Permissive Underfeeding or Standard Enteral Feeding in High- and Low-Nutritional-Risk Critically Ill Adults. Post Hoc Analysis of the PermiT Trial

The Role of Serum Albumin and Secretory Phospholipase A2 in Sepsis

Sepsis is caused by a dysregulated host response to an infection that leads to cascading cell death and eventually organ failure. In this study, the role of inflammatory response serum secretory phospholipase A2 (sPLA2) and albumin in sepsis was investigated by determining the activities of the two proteins in serial serum samples collected on different days from patients with sepsis after enrollment in the permissive underfeeding versus standard enteral feeding protocols in an intensive care unit. Serum sPLA2 and albumin showed an inverse relationship with increasing sPLA2 activity and decreasing albumin membrane-binding activity in patients with evolving complications of sepsis. The activities of sPLA2 and albumin returned to normal values more rapidly in the permissive underfeeding group than in the standard enteral feeding group. The inverse sPLA2-albumin activity relationship suggests a complex interplay between these two proteins and a regulatory mechanism underlying cell membrane phospholipid homeostasis in sepsis. The decreased albumin-membrane binding activity in patients' serum was due to its fatty acid-binding sites occupied by pre-bound fatty acids that might alter albumin's structure, binding capacities, and essential functions. The sPLA2-albumin dual serum assays may be useful in determining whether nutritional intervention effectively supports the more rapid recovery of appropriate immune responses in critically ill patients with sepsis.

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.

Comparative efficacy of peptide-based versus standard polymeric enteral nutrition in ICU patients at high nutritional risk: a multicenter randomized controlled trial

Within intensive care units (ICU), the administration of peptide-based formulas (PBF) may confer nutritional advantages for critically ill patients identified with heightened nutritional risk. This investigation aimed to ascertain the efficacy of PBF in comparison to standard polymeric formulas (SPF) among this patient cohort. A double-blind, randomized controlled trial was conducted across three ICUs, encompassing 63 adult patients characterized by elevated modified Nutrition Risk in Critically Ill (mNUTRIC) scores. Enrollment occurred promptly subsequent to ICU admission, with participants allocated to receive either PBF or SPF. Primary outcome was the duration to achieve caloric targets. Secondary outcomes involved the evaluation of mean daily gastric residual volume, mechanical ventilation period, infection rates within the ICU, length of hospitalization, mortality rates, nutritional status and inflammatory markers, specifically serum albumin and interleukin-6 levels. Patients in the PBF group reached their caloric targets more expeditiously compared to the SPF group (2.06 ± 0.43 days versus 2.39 ± 0.79 days; p = 0.03). No significant differences were discernible between the groups regarding gastric residual volume, duration of mechanical ventilation, ICU length of stay, mortality, or infection rates. Both cohorts exhibited minimal adverse effects and were devoid of any instances of abdominal distension. While not reaching statistical significance, the observed trends in albumin and interleukin-6 levels suggest a potential advantage of PBF utilization. The implementation of PBF enabled swifter attainment of caloric goals in ICU patients at high nutritional risk without adversely impacting other clinical parameters. Given its favorable tolerance profile and potential immunomodulatory properties, PBF may be considered a valuable nutritional intervention in this setting.Thai Clinical Trials Registry TCTR20220221006. Registered 21 February 2022, https://www.thaiclinicaltrials.org/show/TCTR20220221006 .

Association of energy delivery with short-term survival in mechanically ventilated critically ill adult patients: a secondary analysis of the NEED trial

BACKGROUND AND AIMS

The optimal energy delivery for mechanically ventilated patients is controversial, particularly during the first week of ICU admission. This study aimed to investigate the association between different caloric adequacy and 28-day mortality in a cohort of critically ill adults on mechanical ventilation.

METHODS

This is a secondary analysis of a multicenter, cluster-randomized controlled trial. Eligible patients were divided into four quartiles (Q1-Q4) according to caloric adequacy calculated by the actual average daily energy delivery during the first seven days of ICU stay divided by energy requirement as a percentage. Cox proportional hazards models were used to examine the impact of different quartiles of caloric adequacy on 28-day mortality in the whole cohort and subgroups with different nutritional risk status at enrollment.

RESULTS

A total of 1587 patients were included in this study, with an overall 28-day mortality of 15.8%. The average caloric adequacy was 26.3 ± 11.9% (Q1), 52.5 ± 5.5% (Q2), 71.7 ± 6.4% (Q3), 107.0 ± 22.2% (Q4), respectively (p < 0.001 among quartiles). Compared with Q1, Q3 was associated with lower mortality in the unadjusted model (hazard ratio [HR] = 0.536; 95% confidence interval [CI], 0.375-0.767; P = 0.001) and adjusted model (adjusted HR = 0.508; 95% CI, 0.339-0.761; P = 0.001). This association remained valid in the subgroup of high nutritional risk patients (unadjusted HR = 0.387; 95% CI, 0.238-0.627; P < 0.001 and adjusted HR = 0.369; 95% CI, 0.216-0.630; P < 0.001, respectively), but not in those with low risk.

CONCLUSIONS

Energy delivery near the 70% energy requirements in the first week of ICU stay was associated with reduced 28-day mortality among mechanically ventilated critically ill patients, especially in patients with high nutrition risk at admission.

[High nutritional risk by three variants of NUTRIC score in critically ventilated patients]

Introduction

Introduction: variants of the NUTRIC score with or without inflammatory biomarkers, modified without interleukin 6 (IL-6) (NUTRICm), with C-reactive protein (CRP) instead of IL-6, dichotomous (NUTRICpcr1) or in tertiles (NUTRICpcr2), were proposed to assess nutritional risk (NR) in critical patients. However, the assessment of the high NR might not be uniform between these scores. Objectives: to compare the assessment of the high NR by NUTRICm and the two variants of the NUTRICpcr. Material and methods: analysis of a prospective cohort of patients ventilated prior to COVID-19. Agreement was analyzed using the Kappa test and mortality discrimination by logistic regression. The proportion of patients with high NR was compared with the Chi-square test. Results: five hundred and fifty patients were analyzed. Median (IQR) age and APACHE II: 44 (28-58) years and 17 (12-22) points, predominant traumatic pathology (38.2 %) and Intensive Care Unit (ICU) mortality of 32.5 %. The concordance was high between NUTRICm and NUTRICpcr1 (Kappa = 0.81) and lower between NUTRICm and NUTRICpcr2 (Kappa = 0.60). The AUCROC (95 % CI) of NUTRICm, NUTRICpcr1 and NUTRICpcr2 to discriminate mortality was 0.695 (0.495-0.591), 0.693 (0.495-0.591) and 0.685 (0.495-0.591), respectively. The tall NB showed significant differences between NUTRICm and NUTRICpcr1 (19.8 % vs 14.4 %, p 0.0243), being greater between NUTRICm and NUTRICpcr2 (19.8 vs 9.8 %, p < 0.0001). Conclusion: the three NUTRIC variants studied discriminate mortality in a similar way. However, the NUTRICm, without an inflammatory biomarker, classifies more patients as high nutritional risk.

Modified Nutrition Risk in the Critically ill score and mortality in critically ill patients with traumatic brain injury

BACKGROUND

Understanding the relationship between nutrition risk at admission to the intensive care unit (ICU) and the prognosis of patients with traumatic brain injury (TBI) may aid early recognition of high-risk patients.

METHODS

We extracted data from the Medical Information Mart for Intensive Care III and the electronic ICU Collaborative Research Databases. Using modified Nutrition Risk in the Critically ill score (mNUTRIC) within the first 24 h of ICU admission, 5153 patients were divided into three groups: low (≤1, n = 1765), moderate (2-4, n = 2574), and high (≥5, n = 814). The primary outcome was 28-day in-hospital mortality, and the secondary outcomes were 7-day in-hospital mortality, length of ICU stay, and duration of mechanical ventilation.

RESULTS

During the median follow-up time of 6.69 days, 647 deaths occurred in total. After adjustment for potential confounding factors, setting the low mNUTRIC group as a reference, the risk of 28-day mortality was increased in the high and moderate mNUTRIC groups (hazard ratio [HR]high vs low [95% CI]: 4.21 [2.70-6.58] and 2.84 [1.95-4.14], respectively). Similarly, high and moderate mNUTRIC scores are linked to a higher risk of 7-day mortality (PTrend  < 0.001) and a longer duration of mechanical ventilation (PTrend  < 0.001). The effect of mNUTRIC on mortality varied by serum glucose level (PInteraction  = 0.01). Lastly, those whose mNUTRIC scores deteriorated within the first 3 days have a 1.46 times greater risk of dying compared with patients with improved mNUTRIC scores.

CONCLUSIONS

Nutrition risk screening by mNUTRIC score at the time of admission to the ICU may improve mortality prediction.

Body composition and muscle strength at the end of ICU stay are associated with 1-year mortality, a prospective multicenter observational study

BACKGROUND & AIMS

After a prolonged intensive care unit (ICU) stay patients experience increased mortality and morbidity. The primary aim of this study was to assess the prognostic value of nutritional status, body mass composition and muscle strength, as assessed by body mass index (BMI), bioelectrical impedance analysis (BIA), handgrip (HG) test, and that of the biological features to predict one-year survival at the end of a prolonged ICU stay.

METHODS

This was a multicenter prospective observational study. Survivor patients older than 18 years with ICU length of stay >72 h were eligible for inclusion. BIA and HG were performed at the end of the ICU stay. Malnutrition was defined by BMI and fat-free mass index (FFMI). The primary endpoint was one-year mortality. Multivariable logistic regression was performed to determine parameters associated with mortality.

RESULTS

572 patients were included with a median age of 63 years [53.5; 71.1], BMI of 26.6 kg/m2 [22.8; 31.3], SAPS II score of 43 [31; 58], and ICU length of stay of 9 days [6; 15]. Malnutrition was observed in 142 (24.9%) patients. During the 1-year follow-up after discharge, 96 (18.5%) patients died. After adjustment, a low HG test score (aOR = 1.44 [1.11; 1.89], p = 0.01) was associated with 1-year mortality. Patients with low HG score, malnutrition, and Albuminemia <30 g/L had a one-year death rate of 41.4%. Conversely, patients with none of these parameters had a 1-year death rate of 4.1%.

CONCLUSION

BIA to assess FFMI, HG and albuminemia at the end of ICU stay could be used to predict 1-year mortality. Their ability to identify patients eligible for a structured recovery program could be studied.

Isocaloric nutritional support reduces ventilator duration time in major trauma patients

AIMS

Major trauma patients need adequate nutrition for recovery. This study aimed to evaluate the adequacy of nutritional supply and the correlation between nutritional supply and clinical outcome.

METHODS

A single-centre retrospective observational study was undertaken, describing the amounts of energy and proteins provided to 320 critically ill trauma patients during the first 10 days after admission. The data were collected from the electronic medical records of patients admitted to the trauma intensive care unit during the study period and descriptive statistical analyses were performed with the SPSS software.

RESULTS

The mean proportion of supplied energy to recommended energy during the first 10 days after admission was 57.5%, and the mean percentage of supplied protein to recommended protein intake was 51.3%. The patients were divided into those who received ≥70% (isocaloric nutrition group) and those who received <70% (hypocaloric nutrition group) of their estimated requirements. Both the duration of ventilator use (12.7 ± 10.5 vs. 16.0 ± 15.8 days, respectively, p = 0.009) and duration of parenteral nutrition (1.1 ± 1.4 vs. 2.0 ± 2.0 days, respectively, p = 0.001) were shorter in the isocaloric nutrition group (n = 83) than in the hypocaloric nutrition group (n = 237).

CONCLUSION

Total energy and the amount of protein supplied were insufficient compared to the recommended amount. The duration of ventilator use was shorter in the isocaloric nutrition group than in the hypocaloric nutrition group. The association between shortened ventilator use and isocaloric nutrition requires further investigation as a potential intervention to reduce the risk of complications such as ventilator-related pneumonia.

Using Body Composition Analysis for Improved Nutritional Intervention in Septic Patients: A Prospective Interventional Study

The study aimed to determine whether using body composition data acquired through bio-electrical impedance analysis (BIA) to adjust diet formulas could improve outcomes in septic patients. There were 132 septic patients in medical intensive care units enrolled in the prospective, randomized, double-blind, interventional study. For the intervention group, dietitians had access to BIA data for adjusting diet formulas according to body composition variables on days 1, 3, and 8. The patients were also stratified based on nutritional risk using the modified Nutrition Risk in Critically ill (mNUTRIC) score. Patients with intervention were more likely to achieve caloric and protein intake goals compared to the control group, especially in the low-risk group. The intervention did not significantly affect mortality, but the survival curves suggested potential benefits. The high-risk group had longer ICU stays and mechanical ventilation duration, which were mitigated by the intervention. Certain body composition variables (e.g., extracellular water to total body water ratio and phase angle) showed differences between high-risk and low-risk groups and may be related to patient outcomes. Non-invasive body composition assessment using BIA can help dietitians adjust diet formulas for critically ill septic patients. Body composition variables may be associated with sepsis outcomes, but further research with larger patient numbers is needed to confirm these findings.

Metabolic Support in Acute Respiratory Distress Syndrome: A Narrative Review

Nutritional support for acute respiratory distress syndrome (ARDS) patients shares metabolic notions common to other critically ill conditions. Nevertheless, it generates specific concern regarding the primary limitation of oxygen supply and the complications of carbon dioxide elimination, as well as the significant metabolic alterations due to the body's response to illness. In the present narrative review, after briefly summarizing the pathophysiology of critical illness stress response and patients' metabolic requirements, we focus on describing the characteristics of metabolic and artificial nutrition in patients with acute respiratory failure. In patients with ARDS, several aspects of metabolism assume special importance. The physiological effects of substrate metabolism are described for this setting, particularly regarding energy consumption, diet-induced thermogenesis, and the price of their clearance, transformation, and storage. Moreover, we review the possible direct effects of macronutrients on lung tissue viability during ARDS. Finally, we summarize the noteworthy characteristics of metabolic control in critically ill patients with ARDS and offer a suggestion as to the ideal methods of metabolic support for this problem.

Inflammation and Nutrition: Friend or Foe?

The importance of the interplay between inflammation and nutrition has generated much interest in recent times. Inflammation has been identified as a key driver for disease-related malnutrition, leading to anorexia, reduced food intake, muscle catabolism, and insulin resistance, which are stimulating a catabolic state. Interesting recent data suggest that inflammation also modulates the response to nutritional treatment. Studies have demonstrated that patients with high inflammation show no response to nutritional interventions, while patients with lower levels of inflammation do. This may explain the contradictory results of nutritional trials to date. Several studies of heterogeneous patient populations, or in the critically ill or advanced cancer patients, have not found significant benefits on clinical outcome. Vice versa, several dietary patterns and nutrients with pro- or anti-inflammatory properties have been identified, demonstrating that nutrition influences inflammation. Within this review, we summarize and discuss recent advances in both the role of inflammation in malnutrition and the effect of nutrition on inflammation.

Toward nutrition improving outcome of critically ill patients: How to interpret recent feeding RCTs?

Although numerous observational studies associated underfeeding with poor outcome, recent randomized controlled trials (RCTs) have shown that early full nutritional support does not benefit critically ill patients and may induce dose-dependent harm. Some researchers have suggested that the absence of benefit in RCTs may be attributed to overrepresentation of patients deemed at low nutritional risk, or to a too low amino acid versus non-protein energy dose in the nutritional formula. However, these hypotheses have not been confirmed by strong evidence. RCTs have not revealed any subgroup benefiting from early full nutritional support, nor benefit from increased amino acid doses or from indirect calorimetry-based energy dosing targeted at 100% of energy expenditure. Mechanistic studies attributed the absence of benefit of early feeding to anabolic resistance and futile catabolism of extra provided amino acids, and to feeding-induced suppression of recovery-enhancing pathways such as autophagy and ketogenesis, which opened perspectives for fasting-mimicking diets and ketone supplementation. Yet, the presence or absence of an anabolic response to feeding cannot be predicted or monitored and likely differs over time and among patients. In the absence of such monitor, the value of indirect calorimetry seems obscure, especially in the acute phase of illness. Until now, large feeding RCTs have focused on interventions that were initiated in the first week of critical illness. There are no large RCTs that investigated the impact of different feeding strategies initiated after the acute phase and continued after discharge from the intensive care unit in patients recovering from critical illness.

Association between early nutrition support and 28-day mortality in critically ill patients: the FRANS prospective nutrition cohort study

BACKGROUND

Current guidelines suggest the introduction of early nutrition support within the first 48 h of admission to the intensive care unit (ICU) for patients who cannot eat. In that context, we aimed to describe nutrition practices in the ICU and study the association between the introduction of early nutrition support (< 48 h) in the ICU and patient mortality at day 28 (D28) using data from a multicentre prospective cohort.

METHODS

The 'French-Speaking ICU Nutritional Survey' (FRANS) study was conducted in 26 ICUs in France and Belgium over 3 months in 2015. Adult patients with a predicted ICU length of stay > 3 days were consecutively included and followed for 10 days. Their mortality was assessed at D28. We investigated the association between early nutrition (< 48 h) and mortality at D28 using univariate and multivariate propensity-score-weighted logistic regression analyses.

RESULTS

During the study period, 1206 patients were included. Early nutrition support was administered to 718 patients (59.5%), with 504 patients receiving enteral nutrition and 214 parenteral nutrition. Early nutrition was more frequently prescribed in the presence of multiple organ failure and less frequently in overweight and obese patients. Early nutrition was significantly associated with D28 mortality in the univariate analysis (crude odds ratio (OR) 1.69, 95% confidence interval (CI) 1.23-2.34) and propensity-weighted multivariate analysis (adjusted OR (aOR) 1.05, 95% CI 1.00-1.10). In subgroup analyses, this association was stronger in patients ≤ 65 years and with SOFA scores ≤ 8. Compared with no early nutrition, a significant association was found of D28 mortality with early enteral (aOR 1.06, 95% CI 1.01-1.11) but not early parenteral nutrition (aOR 1.04, 95% CI 0.98-1.11).

CONCLUSIONS

In this prospective cohort study, early nutrition support in the ICU was significantly associated with increased mortality at D28, particularly in younger patients with less severe disease. Compared to no early nutrition, only early enteral nutrition appeared to be associated with increased mortality. Such findings are in contrast with current guidelines on the provision of early nutrition support in the ICU and may challenge our current practices, particularly concerning patients at low nutrition risk. Trial registration ClinicalTrials.gov Identifier: NCT02599948. Retrospectively registered on November 5th 2015.

Clinical nutrition issues in 2022: What is missing to trust supplemental parenteral nutrition (SPN) in ICU patients?

A multidisciplinary group of international physicians involved in the medical nutrition therapy (MNT) of adult critically ill patients met to discuss the value, role, and open questions regarding supplemental parenteral nutrition (SPN) along with oral or enteral nutrition (EN), particularly in the intensive care unit (ICU) setting. This manuscript summarizes the discussions and results to highlight the importance of SPN as part of a comprehensive approach to MNT in critically ill adults and for researchers to generate new evidence based on well-powered randomized controlled trials (RCTs). The experts agreed on several key points: SPN has shown clinical benefits, resulting in this strategy being included in American and European guidelines. Nevertheless, its use is heterogeneous across European countries, due to the persistence of uncertainties, such as the optimal timing and the risk of overfeeding in absence of indirect calorimetry (IC), which results in divergent opinions and barriers to SPN implementation. Education is also insufficient. The experts agreed on actions needed to increase evidence quality on SPN use in specific patients at a given time point during acute critical illness or recovery.

[Assessment and technical monitoring of nutritional status of patients in intensive and intermediate care units : Position paper of the Section Metabolism and Nutrition of the German Interdisciplinary Association for Intensive and Emergency Medicine (DIVI)]

At the time of admission to an intensive or intermediate care unit, assessment of the patients' nutritional status may have both prognostic and therapeutic relevance with regard to the planning of individualized medical nutrition therapy (MNT). MNT has definitely no priority in the initial treatment of a critically ill patient, but is often also neglected during the course of the disease. Especially with prolonged length of stay, there is an increasing risk of malnutrition with considerable prognostic macro- and/or micronutrient deficit. So far, there are no structured, evidence-based recommendations for assessing nutritional status in intensive or intermediate care patients. This position paper of the Section Metabolism and Nutrition of the German Interdisciplinary Association for Intensive and Emergency Medicine (DIVI) presents consensus-based recommendations for the assessment and technical monitoring of nutritional status of patients in intensive and intermediate care units. These recommendations supplement the current S2k guideline "Clinical Nutrition in Intensive Care Medicine" of the German Society for Nutritional Medicine (DGEM) and the DIVI.

Performance of NUTRIC score to predict 28-day mortality in critically ill patients after replacing APACHE II with SAPS 3

Objectives

The Nutrition Risk in the Critically Ill (NUTRIC) score has been advocated as a screening tool for nutrition risk assessment in critically ill patients. It was developed and validated to predict 28-day mortality using Acute Physiology and Chronic Health Evaluation II (APACHE II) score as one of its components. However, nowadays the Simplified Acute Physiology Score 3 (SAPS 3) demonstrates better performance. We aimed to test the performance of NUTRIC score in predicting 28-day mortality after replacement of APACHE II by SAPS 3, and the interaction between nutrition adequacy and mortality.

Methods

Adult patients who received nutrition therapy and remained >3 days in intensive care unit were retrospectively evaluated. In order to replace APACHE II component, we used ranges of SAPS 3 with similar predicted mortality. Discrimination between these tools in predicting 28-day mortality was assessed using the ROC curve, calibration was evaluated with calibration belt, and correlation with intraclass correlation. The relationship between nutritional adequacy and mortality was assessed in a subgroup with available data.

Results

542 patients were analyzed (median age of 78 years old, 73.4% admitted for non-surgical reasons and 28-day mortality was 18.1%). Mortality prediction discrimination did not differ between tools (p>0.05), but showed a good agreement (intraclass correlation 0.86) with good calibration. In the subgroup analysis for nutritional adequacy (n = 99), no association with mortality was observed.

Conclusion

Performance of NUTRIC score with SAPS 3 is similar to the original tool. Therefore, it might be used in settings where APACHE II is not available.

Bioenergetic Balance of Continuous Venovenous Hemofiltration, a Retrospective Analysis

(1) Background: Nutrition therapy guided by indirect calorimetry (IC) is the gold standard and is associated with lower morbidity and mortality in critically ill patients. When performing IC during continuous venovenous hemofiltration (CVVH), the measured VCO₂ should be corrected for the exchanged CO₂ to calculate the ‘true’ Resting Energy Expenditure (REE). After the determination of the true REE, the caloric prescription should be adapted to the removal and addition of non-intentional calories due to citrate, glucose, and lactate in dialysis fluids to avoid over- and underfeeding. We aimed to evaluate this bioenergetic balance during CVVH and how nutrition therapy should be adapted. (2) Methods: This post hoc analysis evaluated citrate, glucose, and lactate exchange. Bioenergetic balances were calculated based on these values during three different CVVH settings: low dose with citrate, high dose with citrate, and low dose without citrate. The caloric load of these non-intentional calories during a CVVH-run was compared to the true REE. (3) Results: We included 19 CVVH-runs. The bioenergetic balance during the low dose with citrate was 498 ± 110 kcal/day (range 339 to 681 kcal/day) or 26 ± 9% (range 14 to 42%) of the true REE. During the high dose with citrate, it was 262 ± 222 kcal/day (range 56 to 262 kcal/day) or 17 ± 11% (range 7 to 32%) of the true REE. During the low dose without citrate, the bioenergetic balance was −189 ± 77 kcal/day (range −298 to −92 kcal/day) or −13 ± 8% (range −28 to −5%) of the true REE. (4) Conclusions: Different CVVH settings resulted in different bioenergetic balances ranging from −28% up to +42% of the true REE depending on the CVVH fluids chosen. When formulating a caloric prescription during CVVH, an individual approach considering the impact of these non-intentional calories is warranted.

Reply to Martindale, et al.: Clarity, Scientific Rigor, and A Call to Action

We thank the authors for their interest in our updates to the critical care nutrition guidelines and appreciate their thoughtful and germane comments. We would like to address each of their concerns, in a point by point manner, with the intention of providing clarity on the 2022 guidelines update. This article is protected by copyright. All rights reserved.

Protocol summary and statistical analysis plan for ntensive utrition herapy compard to usual care i criically ill adults (INTENT): a phase II randomised controlled trial

INTRODUCTION

It is plausible that a longer duration of nutrition intervention may have a greater impact on clinical and patient-centred outcomes. The Intensive Nutrition care Therapy comparEd to usual care iN criTically ill adults (INTENT) trial will determine if a whole hospital nutrition intervention is feasible and will deliver more total energy compared with usual care in critically ill patients with at least one organ system failure.

METHODS AND ANALYSIS

This study is a prospective, multicentre, unblinded, parallel-group, phase II randomised controlled trial (RCT) conducted in 23 hospitals in Australia and New Zealand. Mechanically ventilated critically ill adult patients with at least one organ failure who have been in intensive care unit (ICU) for 72-120 hours and meet all of the inclusion and none of the exclusion criteria will be randomised to receive either intensive or usual nutrition care. INTENT started recruitment in October 2018 and a sample size of 240 participants is anticipated to be recruited in 2022. The study period is from randomisation to hospital discharge or study day 28, whichever occurs first, and the primary outcome is daily energy delivery from nutrition therapy. Secondary outcomes include daily energy and protein delivery during ICU and in the post-ICU period, duration of ventilation, ventilator-free days, total bloodstream infection rate and length of hospital stay. All other outcomes are considered tertiary and results will be analysed on an intention-to-treat basis.

ETHICS AND DISSEMINATION

Ethics approval has been received in Australia (Alfred Hospital Ethics Committee (HREC/18/Alfred/101) and Human Research Ethics Committee of the Northern Territory Department of Health (2019-3372)) and New Zealand (Northern A Health and Disability Ethics Committee (18/NTA/222). Results will be disseminated in an international peer-reviewed journal(s), at scientific meetings and via social media.

TRIAL REGISTRATION NUMBER

NCT03292237.

Nutrition priorities in obese critically ill patients

PURPOSE OF REVIEW

During critical illness, several neuroendocrine, inflammatory, immune, adipokine, and gastrointestinal tract hormone pathways are activated; some of which are more intensified among obese compared with nonobese patients. Nutrition support may mitigate some of these effects. Nutrition priorities in obese critically ill patients include screening for nutritional risk, estimation of energy and protein requirement, and provision of macronutrients and micronutrients.

RECENT FINDINGS

Estimation of energy requirement in obese critically ill patients is challenging because of variations in body composition among obese patients and absence of reliable predictive equations for energy expenditure. Whereas hypocaloric nutrition with high protein has been advocated in obese critically ill patients, supporting data are scarce. Recent studies did not show differences in outcomes between hypocaloric and eucaloric nutrition, except for better glycemic control. Sarcopenia is common among obese patients, and the provision of increased protein intake has been suggested to mitigate catabolic changes especially after the acute phase of critical illness. However, high-quality data on high protein intake in these patients are lacking. Micronutrient deficiencies among obese critically ill patients are common but the role of their routine supplementation requires further study.

SUMMARY

An individualized approach for nutritional support may be needed for obese critically ill patients but high-quality evidence is lacking. Future studies should focus on nutrition priorities in this population, with efficient and adequately powered studies.

How much underfeeding can the critically ill adult patient tolerate?

Critical illness leads to significant metabolic alterations that should be considered when providing nutritional support. Findings from key randomized controlled trials (RCTs) indicate that underfeeding (<70% of energy expenditure [EE]) during the acute phase of critical illness (first 7 days of intensive care unit [ICU] admission) may not be harmful and could instead promote autophagy and prevent overfeeding in light of endogenous energy production. However, the optimal energy target during this period is unclear and full starvation is unlikely to be beneficial. There are limited data regarding the effects of prolonged underfeeding on clinical outcomes in critically ill patients, but recent studies show that oral food intake is suboptimal both in the ICU and following discharge to the acute care setting. It is hypothesized that provision of full nutrition (70-100% of EE) may be important in the recovery phase of critical illness (>7 days of ICU admission) for promoting recovery and rehabilitation; however, studies on nutritional intervention delivered from ICU admission through hospital discharge are needed. The aim of this review is to provide a narrative synthesis of the existing literature on metabolic alterations experienced during critical illness and the impact of underfeeding on clinical outcomes in the critically ill adult patient.

U-Shape Relationship between Plasma Leucine Level and Mortality in the Intensive Care Unit

Patients in the intensive care unit (ICU) are at high risk of mortality which is not well predicted. Previous studies noted that leucine has prognostic value in a variety of diseases. This study investigated whether leucine concentration was a useful biomarker of metabolic and nutritional status and 6-month mortality in ICU. We recruited 454 subjects admitted to ICU (348 and 106 in the initiation and validation cohorts, respectively) with an acute physiology and chronic health evaluation (APACHE II) score ≥ 15. We measured plasma leucine concentrations, traditional biomarkers, and calculated APACHE II and sequential organ failure assessment (SOFA) scores. Leucine levels were weakly correlated with albumin, prealbumin, and transferrin levels (r = 0.30, 0.12, and 0.15, p = 0.001, 0.029, and 0.007, respectively). During follow-up, 116 (33.3%) patients died. Compared to patients with leucine levels between 109 and 174 μM, patients with leucine > 174 μM or <109 μM had a lower cumulative survival rate. Death was also associated with age, higher APACHE II and SOFA scores, C-reactive protein, and longer stays in the ICU, but with lower albumin, prealbumin, and transferrin. Patients with leucine levels > 174 μM had higher alanine aminotransferase levels, but no significant differences in other variables; patients with leucine levels < 109 μM had higher APACHE II and SOFA scores, higher incidence of using inotropic agents, longer ICU and hospital stays, but lower albumin and transferrin levels. Multivariable analysis demonstrated that leucine > 174 μM was an independent predictor of mortality, especially early mortality. However, among patients who stayed in ICU longer than two weeks, leucine < 109 μM was an independent predictor of mortality. In addition, leucine < 109 μM was associated with worse ventilator weaning profiles. These findings were similar in the validation cohort. Our study demonstrated a U-shape relationship between leucine levels and mortality rate in ICU.

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.

Nutrition support for critically ill patients

Nutrition support is an important aspect of the management of critically ill patients. This review highlights the emerging evidence on critical care nutrition and focuses on the pathophysiologic interplay between critical illness, the gastrointestinal tract, and nutrition support and the evidence on the best route, dose, and timing of nutrition. Although indirect calorimetry is recommended to measure energy expenditure, predictive equations are commonly used but are limited by their inaccuracy in individual patients. The current evidence supports early enteral nutrition (EN) in most patients, with a gradual increase in the daily dose over the first week. Delayed EN is warranted in patients with severe shock. According to recent trials, parenteral nutrition seems to be as effective as EN and may be started if adequate EN is not achieved by the first week of critical illness. A high protein dose has been recommended, but the best timing is unclear. Immuno-nutrition should not be routinely provided to critically ill patients. Patients receiving artificial nutrition should be monitored for metabolic derangements. Additional adequately powered studies are still needed to resolve many unanswered questions.

Use of modified-NUTRIC score to assess nutritional risk in surgical intensive care unit

BACKGROUND

Modified Nutrition Risk in the Critically Ill (m-NUTRIC) score is used to evaluate the nutritional risk of patients in intensive care units (ICUs). This study aimed to investigate whether m-NUTRIC can be used as a predictive factor related to the outcome of patients in surgical ICU (SICU) and to identify which patients will benefit from aggressive nutritional intervention according to the results of m-NUTRIC score.

METHODS

A total of 205 patients who were admitted to surgical ICU (SICU) with ventilator use for more than 24 hours were enrolled. The m-NUTRIC score data were calculated the day when the patients were admitted to SICU. Patients were divided into two groups according to their m-NUTRIC score: the low-risk group (<5 points, 116 patients) and the high risk group (≥5 points, 89 patients).

RESULTS

In this study, a total of 205 patients were enrolled for analysis, including patients in the low-risk group (n = 116) and those in the high risk group (n = 89). The mean duration of ventilator use was 3.6 ± 6.5 days, and average SICU stays for all patients was 5.1 ± 7.4 days. The SICU mortality was significantly higher in the high-risk group (10.3% vs 1.7%). Comparison between survivals and nonsurvivals was carried out, and the data showed that the AKI, Vasopressors, SOFA, APACHE-II, m-NUTRIC score, and shock patient were all significantly associated with higher mortality. The multivariate analysis revealed that acute kidney injury (OR = 13.16; 95% confidence intervals = 3.69-46.92; p < 0.0001) and m-NUTRIC score were independent factors of ICU mortality in these patients. A receiver operating characteristic curve was used to calculate the area under the curve, which was 0.801. The data indicated that high m-NUTRIC score were significantly associated with SICU mortality with the cutoff score > 4 (sensitivity = 90.5%, specificity = 62.3%, p < 0.001).

CONCLUSION

We found in this study that the high m-NUTRIC score is an independent factor of ICU mortality, and m-NUTRIC score can be used as an initial screening tool for nutritional assessment in patients admitted to surgical ICU. Further investigations to evaluate whether the aggressive nutritional intervention would be beneficial in the SICU patients with higher m-NUTRIC score is mandatory.

Nutrition in the Intensive Care Unit-A Narrative Review

Background: While consent exists, that nutritional status has prognostic impact in the critically ill, the optimal feeding strategy has been a matter of debate. Methods: Narrative review of the recent evidence and international guideline recommendations focusing on basic principles of nutrition in the ICU and the treatment of specific patient groups. Covered topics are: the importance and diagnosis of malnutrition in the ICU, the optimal timing and route of nutrition, energy and protein requirements, the supplementation of specific nutrients, as well as monitoring and complications of a Medical Nutrition Therapy (MNT). Furthermore, this review summarizes the available evidence to optimize the MNT of patients grouped by primarily affected organ system. Results: Due to the considerable heterogeneity of the critically ill, MNT should be carefully adapted to the individual patient with special focus on phase of critical illness, metabolic tolerance, leading symptoms, and comorbidities. Conclusion: MNT in the ICU is complex and requiring an interdisciplinary approach and frequent reevaluation. The impact of personalized and disease-specific MNT on patient-centered clinical outcomes remains to be elucidated.

Initial development and validation of a novel nutrition risk, sarcopenia, and frailty assessment tool in mechanically ventilated critically ill patients: The NUTRIC-SF score

BACKGROUND

Nutrition risk, sarcopenia, and frailty are interrelated. They may be due to suboptimal or prevented by optimal nutrition intake. The combination of nutrition risk (modified nutrition risk in the critically ill [mNUTRIC]), sarcopenia (SARC-F combined with calf circumference [SARC-CALF]), and frailty (clinical frailty scale [CFS]) in a single score may better predict adverse outcomes and prioritize resources for optimal nutrition in the intensive care unit (ICU) METHODS: This is a retrospective analysis of a single-center prospective observational study that enrolled mechanically ventilated adults with expected ≥96 h of ICU stay. SARC-F and CFS questionnaires were administered to patient's next-of-kin and mNUTRIC were calculated. Right calf circumference was measured. Nutrition data were collected from nursing record. The high-risk scores (mNUTRIC ≥ 5, SARC-CALF > 10, or CFS ≥ 4) of these variables were combined to become the nutrition risk, sarcopenia, and frailty (NUTRIC-SF) score (range: 0-3).

RESULTS

Eighty-eight patients were analyzed. Increasing mNUTRIC was independently associated with 60-day mortality, whereas increasing SARC-CALF and CFS showed a strong trend towards a higher 60-day mortality. Discriminative ability of NUTRIC-SF for 60-day mortality is better than its component (C-statistics, 0.722; 95% confidence interval [CI], 0.677-0.868). Every increment of 300 kcal/day and 30 g/day is associated with a trend towards higher rate of discharge alive for high (≥2; adjusted hazard ratio, 1.453 [95% CI, 0.991-2.130] for energy; 1.503 [0.936-2.413] for protein) but not low (<2) NUTRIC-SF score.

CONCLUSION

NUTRIC-SF may be a clinically relevant risk stratification tool in the ICU.

Validation of the modified NUTrition Risk Score (mNUTRIC) in mechanically ventilated, severe burn patients: A prospective multinational cohort study

BACKGROUND

Whether nutrition therapy benefits all burn victims equally is unknown. To identify patients who will benefit the most from optimal nutrition, the modified Nutrition Risk in Critically Ill (mNUTRIC) Score has been validated in the Intensive Care Unit. However, the utility of mNUTRIC in severe burn victims is unknown. We hypothesized that a higher mNUTRIC (≥5) will be associated with worse clinical outcomes, but that greater nutritional adequacy will be associated with better clinical outcomes in patients with higher mNUTRIC score.

METHODS

This prospective study included data from mechanically ventilated, severe burn patients (n = 359) from 51 Burn Units worldwide included in a randomized trial. Our primary and secondary outcomes were hospital mortality and the time to discharge alive (TTDA) from hospital. We described the association between nutrition performance and clinical outcomes.

RESULTS

Compared to low mNUTRIC (n = 313), the high mNUTRIC group (n = 46) had higher mortality (61% vs. 19%, p = 0.001), and longer TTDA (>90 [87->90] vs. 64 [38-90] days, p = <0.0001). Only in the high mNUTRIC group, increased calorie intake (per 20% increase) was associated with lower mortality and a faster TTDA.

CONCLUSIONS

The mNUTRIC score identifies those with poor clinical outcomes and may identifies those mechanically ventilated, severe burn patients in whom optimal nutrition therapy may be more advantageous.

Energy expenditure and delivery: does the Micawber principle apply during critical illness?

PURPOSE OF REVIEW

To determine from existing literature if achieving energy balance in critically ill patients improves outcome. Only randomized clinical trials were considered. Furthermore, the intent had to be that energy intake of the treatment group would reach 100% of requirement, and that the requirement was measured and not estimated.

RECENT FINDINGS

Six studies meeting the above criteria were identified. Truly positive energy balance was rarely achieved in these studies and protein intake was a confounder because it often varied with the energy intake. The two studies in which energy balance came closest to 100% did suggest clinical benefit, but in both of these studies protein intake was also higher in the high-energy intake group.

SUMMARY

The question posed cannot be fully answered based on the available literature. There are some signals that the pursuit of energy balance in critically ill patients might be favorable, but significant uncertainty remains.

Reduced exposure to vasopressors through permissive hypotension to reduce mortality in critically ill people aged 65 and over: the 65 RCT

BACKGROUND

Vasopressors are administered to critical care patients to avoid hypotension, which is associated with myocardial injury, kidney injury and death. However, they work by causing vasoconstriction, which may reduce blood flow and cause other adverse effects. A mean arterial pressure target typically guides administration. An individual patient data meta-analysis (Lamontagne F, Day AG, Meade MO, Cook DJ, Guyatt GH, Hylands M, et al. Pooled analysis of higher versus lower blood pressure targets for vasopressor therapy septic and vasodilatory shock. Intensive Care Med 2018;44:12-21) suggested that greater exposure, through higher mean arterial pressure targets, may increase risk of death in older patients.

OBJECTIVE

To estimate the clinical effectiveness and cost-effectiveness of reduced vasopressor exposure through permissive hypotension (i.e. a lower mean arterial pressure target of 60-65 mmHg) in older critically ill patients.

DESIGN

A pragmatic, randomised clinical trial with integrated economic evaluation.

SETTING

Sixty-five NHS adult general critical care units.

PARTICIPANTS

Critically ill patients aged ≥ 65 years receiving vasopressors for vasodilatory hypotension.

INTERVENTIONS

Intervention - permissive hypotension (i.e. a mean arterial pressure target of 60-65 mmHg). Control (usual care) - a mean arterial pressure target at the treating clinician's discretion.

MAIN OUTCOME MEASURES

The primary clinical outcome was 90-day all-cause mortality. The primary cost-effectiveness outcome was 90-day incremental net monetary benefit. Secondary outcomes included receipt and duration of advanced respiratory and renal support, mortality at critical care and acute hospital discharge, and questionnaire assessment of cognitive decline and health-related quality of life at 90 days and 1 year.

RESULTS

Of 2600 patients randomised, 2463 (permissive hypotension, n = 1221; usual care, n = 1242) were analysed for the primary clinical outcome. Permissive hypotension resulted in lower exposure to vasopressors than usual care [mean duration 46.0 vs. 55.9 hours, difference -9.9 hours (95% confidence interval -14.3 to -5.5 hours); total noradrenaline-equivalent dose 31.5 mg vs. 44.3 mg, difference -12.8 mg (95% CI -18.0 mg to -17.6 mg)]. By 90 days, 500 (41.0%) patients in the permissive hypotension group and 544 (43.8%) patients in the usual-care group had died (absolute risk difference -2.85%, 95% confidence interval -6.75% to 1.05%; p = 0.154). Adjustment for prespecified baseline variables resulted in an odds ratio for 90-day mortality of 0.82 (95% confidence interval 0.68 to 0.98) favouring permissive hypotension. There were no significant differences in prespecified secondary outcomes or subgroups; however, patients with chronic hypertension showed a mortality difference favourable to permissive hypotension. At 90 days, permissive hypotension showed similar costs to usual care. However, with higher incremental life-years and quality-adjusted life-years in the permissive hypotension group, the incremental net monetary benefit was positive, but with high statistical uncertainty (£378, 95% confidence interval -£1347 to £2103).

LIMITATIONS

The intervention was unblinded, with risk of bias minimised through central allocation concealment and a primary outcome not subject to observer bias. The control group event rate was higher than anticipated.

CONCLUSIONS

In critically ill patients aged ≥ 65 years receiving vasopressors for vasodilatory hypotension, permissive hypotension did not significantly reduce 90-day mortality compared with usual care. The absolute treatment effect on 90-day mortality, based on 95% confidence intervals, was between a 6.8-percentage reduction and a 1.1-percentage increase in mortality.

FUTURE WORK

Future work should (1) update the individual patient data meta-analysis, (2) explore approaches for evaluating heterogeneity of treatment effect and (3) explore 65 trial conduct, including use of deferred consent, to inform future trials.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN10580502.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 14. See the NIHR Journals Library website for further project information.

Nutritional Support and Clinical Outcome of Severe and Critical Patients With COVID-19 Pneumonia

Background: In 2020, a novel coronavirus has spread throughout the world. More than four hundred thousand people have died of SARS-CoV-2 pneumonia, most of which were severe and critical patients. No effective antiviral treatment has been verified thus far. Nutrition support has become one of the important treatments for severe and critical patients.

Methods: In this retrospective study, 26 severe patients and 22 critical patients with laboratory confirmed COVID-19 were enrolled. We recorded the diet and nutritional treatments in severe and critical patients. Baseline characteristics and clinical outcomes of severe and critical patients were also collected.

Results: Average calorie intake of severe patients (19.3 kcal/kg/d) was higher than critical patients (15.3 kcal/kg/d) (P = 0.04). Protein intake was similar in the two groups (0.65 and 0.62 g/kg per day, respectively; P = 0.29). There was no significant difference in the median duration of viral shedding between the severe and critical patients (P = 0.354).

Conclusions: A permissive underfeeding strategy that restricts non-protein calories but preserves protein intake is feasible for critical patients with SARS-CoV-2 pneumonia. Viral shedding duration of critical patients was the same as severe patients who received standard feeding. Nevertheless, evidence of the conclusion is not sufficient because of small sample size. To show the real clinical benefit of permissive low-calorie and adequate protein intake in critical SARS-CoV-2 pneumonia patients, a large and pragmatic randomized controlled trial is needed.

Ward-based nutrition care practices and a snapshot of patient care: Results from nutritionDay in the ICU

BACKGROUND

Poor adherence to intensive care unit (ICU) guidelines is common, leading to suboptimal nutritional care. This study determined current ward-based nutrition care practices in the Indian ICU setting, comparing them to international best-practice guidelines and provided patient demographic, clinical and nutritional information to serve as baseline data for future benchmarking.

METHODS

This multi-site cross-sectional retrospective study analysed data collected from nutritionDay worldwide audits (2012-2016) across ICUs from a chain of urban private hospitals in India. Additional guideline-specific data were collected through questionnaires and phone interviews with the Head of Dietetics Departments in the participating hospitals.

RESULTS

Overall, 10 ICUs and 457 participants were included. It was common practice to use modified versions of the Mini Nutritional Assessment-Short Form (MNA-SF) and Subjective Global Assessment (SGA) for nutrition screening and assessment. Nearly half the participants (n = 222, 49%) received nutrition orally. A majority of the remaining participants received enteral nutrition (n = 163, 36%) or no nutrition (n = 60, 13%) at the time of data collection. The calories prescribed for most participants were between 1500 and 1999 kilocalories per day (n = 207, 45%), with no nutrition planned for 115 (25%) participants. Three-quarters (n = 129, 74%) of participants on EN received the planned calories, while 24% (n = 42) were given less than planned.

CONCLUSION

Overall, most participants received the calories planned for enteral nutrition. The use of modified screening and assessment tools and suboptimal delivery of EN remains a global problem for critical care, possibly requiring a more pragmatic approach to nutritional therapy.

Full Versus Trophic Feeds in Critically Ill Adults with High and Low Nutritional Risk Scores: A Randomized Controlled Trial

Although energy intake might be associated with clinical outcomes in critically ill patients, it remains unclear whether full or trophic feeding is suitable for critically ill patients with high or low nutrition risk. We conducted a prospective study to determine which feeding energy intakes were associated with clinical outcomes in critically ill patients with high or low nutrition risk. This was an investigator-initiated, single center, single blind, randomized controlled trial. Critically ill patients were allocated to either high or low nutrition risk based on their Nutrition Risk in the Critically Ill score, and then randomized to receive either the full or the trophic feeding. The feeding procedure was administered for six days. No significant differences were observed in hospital, 14-day and 28-day mortalities, the length of ventilator dependency, or ICU and hospital stay among the four groups. There were no associations between energy and protein intakes and hospital, 14-day and 28-day mortalities in any of the four groups. However, protein intake was positively associated with the length of hospital stay and ventilator dependency in patients with low nutrition risk receiving trophic feeding. Full or trophic feeding in critically ill patients showed no associations with clinical outcomes, regardless of nutrition risk.

Optimal VAsopressor TitraTION in patients 65 years and older (OVATION-65): protocol and statistical analysis plan for a randomised clinical trial

INTRODUCTION

Vasodilatory hypotension is common among intensive care unit (ICU) patients; vasopressors are considered standard of care. However, optimal mean arterial pressure (MAP) targets for vasopressor titration are unknown. The objective of the Optimal VAsopressor TitraTION in patients 65 years and older (OVATION-65) trial is to ascertain the effect of permissive hypotension (vasopressor titration to achieve MAP 60-65 mm Hg) versus usual care on biomarkers of organ injury in hypotensive patients aged ≥65 years.

METHODS AND ANALYSIS

OVATION-65 is an allocation-concealed randomised trial in 7 Canadian hospitals. Eligible patients are ≥65 years of age, in an ICU with vasodilatory hypotension, receiving vasopressors for ≤12 hours to maintain MAP ≥65 mm Hg during or after adequate fluid resuscitation, and expected to receive vasopressors for ≥6 additional hours. Patients are excluded for any of the following: active treatment for spinal cord or acute brain injury; vasopressors given solely for bleeding, ventricular failure or postcardiopulmonary bypass vasoplegia; withdrawal of life-sustaining treatments expected within 48 hours; death perceived as imminent; previous enrolment in OVATION-65; organ transplant within the last year; receiving extracorporeal life support or lack of physician equipoise. Patients are randomised to permissive hypotension versus usual care for up to 28 days. The primary outcome is high-sensitivity troponin T, a biomarker of cardiac injury, on day 3. Secondary outcomes include biomarkers of injury to other organs (brain, liver, intestine, skeletal muscle); lactate (a biomarker of global tissue dysoxia); resource utilisation; adverse events; mortality (90 days and 6 months) and cognitive function (6 months). Assessors of biomarkers, mortality and cognitive function are blinded to allocation.

ETHICS AND DISSEMINATION

This protocol has been approved at all sites. Consent is obtained from the eligible patient, the substitute decision-maker if the patient is incapable, or in a deferred fashion where permitted. End-of-grant dissemination plans include presentations, publications and social media platforms and discussion forums.

TRIAL REGISTRATION NUMBER

NCT03431181.

Nutritional Assessment: A Primary Component of the Multidimensional Geriatric Assessment in the Intensive Care Unit

The importance of evaluating and adjusting the nutritional state of critically ill patients has become a core principle of care. This article focuses on tools for the nutritional assessment of geriatric intensive care unit patients, including a review of imaging and other standardized techniques for evaluation of muscle mass, an indicator of malnutrition and sarcopenia. It concludes with a discussion of the interplay of malnutrition, reduced muscle mass/sarcopenia, and frailty. The goal of this multidimensional assessment is to identify those at risk and thereby initiate interventions to improve outcomes.

Value of the urea/creatinine index in isolated urine to estimate severe protein hypercatabolism in ventilated patients

Objective

To study the ability of the urea/creatinine index to identify severe protein catabolism from the isolated urine of critically ventilated patients.

Methods

This was a prospective, observational study. It included 52 patients without kidney failure. Variables: total urinary nitrogen estimated from the urea in 24-hour urine on the second (T1) and fourth days (T2) and urea/creatinine index in isolated urine before 24-hour urine collection.

Results

Severe protein hypercatabolism (estimated total urinary nitrogen > 15g) was present in 14 patients (26.9%) at T1 and in 29 (55.7%) at T2. Eighty-four percent of patients had low nutritional risk by the Nutrition Risk in the Critically Ill score. At T1, the Pearson correlation between the estimated total urinary nitrogen and the urea/creatinine index was 0.272 (p = 0.051), and at T2 it was 0.276 (p = 0.048). The urea/creatinine index at T2 had a tendency to better discriminate severe protein hypercatabolism than Acute Physiology and Chronic Health Evaluation II and Nutrition Risk in the Critically Ill (AUC 0.741 versus 0.669 and 0.656, 95%CI: 0.602 - 0.880; 0.519 - 0.818 and 0.506 - 0.806, respectively). The optimal cutoff value of the urea/creatinine index for the diagnosis of severe protein hypercatabolism was 16.15, with a sensitivity of 79.31% (95%CI: 59.74 - 91.29), specificity of 60.87% (95%CI: 38.78 - 79.53), positive predictive value 71.88% (95%CI: 53.02 - 85.60), negative predictive value 70.0% (95%CI: 45.67 - 87.18), LR (+) 2.03 (95%CI: 1.18 - 3.49), and LR (-) 0.34 (95%CI: 0.16 - 0.74).

Conclusion

The urea/creatinine index measured on the fourth day has a certain ability to estimate severe protein hypercatabolism (as defined by estimated total urinary nitrogen) but does not replace total urinary nitrogen in critically ventilated patients without kidney failure. Due to its reasonable sensitivity, it could be used as a screen to identify which patients to take a 24-hour urine sample from.

First international meeting of early career investigators: Current opportunities, challenges and horizon in critical care nutrition research

BACKGROUND

Appropriate nutritional support is a key component of care for critically ill patients. While malnutrition increases complications, impacting long term outcomes and healthcare-related costs, uncertainties persist regarding optimal provision of nutritional support in this setting.

METHODS

An international group of healthcare providers (HCPs) from critical care specialties and nutrition researchers convened to identify knowledge gaps and learnings from studies in critical care nutrition. Clinical research needs were identified in order to better inform future nutrition practices.

RESULTS

Challenges in critical care nutrition arise, in part, from inconsistent outcomes in several large-scale studies regarding the optimal amount of calories and protein to prescribe, the optimal time to initiate nutritional support and the role of parental nutrition to support critically ill patients. Furthermore, there is uncertainty on how best to identify patients at nutritional risk, and the appropriate outcome measures for ICU nutrition studies. Given HCPs have a suboptimal evidence base to inform the nutritional management of critically ill patients, further well-designed clinical trials capturing clinically relevant endpoints are needed to address these knowledge gaps.

CONCLUSIONS

The identified aspects for future research could be addressed in studies designed and conducted in collaboration with an international team of interdisciplinary nutrition experts. The aim of this collaboration is to address the unmet need for robust clinical data needed to develop high-quality evidence-based nutritional intervention recommendations to better inform the future management of critically ill patients.

Human adaptation to hypoxia in critical illness

The syndrome of critical illness is a complex physiological stressor that can be triggered by diverse pathologies. It is widely believed that organ dysfunction and death result from bioenergetic failure caused by inadequate cellular oxygen supply. Teleologically, life has evolved to survive in the face of stressors by undergoing a suite of adaptive changes. Adaptation not only comprises alterations in systemic physiology but also involves molecular reprogramming within cells. The concept of cellular adaptation in critically ill patients is a matter of contention in part because medical interventions mask underlying physiology, creating the artificial construct of "chronic critical illness," without which death would be imminent. Thus far, the intensive care armamentarium has not targeted cellular metabolism to preserve a temporary equilibrium but instead attempts to normalize global oxygen and substrate delivery. Here, we review adaptations to hypoxia that have been demonstrated in cellular models and in human conditions associated with hypoxia, including the hypobaric hypoxia of high altitude, the intrauterine low-oxygen environment, and adult myocardial hibernation. Common features include upregulation of glycolytic ATP production, enhancement of respiratory efficiency, downregulation of mitochondrial density, and suppression of energy-consuming processes. We argue that these innate cellular adaptations to hypoxia represent potential avenues for intervention that have thus far remained untapped by intensive care medicine.

Biomarkers in critical care nutrition

The goal of nutrition support is to provide the substrates required to match the bioenergetic needs of the patient and promote the net synthesis of macromolecules required for the preservation of lean mass, organ function, and immunity. Contemporary observational studies have exposed the pervasive undernutrition of critically ill patients and its association with adverse clinical outcomes. The intuitive hypothesis is that optimization of nutrition delivery should improve ICU clinical outcomes. It is therefore surprising that multiple large randomized controlled trials have failed to demonstrate the clinical benefit of restoring or maximizing nutrient intake. This may be in part due to the absence of biological markers that identify patients who are most likely to benefit from nutrition interventions and that monitor the effects of nutrition support. Here, we discuss the need for practical risk stratification tools in critical care nutrition, a proposed rationale for targeted biomarker development, and potential approaches that can be adopted for biomarker identification and validation in the field.

Quantifying Response to Nutrition Therapy During Critical Illness: Implications for Clinical Practice and Research? A Narrative Review

Critical illness causes substantial muscle loss that adversely impacts recovery and health-related quality of life. Treatments are therefore needed that reduce mortality and/or improve the quality of survivorship. The purpose of this Review is to describe both patient-centered and surrogate outcomes that quantify responses to nutrition therapy in critically ill patients. The use of these outcomes in randomized clinical trials will be described and the strengths and limitations of these outcomes detailed. Outcomes used to quantify the response of nutrition therapy must have a plausible mechanistic relationship to nutrition therapy and either be an accepted measure for the quality of survivorship or highly likely to lead to improvements in survivorship. This Review identified that previous trials have utilized diverse outcomes. The variety of outcomes observed is probably due to a lack of consensus as to the most appropriate surrogate outcomes to quantify response to nutrition therapy during research or clinical practice. Recent studies have used, with some success, measures of muscle mass to evaluate and monitor nutrition interventions administered to critically ill patients.

Meeting nutritional targets of critically ill patients by combined enteral and parenteral nutrition: review and rationale for the EFFORTcombo trial

While medical nutrition therapy is an essential part of the care for critically ill patients, uncertainty exists about the right form, dosage, timing and route in relation to the phases of critical illness. As enteral nutrition (EN) is often withheld or interrupted during the intensive care unit (ICU) stay, combined EN and parenteral nutrition (PN) may represent an effective and safe option to achieve energy and protein goals as recommended by international guidelines. We hypothesise that critically ill patients at high nutritional risk may benefit from such a combined approach during their stay on the ICU. Therefore, we aim to test if an early combination of EN and high-protein PN (EN+PN) is effective in reaching energy and protein goals in patients at high nutritional risk, while avoiding overfeeding. This approach will be tested in the here-presented EFFORTcombo trial. Nutritionally high-risk ICU patients will be randomised to either high (≥2·2 g/kg per d) or low protein (≤1·2 g/kg per d). In the high protein group, the patients will receive EN+PN; in the low protein group, patients will be given EN alone. EN will be started in accordance with international guidelines in both groups. Efforts will be made to reach nutrition goals within 48-96 h. The efficacy of the proposed nutritional strategy will be tested as an innovative approach by functional outcomes at ICU and hospital discharge, as well as at a 6-month follow-up.

Comparison of Feeding Efficiency and Hospital Mortality between Small Bowel and Nasogastric Tube Feeding in Critically Ill Patients at High Nutritional Risk

Nasogastric tube enteral nutrition (NGEN) should be initiated within 48 h for patients at high nutritional risk. However, whether small bowel enteral nutrition (SBEN) should be routinely used instead of NGEN to improve hospital mortality remains unclear. We retrospectively analyzed 113 critically ill patients with modified Nutrition Risk in Critically Ill (mNUTRIC) score ≥ 5 and feeding volume < 750 mL/day in the first week of their stay in the intensive care unit (ICU). Age, sex, mNUTRIC score, and Acute Physiology and Chronic Health Evaluation II (APACHE II) score were matched in the SBEN (n = 48) and NGEN (n = 65) groups. Through a univariate analysis, factors associated with hospital mortality were SBEN group (hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.31-1.00), Simplified Organ Failure Assessment (SOFA) score on day 7 (HR, 1.12; 95% CI, 1.03-1.22), and energy intake achievement rate < 65% (HR, 2.53; 95% CI, 1.25-5.11). A multivariate analysis indicated that energy intake achievement rate < 65% on the third follow-up day (HR, 2.29; 95% CI, 1.12-4.69) was the only factor independently associated with mortality. We suggest initiation of SBEN on the seventh ICU day before parenteral nutrition initiation for critically ill patients at high nutrition risk.

Differential Effects of Early Energy and Protein Inadequacies on the Outcome of Critically Ill Patients

BACKGROUND

Differential effects of energy and protein inadequacies of intensive care unit (ICU) patients in first 72 hours are unknown.

METHODS

We included all adult patients receiving mechanical ventilation (MV) > 72 hours between August 2012 and December 2014. Energy and protein doses were 25 kcal/kg/day and 1.5 g/kg/day, respectively. We used multivariable Cox regression analysis for 28-day mortality and competing risks regression analysis for post-ICU length of stay (LOS) in hospital survivors.

RESULTS

In 421 patients (male 63.4%, mean age 62 ± 15.1 years) the energy and protein adequacies at 72 hours were 70% and 56%, respectively. Non-survivors by day 28 were started on feeding significantly later (median, 14.13 (5.48-33.78) versus 9.25 (5.45-16.58) hours, P = .003) and received lower energy (mean, 0.57 ± 0.36 versus 0.76 ± 0.29, P < 0.001) and protein (median, 0.51 (0.13-0.74) versus 0.61 (0.40-0.84), P < 0.001) adequacies at day 7 (same effect seen at 72 hours, P < 0.001). Higher energy adequacy at 72 hours was associated with lower mortality (hazard ratio [HR], 0.39 (95% CI 0.20-0.75), P = 0.004); the lowest mortality was seen between 61% and 70% energy adequacies. No such association was seen with protein adequacy. In 280 hospital survivors, higher energy adequacy at 72 hours (subdistribution HR 1.63; 95% CI, 1.06-2.50, P = 0.025) was significantly associated with shorter post-ICU LOS. No such effect was seen with protein adequacy.

CONCLUSION

Higher energy but not protein adequacy at 72 hours of MV was associated with improved patient-centric outcomes.

Elevated plasma phenylalanine predicts mortality in critical patients with heart failure

Aims

Previous studies found a relationship between elevated phenylalanine levels and poor cardiovascular outcomes. Potential strategies are available to manipulate phenylalanine metabolism. This study investigated whether increased phenylalanine predicted mortality in critical patients with either acute heart failure (HF) or acute on chronic HF, and its correlation with inflammation and immune cytokines.

Methods and results

This study recruited 152 subjects, including 115 patients with HF admitted for critical conditions and 37 normal controls. We measured left ventricular ejection fraction (LVEF), plasma concentrations of phenylalanine, C‐reactive protein, albumin, pre‐albumin, transferrin, and pro‐inflammatory and immune cytokines. Acute Physiology and Chronic Health Evaluation (APACHE II), Sequential Organ Failure Assessment (SOFA), and maximal vasoactive–inotropic scores (VIS_max) were calculated. Patients were followed up until death or a maximum of 1 year. The primary endpoint was all‐cause death. Of the 115 patients, 37 (32.2%) were admitted owing to acute HF, and 78 (67.8%) were admitted owing to acute on chronic HF; 64 (55.7%) had ST elevation/non‐ST elevation myocardial infarction. An LVEF measured during the hospitalization of <40%, 40–50%, and ≥50% was noted in 51 (44.3%), 15 (13.1%), and 49 (42.6%) patients, respectively. During 1 year follow‐up, 51 (44.3%) patients died. Death was associated with higher APACHE II, SOFA, and VIS_max scores; higher levels of C‐reactive protein and phenylalanine; higher incidence of atrial fibrillation and use of inotropic agents; lower cholesterol, albumin, pre‐albumin, and transferrin levels; and significant changes in pro‐inflammatory and immune cytokines. Phenylalanine levels demonstrated an area under the receiver operating characteristic curve of 0.80 for mortality, with an optimal cut‐off value set at 112 μM. Phenylalanine ≥ 112 μM was associated with a higher mortality rate than was phenylalanine < 112 μM (80.5% vs. 24.3%, P < 0.001) [hazard ratio = 5.07 (2.83–9.05), P < 0.001]. The Kaplan–Meier curves revealed that phenylalanine ≥ 112 μM was associated with a lower accumulative survival rate (log rank = 36.9, P < 0.001). Higher phenylalanine levels were correlated with higher APACHE II and SOFA scores, higher C‐reactive protein levels and incidence of using inotropic agents, and changes in cytokines suggestive of immunosuppression, but lower levels of pre‐albumin and transferrin. Further multivariable analysis showed that phenylalanine ≥ 112 μM predicted death over 1 year independently of age, APACHE II and SOFA scores, atrial fibrillation, C‐reactive protein, cholesterol, pre‐albumin, transferrin, and interleukin‐8 and interleukin‐10.

Conclusions

Elevated phenylalanine levels predicted mortality in critical patients, phenotypically predominantly presenting with HF, independently of traditional prognostic factors and cytokines associated with inflammation and immunity.

Association between nutrition support and acute gastrointestinal injury in critically ill patients during the first 72 hours

BACKGROUND & AIMS

The impact of nutrition support on patients with acute gastrointestinal injury (AGI) has not been fully determined. This study aimed to 1) investigate the relationship between nutrition support and AGI, as well as nutrition support and prognosis in critically ill AGI patients and 2) evaluate the prognostic benefits of nutrition support in different severity categories of AGI patients.

METHODS

This prospective study included 379 patients in whom AGI occurred in the first 72 h after admission from 12 teaching hospitals in China. Clinical characteristics including demographics, APACHE II score, modified NUTRIC score, SOFA score, calories of nutrition, and 7 and 28-day mortality were recorded. Multiple logistic regression analysis was applied to identify the risk factors for mortality. The survival benefit of nutrition support as reflected by calories of nutrition in 72 h was evaluated for patients categorized according to their APACHE II, modified NUTRIC, and SOFA scores.

RESULTS

Patients were classified into Grades I (n = 141), II (n = 173), III (n = 48), and IV (n = 17). Significant differences were observed among different AGI grade cohorts (I-IV) in terms of APACHE II, SOFA, and modified NUTRIC scores and calories of enteral nutrition (EN), parenteral nutrition (PN), and EN + PN. Ordinal logistic regression analysis showed that only SOFA score was an independent risk factor for AGI grades (P < 0.001). APACHE II score, mechanical ventilation (MV), AGI grades, and calories of EN + PN intake were independent risk factors for 28-d mortality. Increased nutritional intake was associated with reduced mortality in severely ill patients with APACHE II scores ≥15 (P = 0.007).

CONCLUSIONS

AGI grade affected the intake of calories and was one of the risk factors for 28-d mortality. The nutrition intake of patients with AGI grade III to IV was almost only PN. The positive association between nutrition support and prognosis was more apparent in AGI patients with higher APACHE II scores.

Assisted mechanical ventilation promotes recovery of diaphragmatic thickness in critically ill patients: a prospective observational study

BACKGROUND

Diaphragm atrophy and dysfunction are consequences of mechanical ventilation and are determinants of clinical outcomes. We hypothesize that partial preservation of diaphragm function, such as during assisted modes of ventilation, will restore diaphragm thickness. We also aim to correlate the changes in diaphragm thickness and function to outcomes and clinical factors.

METHODS

This is a prospective, multicentre, observational study. Patients mechanically ventilated for more than 48 h in controlled mode and eventually switched to assisted ventilation were enrolled. Diaphragm ultrasound and clinical data collection were performed every 48 h until discharge or death. A threshold of 10% was used to define thinning during controlled and recovery of thickness during assisted ventilation. Patients were also classified based on the level of diaphragm activity during assisted ventilation. We evaluated the association between changes in diaphragm thickness and activity and clinical outcomes and data, such as ventilation parameters.

RESULTS

Sixty-two patients ventilated in controlled mode and then switched to the assisted mode of ventilation were enrolled. Diaphragm thickness significantly decreased during controlled ventilation (1.84 ± 0.44 to 1.49 ± 0.37 mm, p < 0.001) and was partially restored during assisted ventilation (1.49 ± 0.37 to 1.75 ± 0.43 mm, p < 0.001). A diaphragm thinning of more than 10% was associated with longer duration of controlled ventilation (10 [5, 15] versus 5 [4, 8.5] days, p = 0.004) and higher PEEP levels (12.6 ± 4 versus 10.4 ± 4 cmH₂O, p = 0.034). An increase in diaphragm thickness of more than 10% during assisted ventilation was not associated with any clinical outcome but with lower respiratory rate (16.7 ± 3.2 versus 19.2 ± 4 bpm, p = 0.019) and Rapid Shallow Breathing Index (37 ± 11 versus 44 ± 13, p = 0.029) and with higher Pressure Muscle Index (2 [0.5, 3] versus 0.4 [0, 1.9], p = 0.024). Change in diaphragm thickness was not related to diaphragm function expressed as diaphragm thickening fraction.

CONCLUSION

Mode of ventilation affects diaphragm thickness, and preservation of diaphragmatic contraction, as during assisted modes, can partially reverse the muscle atrophy process. Avoiding a strenuous inspiratory work, as measured by Rapid Shallow Breathing Index and Pressure Muscle Index, may help diaphragm thickness restoration.