (normal levels >3.6 ng/mL) with a mean value of 2.2 (SD 0.9); 100% patients had low levels of vitamin C (normal levels >0.4 mg/dL) with a mean value of 0.14 (SD 0.05); 74.3% patients had low values of vitamin D (normal levels >20 ng/mL) with mean value of 11.4 (SD 4.3); but only 5.8% of patients had low levels of vitamin E (normal levels >5 mg/L) with a mean value of 3.95 (SD 0.87). The variables associated with the need for ICU admission were low levels of zinc (standard error 0.566, 95% CI 0.086 to 0.790, p = 0.017), low levels of vitamin A (standard error 0.582, 95% CI 0.061 to 0.594, p = 0.004), age over 65 (standard error 0.018, 95% CI 0.917 to 0.985, p = 0.005) and male gender (standard error 0.458, 95% CI 1.004 to 6.040, p = 0.049). The only variable that was independently associated with the need for orotracheal intubation was low levels of vitamin A (standard error 0.58, 95% CI 0.042 to 0.405, p = 0.000). Conclusions: Low levels of vitamin A and zinc are associated with a greater need for admission to the ICU and orotracheal intubation. Patients older than 65 years had higher mortality. Randomized clinical trials are needed to examine whether micronutrient supplementation could be beneficial as an adjunctive treatment in COVID-19.

Micronutrients early in critical illness, selective or generous, enteral or intravenous?

PURPOSE OF REVIEW

Micronutrients have essential antioxidant and immune functions, while low blood concentrations are frequently observed in critically ill patients. This has led to the concepts of complementation, repletion, or even pharmacological supplementation. Over the last three decades, many clinical studies have tested the latter strategy, with controversial or negative results. Therefore, this review aims at evaluating micronutrient-related interventions that are mandatory or need to be assessed in future trials or clinical registries in all or specific critically ill patients.

RECENT FINDINGS

In the critically ill, low plasma/serum micronutrient levels not always reflect a true deficiency in the absence of demonstrable losses. Current practices of micronutrient provision and monitoring in critical care, vary substantially across the world. Also, recent clinical trials testing high dose as monotherapy (selenium, thiamine, vitamin C, vitamin D) or in combination have failed to demonstrate clinical benefits in sepsis. However, these studies have not applied a physiological integrative approach of micronutrient action.

SUMMARY

Micronutrients are essential in nutrition but their administration and monitoring are difficult. So far, different well designed RCTs on intravenous and oral high dose micronutrient supplementation have been conducted. Nevertheless, very high-dose single micronutrients cannot be advocated at this stage in sepsis, or any other critical condition. By contrast, studies using combination of moderate doses of micronutrients in specific diseases, such as burns and trauma have been associated with improved outcomes. Intravenous administration seems to be the most efficient route. Future clinical trials need to integrate the physiology underlying the interconnected micronutrient activity, and choose more specific primary and secondary endpoints.

Oral Nutrition during and after Critical Illness: SPICES for Quality of Care!

Malnutrition is associated to poor outcomes in critically ill patients. Oral nutrition is the route of feeding in less than half of the patients during the intensive care unit (ICU) stay and in the majority of ICU survivors. There are growing data indicating that insufficient and/or inadequate intakes in macronutrients and micronutrients are prevalent within these populations. The present narrative review focuses on barriers to food intakes and considers the different points that should be addressed in order to optimize oral intakes, both during and after ICU stay. They are gathered in the SPICES concept, which should help ICU teams improve the quality of nutrition care following 5 themes: swallowing disorders screening and management, patient global status overview, involvement of dieticians and nutritionists, clinical evaluation of nutritional intakes and outcomes, and finally, supplementation in macro-or micronutrients.

Monitoring and parenteral administration of micronutrients, phosphate and magnesium in critically ill patients: The VITA-TRACE survey

BACKGROUND & AIMS

Despite the presumed importance of preventing and treating micronutrient and mineral deficiencies, it is still not clear how to optimize measurement and administration in critically ill patients. In order to design future comparative trials aimed at optimizing micronutrient and mineral management, an important first step is to gain insight in the current practice of micronutrient, phosphate and magnesium monitoring and administration.

METHODS

Within the metabolism-endocrinology-nutrition (MEN) section of the European Society of Intensive Care Medicine (ESICM), the micronutrient working group designed a survey addressing current practice in parenteral micronutrient and mineral administration and monitoring. Invitations were sent by the ESICM research department to all ESICM members and past members.

RESULTS

Three hundred thirty-four respondents completed the survey, predominantly consisting of physicians (321 [96.1%]) and participants working in Europe (262 [78.4%]). Eighty-one (24.3%) respondents reported to monitor micronutrient deficiencies through clinical signs and/or laboratory abnormalities, and 148 (44.3%) reportedly measure blood micronutrient concentrations on a routine basis. Two hundred ninety-two (87.4%) participants provided specific data on parenteral micronutrient supplementation, of whom 150 (51.4%) reported early administration of combined multivitamin and trace element preparations at least in selected patients. Among specific parenteral micronutrient preparations, thiamine (146 [50.0%]) was reported to be the most frequently administered micronutrient, followed by vitamin B complex (104 [35.6%]) and folic acid (86 [29.5%]). One hundred twenty (35.9%) and 113 (33.8%) participants reported to perform daily measurements of phosphate and magnesium, respectively, whereas 173 (59.2%) and 185 (63.4%) reported to routinely supplement these minerals parenterally.

CONCLUSION

The survey revealed a wide variation in current practices of micronutrient, phosphate and magnesium measurement and parenteral administration, suggesting a risk of insufficient prevention, diagnosis and treatment of deficiencies. These results provide the context for future comparative studies, and identify areas for knowledge translation and recommendations.

Micronutrient status during paediatric critical illness: A scoping review

Background

No evidence based recommendations for micronutrient requirements during paediatric critical illness are available, other than those arising from recommended nutrient intakes (RNI) for healthy children and expert opinion.

Objectives

The objective of this review is to examine the available evidence from micronutrient status in critically ill children considering studies which describe 1) micronutrient levels, 2) associations between micronutrient levels and clinical outcome, and 3) impact on clinical outcome with micronutrient supplementation during PICU admission.

Design

Scoping review.

Eligibility criteria

Any study which used a qualitative and quantitative design considering causes and consequences of micronutrient levels or micronutrient supplementation during paediatric critical illness.

Sources of evidence

NICE Healthcare Databases Advanced Search website (https://hdas.nice.org.uk/) was used as a tool for multiple searches, with a content analysis and charting of data extracted.

Results

711 records were identified, 35 were included in the review. Studies evaluated serum micronutrient status was determined on admission day in majority of patients. A content analysis identified (n = 49) initial codes, (n = 14) sub-categories and (n = 5) overarching themes during critical illness, which were identified as: i) low levels of micronutrients, ii) causes of aberrant micronutrient levels, iii) associations between micronutrients levels and outcome, iv) supplementation of micronutrients.

Conclusion

During critical illness, micronutrients should be provided in sufficient amounts to meet reference nutrient intakes for age. Although, there is insufficient data to recommend routine supplementations of micronutrients at higher doses during critical illness, the ‘absence of evidence should not imply evidence of absence’, and well designed prospective studies are urgently needed to elucidate paediatric micronutrient requirements during critical illness. The absence of reliable biomarkers make it challenging to determine whether low serum levels are reflective of a true deficiency or as a result redistribution, particularly during the acute phase of critical illness. As more children continue to survive a PICU admission, particularly those with complex diseases micronutrient supplementation research should also be inclusive of the recovery phase following critical illness.

ICU-acquired weakness

Critically ill patients often acquire neuropathy and/or myopathy labeled ICU-acquired weakness. The current insights into incidence, pathophysiology, diagnostic tools, risk factors, short- and long-term consequences and management of ICU-acquired weakness are narratively reviewed. PubMed was searched for combinations of “neuropathy”, “myopathy”, “neuromyopathy”, or “weakness” with “critical illness”, “critically ill”, “ICU”, “PICU”, “sepsis” or “burn”. ICU-acquired weakness affects limb and respiratory muscles with a widely varying prevalence depending on the study population. Pathophysiology remains incompletely understood but comprises complex structural/functional alterations within myofibers and neurons. Clinical and electrophysiological tools are used for diagnosis, each with advantages and limitations. Risk factors include age, weight, comorbidities, illness severity, organ failure, exposure to drugs negatively affecting myofibers and neurons, immobility and other intensive care-related factors. ICU-acquired weakness increases risk of in-ICU, in-hospital and long-term mortality, duration of mechanical ventilation and of hospitalization and augments healthcare-related costs, increases likelihood of prolonged care in rehabilitation centers and reduces physical function and quality of life in the long term. RCTs have shown preventive impact of avoiding hyperglycemia, of omitting early parenteral nutrition use and of minimizing sedation. Results of studies investigating the impact of early mobilization, neuromuscular electrical stimulation and of pharmacological interventions were inconsistent, with recent systematic reviews/meta-analyses revealing no or only low-quality evidence for benefit. ICU-acquired weakness predisposes to adverse short- and long-term outcomes. Only a few preventive, but no therapeutic, strategies exist. Further mechanistic research is needed to identify new targets for interventions to be tested in adequately powered RCTs.