Longitudinal Profiles of Metabolism and Bioenergetics Associated with Innate Immune Hormonal Inflammatory Responses and Amino-Acid Kinetics in Severe Sepsis and Systemic Inflammatory Response Syndrome in Children

Personalized Nutrition in the Pediatric ICU: Steering the Shift from Acute Stress to Metabolic Recovery and Rehabilitation

BACKGROUND

Nutrition significantly impacts the outcomes of critically ill children in intensive care units (ICUs). Due to the evolving metabolic, neuroendocrine, and immunological disorders associated with severe illness or trauma, there are dynamically changing phases of energy needs requiring tailored macronutrient intake.

OBJECTIVES

This study aims to assess the changing dietary needs from the acute phase through recovery, provide recommendations for implementing evidence-based strategies to ensure adequate energy and nutrient provision in pediatric ICUs, and optimize patient outcomes.

METHODS

A comprehensive search of the MEDLINE-PubMed database was conducted, focusing on randomized controlled trials, meta-analyses, and systematic reviews related to the nutrition of critically ill children. The study highlights recent guidelines using the GRADE approach, supplemented by relevant adult studies, current clinical practices, challenges, gaps in knowledge, and future directions for research aimed at improving nutritional interventions.

RESULTS

Early personalized, incremental enteral feeding helps mitigate the negative energy balance during the acute phase, aids organ function restoration in the stabilization phase, and supports growth during the recovery phase and beyond. Conversely, early full nutritional support, high protein doses, or isolated micronutrient administration have not demonstrated benefits due to anabolic resistance in these patients. Moreover, early parenteral nutrition during the acute phase may suppress autophagy and lead to worse outcomes. Accurate assessment of nutritional status and monitoring of daily energy and protein needs are crucial.

CONCLUSIONS

Strong evidence supports the establishment of a dedicated nutritional team and the implementation of individualized nutritional protocols in the ICU to reduce morbidity and mortality in critically ill children.

Alanine, a potential amino acid biomarker of pediatric sepsis: a pilot study in PICU

Sepsis is characterized by a metabolic disorder of amino acid occurs in the early stage; however, the profile of serum amino acids and their alterations associated with the onset of sepsis remain unclear. Thus, our objective is to identify the specific kinds of amino acids as diagnostic biomarkers in pediatric patients with sepsis. Serum samples were collected from patients with sepsis admitted to the pediatric intensive care unit (PICU) between January 2019 and December 2019 on the 1st, 3rd and 7th day following admission. Demographic and laboratory variables were also retrieved from the medical records specified times. Serum amino acid concentrations were detected by UPLC-MS/MS system. PLS-DA (VIP > 1.0) and Kruskal-Wallis test (p < 0.05) were employed to identify potential biomarkers. Spearman's rank correlation analysis was conducted to find the potential association between amino acid levels and clinical features. The diagnostic utility for pediatric sepsis was assessed using receiver operating characteristic (ROC) curve analysis. Most of amino acid contents in serum were significantly decreased in patients with sepsis, but approached normal levels by the seventh day post-diagnosis. Threonine (THR), lysine (LYS), valine (VAL) and alanine (ALA) emerged as potential biomarkers related for sepsis occurrence, though they were not associated with PELOD/PELOD-2 scores. Moreover, alterations in serum THR, LYS and ALA were linked to complications of brain injury, and serum ALA levels were also related to sepsis-associated acute kidney injury. Further analysis revealed that ALA was significantly correlated with the Glasgow score, serum lactate and glucose levels, C-reactive protein (CRP), and other indicators for liver or kidney dysfunction. Notably, the area under the ROC curve (AUC) for ALA in distinguishing sepsis from healthy controls was 0.977 (95% CI: 0.925-1.000). The serum amino acid profile of children with sepsis is significantly altered compared to that of healthy controls. Notably, ALA shows promise as a potential biomarker for the early diagnosis in septic children.

Fecal microbiota transplantation and short-chain fatty acids reduce sepsis mortality by remodeling antibiotic-induced gut microbiota disturbances

Objective

Sepsis is the leading cause of death in critically ill patients. The gastrointestinal tract has long been thought to play an important role in the pathophysiology of sepsis. Antibiotic therapy can reduce a patient's commensal bacterial population and raise their risk of developing subsequent illnesses, where gut microbiota dysbiosis may be a key factor.

Methods

In this study, we analyzed the 16S rRNA of fecal samples from both healthy people and patients with sepsis to determine if alterations in gut bacteria are associated with sepsis. Then, we developed a mouse model of sepsis using cecal ligation and puncture (CLP) in order to examine the effects of fecal microbiota transplantation (FMT) and short-chain fatty acids (SCFAs) on survival rate, systemic inflammatory response, gut microbiota, and mucosal barrier function.

Results

Sepsis patients' gut microbiota composition significantly differed from that of healthy people. At the phylum level, the amount of Proteobacteria in the intestinal flora of sepsis patients was much larger than that of the control group, whereas the number of Firmicutes was significantly lower. Mice with gut microbiota disorders (ANC group) were found to have an elevated risk of death, inflammation, and organ failure as compared to CLP mice. However, all of these could be reversed by FMT and SCFAs. FMT and SCFAs could regulate the abundance of bacteria such as Firmicutes, Proteobacteria, Escherichia Shigella, and Lactobacillus, restoring them to levels comparable to those of healthy mice. In addition, they increased the expression of the Occludin protein in the colon of mice with sepsis, downregulated the expression of the NLRP3 and GSDMD-N proteins, and reduced the release of the inflammatory factors IL-1β and IL-18 to inhibit cell pyroptosis, ultimately playing a protective role in sepsis.

Disccusion

FMT and SCFAs provide a microbe-related survival benefit in a mouse model of sepsis, suggesting that they may be a viable treatment for sepsis.

Ex Vivo Evaluation of Glutamine Treatment in Sepsis and Trauma in a Human Peripheral Blood Mononuclear Cells Model

We aimed to assess the lipopolysaccharide (LPS), or heat shock (HS) induction, and glutamine-modulating effects on heat shock protein-90α (HSP90α) and cytokines in an ex vivo model using peripheral blood mononuclear cells (PBMCs). The PBMCs of patients with septic shock, trauma-related systemic inflammatory response syndrome (SIRS), and healthy subjects were incubated with 1 μg/mL LPS at 43 °C (HS). Glutamine 10 mM was added 1 hour before or after induction or not at all. We measured mRNA HSP90α, monocyte (m) and lymphocyte (l) HSP90α proteins, interleukin (IL)-1b, -6, -8, -10, tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) supernatant levels. Heat shock increased the HSP90α mRNA and mHSP90α in all groups (10-fold in sepsis, p < 0.001 and p = 0.047, respectively). LPS induced the mHSP90α and lHSP90α in healthy (p < 0.001) and mHSP90α in SIRS (p = 0.004) but not in sepsis. LPS induced the cytokines at 24 and 48 h in all groups, especially in trauma (p < 0.001); HS only induced the IL-8 in healthy (p = 0.003) and septic subjects (p = 0.05). Glutamine at 10 mM before or after stimulation did not alter any induction effect of LPS or HS on HSP90α mRNA and mHSP90α protein in sepsis. In SIRS, glutamine before LPS decreased the mHSP90α but increased it when given after HS (p = 0.018). Before or after LPS (p = 0.049) and before HS (p = 0.018), glutamine decreased the lHSP90α expression in sepsis but increased it in SIRS when given after HS (p = 0.003). Regarding cytokines, glutamine enhanced the LPS-induced MCP-1 at 48 h in healthy (p = 0.011), SIRS (p < 0.001), and sepsis (p = 0.006). In conclusion, glutamine at 10 mM, before or after LPS and HS, modulates mHSP90α and lHSP90α in sepsis and SIRS differently and unpredictably. Although it does not alter the stimulation effect on interleukins, glutamine enhances the LPS induction effect on supernatant MCP-1 in all groups. Future research should seek to elucidate better the impact of glutamine and temperature modulation on HSP90α and MCP-1 pathways in sepsis and trauma.

External Validation with Accuracy Confounders of VCO2-Derived Predicted Energy Expenditure Compared to Resting Energy Expenditure Measured by Indirect Calorimetry in Mechanically Ventilated Children

Optimal energy provision, guided by measured resting energy expenditure (REE) and determined by indirect calorimetry (IC), is fundamental in Intensive Care Units (ICU). Because IC availability is limited, methods to predict REE based on carbon dioxide production (VCO2) measurements (REEVCO2) alone have been proposed as a surrogate for REE measured by IC (REEIC). The study aimed at externally and internally validating the accuracy of the REEVCO2 as an alternative to REEIC in mechanically ventilated children. A ventilator’s integrated gas exchange module (E-COVX) was used to prospectively measure REEIC and predict REEVCO2 on 107 mechanically ventilated children during the first 24 h of admission. The accuracy of the REEVCO2 compared to REEIC was assessed through the calculation of bias and precision, paired median differences, linear regression, and ROC analysis. Accuracy within ±10% of the REEIC was deemed acceptable for the REEVCO2 equation. The calculated REEVCO2 based on respiratory quotient (RQ) 0.89 resulted in a mean bias of −72.7 kcal/day (95% limits of agreement −321.7 to 176.3 kcal/day) and a high coefficient of variation (174.7%), while 51.4% of the calculations fell outside the ±10% accuracy rate. REEVCO2 derived from RQ 0.80 or 0.85 did not improve accuracy. Only measured RQ (Beta 0.73, p < 0.001) and no-recorded neuromuscular blocking agents (Beta −0.13, p = 0.044) were independently associated with the REEVCO2−REEIC difference. Among the recorded anthropometric, metabolic, nutrition, or clinical variables, only measured RQ was a strong predictor of REEVCO2 inaccuracy (p < 0.001). Cutoffs of RQ = 0.80 predicted 89% of underestimated REEIC (sensitivity 0.99; specificity 0.89) and RQ = 0.82 predicted 56% of overestimated REEIC (sensitivity of 0.99; specificity 0.56). REEVCO2 cannot be recommended as an alternative to REEIC in mechanically ventilated children, regardless of the metabolic, anthropometric, or clinical status at the time of the evaluation.

External Validation of Equations to Estimate Resting Energy Expenditure in Critically Ill Children and Adolescents with and without Malnutrition: A Cross-Sectional Study

We evaluated the validity of sixteen predictive energy expenditure equations for resting energy expenditure estimation (eREE) against measured resting energy expenditure using indirect calorimetry (REEIC) in 153 critically ill children. Predictive equations were included based on weight, height, sex, and age. The agreement between eREE and REEIC was analyzed using the Bland−Altman method. Precision was defined by the 95% limits of the agreement; differences > ±10% from REEIC were considered clinically unacceptable. The reliability was assessed by the intraclass correlation coefficient (Cronbach’s alpha). The influence of anthropometric, nutritional, and clinical variables on REEIC was also assessed. Thirty (19.6%) of the 153 enrolled patients were malnourished (19.6%), and fifty-four were overweight (10.5%) or obese (24.8%). All patients received sedation and analgesia. Mortality was 3.9%. The calculated eREE either underestimated (median 606, IQR 512; 784 kcal/day) or overestimated (1126.6, 929; 1340 kcal/day) REEIC compared with indirect calorimetry (928.3, 651; 1239 kcal/day). These differences resulted in significant biases of −342 to 592 kcal (95% limits of agreement (precision)−1107 to 1380 kcal/day) and high coefficients of variation (up to 1242%). Although predicted equations exhibited moderate reliability, the clinically acceptable ±10% accuracy rate ranged from only 6.5% to a maximum of 24.2%, with the inaccuracy varying from −31% to +71.5% of the measured patient’s energy needs. REEIC (p = 0.017) and eREE (p < 0.001) were higher in the underweight compared to overweight and obese patients. Apart from a younger age, malnutrition, clinical characteristics, temperature, vasoactive drugs, neuromuscular blockade, and energy intake did not affect REEIC and thereby predictive equations’ accuracy. Commonly used predictive equations for calculating energy needs are inaccurate for individual patients, either underestimating or overestimating REEIC compared with indirect calorimetry. Altogether these findings underscore the urgency for measuring REEIC in clinical situations where accurate knowledge of energy needs is vital.

The Effects of a Meldonium Pre-Treatment on the Course of the LPS-Induced Sepsis in Rats

A dysregulated and overwhelming response to an infection accompanied by the exaggerated pro-inflammatory state and metabolism disturbance leads to the fatal outcome in sepsis. Previously we showed that meldonium, an anti-ischemic drug clinically used to treat myocardial and cerebral ischemia, strongly increases mortality in faecal-induced peritonitis (FIP) in rats. We postulated that the same mechanism that is responsible for the otherwise strong anti-inflammatory effects of meldonium could be the culprit of the increased mortality. In the present study, we applied the LPS-induced model of sepsis to explore the presence of any differences from and/or similarities to the FIP model. When it comes to energy production, despite some shared similarities, it is evident that LPS and FIP models of sepsis differ greatly. A different profile of sympathoadrenal activation may account for this observation, as it was lacking in the FIP model, whereas in the LPS model it was strong enough to overcome the effects of meldonium. Therefore, choosing the appropriate model of sepsis induction is of great importance, especially if energy homeostasis is the main focus of the study. Even when differences in the experimental design of the two models are acknowledged, the role of different patterns of energy production cannot be excluded. On that account, our results draw attention to the importance of uninterrupted energy production in sepsis but also call for much-needed revisions of the current recommendations for its treatment.

MiR-940 Serves as a Diagnostic Biomarker in Patients with Sepsis and Regulates Sepsis-Induced Inflammation and Myocardial Dysfunction

Introduction

Sepsis is a heterogeneous syndrome with a life-long threat caused by infection. This study aimed to investigate the clinical function of miR-940 and its influence on cardiomyocyte models.

Methods

The relative expression of miR-940 was assessed by qRT-PCR and the roles in the clinical diagnosis of miR-940 were revealed by the ROC curve. The relationship between miR-940 and clinical parameters was validated by Pearson analysis. The sepsis rat models were established by treatment with cecal ligation and perforation (CLP) and clinical items including left ventricular systolic pressure (LVSP), left ventricular and end-diastolic pressure (LVEDP), maximum rate of increase/decrease in left ventricular blood pressure (± dp/dt_max) as well as troponin (cTnl), creatine kinase isoenzyme (CK-MB), TNF-α, IL-1β, and IL-6 were detected.

Results

The finding of qRT-PCR accentuated that the relative expression of miR-940 was significantly decreased in sepsis patients and CLP-stimulated models. The ROC curve proposed that miR-940 could be a satisfactory diagnostic biomarker for sepsis patients. Pearson analysis reinforced the expression of miR-940 was negatively associated with the PCT, WBC, CRP, Scr, SOFA score, and APACHE II score. The outcome of CLP-steered rat verified that overexpression of miR-940 inhibited the detrimental effects of CLP on myocardial dysfunction and inflammation reactions.

Conclusion

The downregulation of miR-940 was reported and it might be an underlying diagnostic marker in sepsis patients. Overexpression of miR-940 protected myocardial function from damage and inflammation induced by CLP.

The Effects of a Meldonium Pre-Treatment on the Course of the Faecal-Induced Sepsis in Rats

Sepsis is a life-threatening condition caused by the dysregulated and overwhelming response to infection, accompanied by an exaggerated pro-inflammatory state and lipid metabolism disturbance leading to sequential organ failure. Meldonium is an anti-ischemic and anti-inflammatory agent which negatively interferes with lipid metabolism by shifting energy production from fatty acid oxidation to glycolysis, as a less oxygen-demanding pathway. Thus, we investigated the effects of a four-week meldonium pre-treatment on faecal-induced sepsis in Sprague-Dawley male rats. Surprisingly, under septic conditions, meldonium increased animal mortality rate compared with the meldonium non-treated group. However, analysis of the tissue oxidative status did not provide support for the detrimental effects of meldonium, nor did the analysis of the tissue inflammatory status showing anti-inflammatory, anti-apoptotic, and anti-necrotic effects of meldonium. After performing tissue lipidomic analysis, we concluded that the potential cause of the meldonium harmful effect is to be found in the overall decreased lipid metabolism. The present study underlines the importance of uninterrupted energy production in sepsis, closely drawing attention to the possible harmful effects of lipid-mobilization impairment caused by certain therapeutics. This could lead to the much-needed revision of the existing guidelines in the clinical treatment of sepsis while paving the way for discovering new therapeutic approaches.

Metabolic Alterations in Sepsis

Sepsis is defined as “life-threatening organ dysfunction caused by a dysregulated host response to infection”. Contrary to the older definitions, the current one not only focuses on inflammation, but points to systemic disturbances in homeostasis, including metabolism. Sepsis leads to sepsis-induced dysfunction and mitochondrial damage, which is suggested as a major cause of cell metabolism disorders in these patients. The changes affect the metabolism of all macronutrients. The metabolism of all macronutrients is altered. A characteristic change in carbohydrate metabolism is the intensification of glycolysis, which in combination with the failure of entering pyruvate to the tricarboxylic acid cycle increases the formation of lactate. Sepsis also affects lipid metabolism—lipolysis in adipose tissue is upregulated, which leads to an increase in the level of fatty acids and triglycerides in the blood. At the same time, their use is disturbed, which may result in the accumulation of lipids and their toxic metabolites. Changes in the metabolism of ketone bodies and amino acids have also been described. Metabolic disorders in sepsis are an important area of research, both for their potential role as a target for future therapies (metabolic resuscitation) and for optimizing the current treatment, such as clinical nutrition.

Survivin and caspases serum protein levels and survivin variants mRNA expression in sepsis

Sepsis is a dysregulated host response to infection related to devastating outcomes. Recently, interest has been shifted towards apoptotic and antiapoptotic pathobiology. Apoptosis is executed through the activation of caspases regulated by a number of antiapoptotic proteins, such as survivin. The survivin and caspases’ responses to sepsis have not yet been elucidated. This is a multicenter prospective observational study concerning patients with sepsis (n = 107) compared to patients with traumatic systemic inflammatory response syndrome (SIRS) (n = 75) and to healthy controls (n = 89). The expression of survivin was quantified through real-time quantitative polymerase chain reaction for the different survivin splice variants (wild type-WT, ΔEx3, 2B, 3B) in peripheral blood leukocytes. The apoptotic or antiapoptotic tendency was specified by measuring survivin-WT, caspase-3, and -9 serum protein concentrations through enzyme-linked immunosorbent assay. The survivin-WT, -2B, -ΔΕx3 mRNA, survivin protein, and caspases showed an escalated increase in SIRS and sepsis, whereas survivin-3B was repressed in sepsis (p < 0.05). Survivin correlated with IL-8 and caspase-9 (p < 0.01). For discriminating sepsis, caspase-9 achieved the best receiver operating characteristic curve (AUROC) of 0.95. In predicting mortality, caspase-9 and survivin protein achieved an AUROC of 0.70. In conclusion, specific apoptotic and antiapoptotic pathways might represent attractive targets for future research in sepsis.

Energy Expenditure in Mechanically Ventilated Korean Children: Single-Center Evaluation of a New Estimation Equation

OBJECTIVES

Accurate assessments of energy expenditure are vital for determining optimal nutritional support, especially in critically ill children. We evaluated current methods for energy expenditure prediction, in comparison with indirect calorimetry, and developed a new estimation equation for mechanically ventilated, critically ill Korean children.

DESIGN

Single-center retrospective study.

SETTING

Fourteen-bed pediatric medical ICU in a tertiary care children's hospital.

PATIENTS

Pediatric patients admitted to the PICU between October 2017 and September 2019 with a measured energy expenditure by indirect calorimetry.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total 95 pediatric patients (70 in derivation cohort for development of a new predictive equation and 25 in validation cohort) were included. Mean measured energy expenditure of group A was 66.20 ± 15.35 kcal/kg/d. All previously established predictive equations underestimated the predicted energy expenditure, compared with the measured energy expenditure, except the Food and Agriculture/World Health Organization/United Nations University equation. The Schofield-Height and Weight equation showed the best performance among the tested predictive equations for the entire cohort (least bias, -68.58 kcal/d; best percentage, 108.46% ± 33.60%) compared with the measured energy expenditure. It was also the best performing predictive equation in subgroup analysis by age, sex, nutritional status, and organ failure. Because some discrepancies remained between the measured energy expenditure and predicted energy expenditures, we developed a new estimation equation using multiple regression analysis and those variables significantly associated with our current measured energy expenditures: Energy expenditure = -321.264 + 72.152 × (body weight, kg)-1.396 × (body weight) + 5.668 × height (cm) + organ dysfunction* (*hematologic, 76.699; neurologic, -87.984). This new estimation equation showed the least bias and best percentage compared with previous predictive equations (least bias, 15.51 kcal/d; best percentage, 102.30% ± 28.10%).

CONCLUSIONS

There are significant disparities between measured and calculated energy expenditures. We developed a new estimation equation based on measured energy expenditure data that shows better performance in mechanically ventilated Korean children than other equations. This new estimation equation requires further prospective validation in pediatric series with a range in body habitus.

A single dose of eHSP72 attenuates sepsis severity in mice

High levels of extracellular 72 kDa heat shock protein (eHSP72) can be detected in the serum of septic patients and are associated with increased oxidative profiles and elevated rates of mortality among these patients. However, a possible immunomodulatory role for this protein, resulting in tissue protection during sepsis, has never been assessed. In this study, we investigated whether eHSP72 administration could attenuate the severity of sepsis in a mouse peritonitis model. Animals (90-day-old male C57BL/6J mice) were divided into Sepsis (n = 8) and Sepsis + eHSP72 (n = 9) groups, which both received injections of 20% fecal solution [1 mg/g body weight (wt), intraperitoneal (i.p.)], to trigger peritonitis induced-sepsis, whereas a Control group (n = 7) received a saline injection. eHSP72 was administered (1.33 ng/g body wt) to the Sepsis+eHSP72 group, 12 h after sepsis induction. All animals were evaluated for murine sepsis score (MSS), hemogram, core temperature, and glycemia (before and 4, 12, and 24 h after sepsis induction). Treatment with eHSP72 promoted reduced sepsis severity 24 h after sepsis induction, based on MSS scores (Control = 1.14 ± 1.02; Sepsis = 11.07 ± 7.24, and Sepsis + eHSP72 = 5.62 ± 1.72, P < 0.001) and core temperatures (°C; Control = 37.48 ± 0.58; Sepsis = 35.17 ± 2.88, and Sepsis + eHSP72 = 36.94 ± 2.02; P = 0.006). eHSP72 treatment also limited the oxidative profile and respiratory dysfunction in mice with sepsis. Although sepsis modified glycemic levels and white and red blood cell counts, these variables were not influenced by eHSP72 treatment (P > 0.05). Finally, eHSP72 improved the survival rate after sepsis (P = 0.0371). Together, our results indicated that eHSP72 may ameliorate sepsis severity and possibly improve some sepsis indices in mice.

Nutritional Status Deterioration Occurs Frequently During Children's ICU Stay

OBJECTIVES

Malnutrition and faltering growth at PICU admission have been related to suboptimal outcomes. However, little is known about nutritional status deterioration during PICU stay, as critical illness is characterized by a profound and complex metabolism shift, which affects energy requirements and protein turnover. We aim to describe faltering growth occurrence during PICU stay.

DESIGN

Single-center prospective observational study.

SETTING

Twenty-three-bed general PICU, Lyon, France.

PATIENTS

All critically ill children 0-18 years old with length of stay longer than 5 days were included (September 2013-December 2015).

INTERVENTIONS

Weight and height/length were measured at admission, and weight was monitored during PICU stay, in order to calculate body mass index for age z score. Faltering growth was defined as body mass index z score decline over PICU stay. Children admitted during the first year of the study and who presented with faltering growth were followed after PICU discharge for 3 months.

MEASUREMENTS AND MAIN RESULTS

We analyzed 579 admissions. Of them, 10.2% presented a body mass index z score decline greater than 1 SD and 27.8% greater than 0.5. Admission severity risk scores and prolonged PICU stay accounted for 4% of the variability in nutritional status deterioration. Follow-up of post-PICU discharge nutritional status showed recovery within 3 months in most patients.

CONCLUSIONS

Nutritional deterioration is frequent and often intense in critically ill children with length of stay greater than 5 days. Future research should focus on how targeted nutritional therapies can minimize PICU faltering growth and improve post-PICU rehabilitation.

Impact of the route of nutrition on gut mucosa in ventilated adults with shock: an ancillary of the NUTRIREA-2 trial

PURPOSE

The effects of the route of nutrition on the gut mucosa of patients with shock are unclear. Plasma citrulline concentration is a marker of enterocyte mass, and plasma intestinal fatty acid binding protein (I-FABP) concentration is a marker of enterocyte damage. We aimed to study the effect of the route of nutrition on plasma citrulline concentration measured at day 3 of nutrition.

MATERIALS AND METHODS

Ancillary study of the NUTRIREA-2 trial. Ventilated adults with shock were randomly assigned to receive enteral or parenteral nutrition. Enterocyte biomarkers were measured at baseline, day 3, and day 8 of nutrition.

RESULT

A total of 165 patients from 13 French ICUs were included in the study: 85 patients in the enteral group and 80 patients in the parenteral group. At baseline, plasma citrulline was low without difference between groups (12.2 µmol L^-1 vs 13.3 µmol L^-1). At day 3, plasma citrulline concentration was higher in the enteral group than in the parenteral group (18.7 µmol L^-1 vs 15.3 µmol L^-1, p = 0.01). Plasma I-FABP concentration was increased at baseline, without difference between groups (245 pg mL^-1 vs 244 pg mL^-1). Plasma I-FABP concentration was higher in the enteral group than in the parenteral group at day 3 and day 8 (158 pg mL^-1 vs 50 pg mL^-1, p = 0.005 and 225 pg mL^-1 vs 50 pg mL^-1, p = 0.03).

CONCLUSION

Plasma citrulline concentration was higher after 3 days of enteral nutrition than after 3 days of parenteral nutrition. This result raises the question of the possibility that enteral nutrition is associated with a more rapid restoration of enterocyte mass than parenteral nutrition.

The importance of bioelectrical impedance in the critical pediatric patient

BACKGROUND & AIMS

Sepsis is still a significant cause of death in the Intensive Care Unit and its early diagnosis is vital. Changes in cell permeability have been observed early in sepsis. Lower values of bioelectrical impedance (BIA) such as reactance adjusted by height (Xc/H) and phase angle (PA) have already been studied as a prognostic biomarker for many diseases and may indicate cell injury. BIA is a low cost, practical, noninvasive method that can be measured at bedside. This study investigated the utility of PA and Xc/H raw values in the pediatric critical care unit as predictors of progression to septic shock, as a clinical monitoring tool and to support the diagnosis of septic shock.

METHODS

We prospectively analyzed bioelectrical impedance in 145 children aged between one month and six years who were not in septic shock on admission to the intensive care unit Serial bioelectrical impedance analysis (BIA) measures were analyzed to determine the sensitivity and specificity of accurately identifying children who subsequently developed septic shock. Kaplan-Meier septic shock-free survival curves modeled by Xc/H and PA were done.

RESULTS

The free-septic shock survival curve analysis showed that patients with the lowest median values of Xc/H and PA were associated with the highest percentage of occurrence of septic shock (p = 0.0001 for Xc/H and <0.0006 for PA) and longest length of stay in the intensive care unit (p < 0.0011 for Xc/H and p < 0.004 for PA). Values of Xc/H below 48.63 Ohm/m at admission showed statistically significant odds ratio (OR) of 3.72 for developing septic shock any time during the hospitalization period, with a 87% sensitivity, 35% specificity and an area under the curve (AUC) of 0.62. The PA at admission did not show significant results. During hospitalization, patients with Xc/H below 35.72 Ohm/m were 3.38 times more likely to develop septic shock in the next day, with a sensitivity of 66.7%, a specificity of 62.3% and AUC of 0.65. PA values below 3.27 had an OR of 9.58 for a septic shock the next day with a sensitivity of 95.8%, specificity of 29.4% and AUC of 0.62. The presence of a value of Xc/H below 33 Ohm/m showed a strong association with the occurrence of septic shock on the same day of the measurement, with an OR of 11.7, as well as a value of PA below 2.64, showed an OR of 14.2.

CONCLUSIONS

The bioelectrical parameters Xc/H and phase angle have limitations in predicting septic shock as isolated biomarkers, but have a potential role as a monitoring tool in the pediatric intensive care unit. The comparative value with other biomarkers remains to be elucidated.

Late-onset sepsis caused by Gram-negative bacteria in very low birth weight infants: a systematic review

INTRODUCTION

Very low birth weight (VLBW) infants are highly susceptible to late-onset sepsis (LOS). Compared to Gram-positive bacteria, Gram-negative bacteria are less common to cause LOS, but are associated with a more severe clinical manifestation, higher mortality, and increased risk of neonatal morbidity. So far, the clinical picture of late-onset Gram-negative sepsis (LOGNS) in VLBW infants has not been elucidated. An up-to-date and thorough understanding of the clinical picture of LOGNS in VLBW infants is important to optimize current anti-sepsis protocols. Areas covered: Literature published in the last three decades was searched for data on the epidemiology, pathogen profile, risk factors, clinical manifestations, laboratory parameters, mortality, and short-term and long-term morbidity of LOGNS in VLBW infants. Expert opinion: Gram-negative bacteria are major contributors of neonatal morbidity and mortality in VLBW infants with LOS, potentially posing a significant disease burden. Unravelling the pathogen-specific clinical picture of LOGNS and the underlying mechanisms is of particular interest. VLBW infants may differ from more mature neonates in terms of disease burden and clinical course of LOGNS. Epidemiologic studies aided by advanced molecular techniques may help to develop anti-sepsis protocols specialized for VLBW infants, with strategies targeting Gram-negative bacteria.

Prevalence and Prognostic Value of Abnormal Liver Test Results in Critically Ill Children and the Impact of Delaying Parenteral Nutrition

OBJECTIVES

In the Early versus Late Parenteral Nutrition in the Pediatric ICU randomized controlled trial, delaying parenteral nutrition to beyond day 7 (late parenteral nutrition) was clinically superior to supplemental parenteral nutrition initiated within 24 hours (early parenteral nutrition), but resulted in a higher rise in bilirubin. We aimed to document prevalence and prognostic value of abnormal liver tests in the PICU and the impact hereon of withholding early parenteral nutrition.

DESIGN

Preplanned secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric ICU randomized controlled trial. Total bilirubin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, alkaline phosphatase plasma concentrations were measured systematically in PICU. Liver test analyses were adjusted for baseline characteristics including severity of illness.

SETTING

Three PICUs in Belgium, the Netherlands, and Canada.

PATIENTS

As neonatal jaundice was considered a confounder, only the 1,231 of the 1,440 Early versus Late Parenteral Nutrition in the Pediatric ICU-patients 28 days to 17 years old were included.

INTERVENTIONS

Late parenteral nutrition as compared with early parenteral nutrition.

MEASUREMENTS AND MAIN RESULTS

During the first seven PICU days, the prevalence of cholestasis (> 2 mg/dL [34.2 μmol/L] bilirubin) ranged between 3.8% and 4.9% and of hypoxic hepatitis (≥ 20-fold upper limit of normality for alanine aminotransferase and aspartate aminotransferase) between 0.8% and 2.2%, both unaffected by the use of parenteral nutrition. Throughout the first week in PICU plasma bilirubin concentrations were higher in late parenteral nutrition patients (p < 0.05), but became comparable to early parenteral nutrition patients as soon as parenteral nutrition was started on day 8. Plasma concentrations of gamma-glutamyl transpeptidase, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase were unaffected by parenteral nutrition. High day 1 plasma concentrations of gamma-glutamyl transpeptidase, alanine aminotransferase, and aspartate aminotransferase (p ≤ 0.01), but not alkaline phosphatase, were independent risk factors for PICU mortality. Day 1 plasma bilirubin concentrations displayed a U-shaped association with PICU mortality, with higher mortality associated with bilirubin less than 0.20 mg/dL and greater than 0.76 mg/dL (< 3.42 μmol/L and > 13 μmol/L) (p ≤ 0.01).

CONCLUSIONS

Overt cholestasis and hypoxic hepatitis were rare and unrelated to the nutritional strategy. However, withholding parenteral nutrition up to 1 week in PICU increased plasma bilirubin. A mild elevation of bilirubin on the first PICU day was associated with lower risk of death and may reflect a stress response, rather than true cholestasis.

Targeted Energy Intake Is the Important Determinant of Clinical Outcomes in Medical Critically Ill Patients with High Nutrition Risk

The clinical conditions of critically ill patients are highly heterogeneous; therefore, nutrient requirements should be personalized based on the patient's nutritional status. However, nutritional status is not always considered when evaluating a patient's nutritional therapy in the medical intensive care unit (ICU). We conducted a retrospective cross-sectional study to assess the effect of ICU patients' nutrition risk status on the association between energy intake and clinical outcomes (i.e., hospital, 14-day and 28-day mortality). The nutrition risk of critically ill patients was classified as either high- or low-nutrition risk using the modified Nutrition Risk in the Critically Ill score. There were 559 (75.3%) patients in the high nutrition risk group, while 183 patients were in the low nutrition risk group. Higher mean energy intake was associated with lower hospital, 14-day and 28-day mortality rates in patients with high nutrition risk; while there were no significant associations between mean energy intake and clinical outcomes in patients with low nutrition risk. Further examination of the association between amount of energy intake and clinical outcomes showed that patients with high nutrition risk who consumed at least 800 kcal/day had significantly lower hospital, 14-day and 28-day mortality rates. Although patients with low nutrition risk did not benefit from high energy intake, patients with high nutrition risk are suggested to consume at least 800 kcal/day in order to reduce their mortality rate in the medical ICU.

Association between enteral macronutrient delivery and inflammatory response in critically ill children

BACKGROUND AND AIMS

An important goal of nutrition support in paediatric critical illness is minimising catabolism. While focussing on providing full energy requirements, macronutrient balance is often neglected. Studies suggest that there is interplay between nutrition and inflammation. We aimed to assess the amount of enteral macronutrients delivered compared to estimated requirements, and the association between delivered macronutrients and systemic inflammation in critically ill children.

METHOD

We prospectively evaluated energy and macronutrient intake in critically ill children who required at least 72 h of mechanical ventilation. Data on enteral energy and macronutrient intake was collected and expressed as a percentage of the estimated requirements. Circulating levels of inflammatory cytokines were measured by ELISA and association assessed with delivery of macronutrients from the previous 24 h.

RESULTS

A total of 87 children (0-16 years) were included in this study. By day 3 the median (IQR) intake of energy, fat, carbohydrate (CHO) and protein were 75% (50-103), 85% (43-120), 63% (42-102) and 45% (23-65) respectively. We have also shown that delivery of enteral fat and protein was associated with elevation in the levels of tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6).

CONCLUSION

The inflammatory response in critically ill children is influenced by the amount of enteral fat and protein delivered. Our data suggests that within the feed delivered, fat is often higher than protein and CHO. It is crucial to take into account the proportion of macronutrients required and not only aim to achieve the energy goal.

The C-Reactive Protein/Albumin Ratio as a Predictor of Mortality in Critically Ill Patients

The C-reactive protein (CRP)/albumin ratio has recently emerged as a marker for poor prognosis or mortality across various patient groups. This study aimed to identify the association between CRP/albumin ratio and 28-day mortality and predict the accuracy of CRP/albumin ratio for 28-day mortality in medical intensive care unit (ICU) patients. This was a retrospective cohort study of 875 patients. We evaluated the prognostic value of CRP/albumin ratio to predict mortality at 28 days after ICU admission, using Cox proportional hazard model and Kaplan-Meier survival analysis. The 28-day mortality was 28.0%. In the univariate analysis, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score (p < 0.001), CRP level (p = 0.045), albumin level (p < 0.001), and CRP/albumin ratio (p = 0.032) were related to 28-day mortality. The area under the receiver operating characteristic (ROC) curve (the area under the ROC curves (AUC)) of CRP/albumin ratio was higher than that of CRP for mortality (0.594 vs. 0.567, p < 0.001). The cut-off point for CRP/albumin ratio for mortality was 34.3. On Cox proportional-hazard regression analysis, APACHE II score (hazards ratio (HR) = 1.05, 95% confidence interval (CI) = 1.04⁻1.07, p < 0.001) and CRP/albumin ratio (HR = 1.68, 95% CI = 1.27⁻2.21, p < 0.001 for high CRP/albumin ratio) were independent predictors of 28-day mortality. Higher CRP/albumin ratio was associated with increased mortality in critically ill patients.

Association between circulating levels of heat-shock protein 27 and aggressive periodontitis

Heat-shock protein (Hsp) 27 is a major intracellular molecular chaperone and controller of intracellular responses to inflammatory signals. In the extracellular space, recombinant Hsp27 has been described to exert anti-inflammatory activities. The aim of this study was to assess the association between circulating levels of Hsp27 and different types of periodontitis. Pro- and anti-inflammatory cytokines and the stress proteins Hsp27 and Hsp60 with proposed anti- and pro-inflammatory properties, respectively, were measured by two-site ELISA in the serum of patients with aggressive periodontitis (AgP, n = 30), chronic periodontitis (CP, n = 29) and periodontally healthy controls (H, n = 28). Furthermore, Hsp27 and Hsp60 levels were also measured longitudinally in 12 AgP patients at 6 time points up to 3 months after treatment. AgP patients had lower levels of Hsp27 compared to CP patients and healthy subjects (adjusted one-way ANOVA, p < 0.001, followed by post hoc Tukey HSD comparisons), while no differences in levels of Hsp60 or cytokines between the three groups were detected. In CP patients and H subjects, the systemic Hsp27 levels correlated with Hsp60 (r = 0.43, p < 0.001; r = 0.59, p < 0.001, respectively) and with pro-inflammatory cytokines TNF-α (r = 0.48, p < 0.001; r = 0.55, p < 0.001, respectively) and IL-6 (r = 0.44, p < 0.01). However, no such correlations were detected in AgP cases. No consistent temporal patterns of changes of Hsp27 concentration were detected across AgP patients following periodontal treatment. This study provides the first evidence that Hsp27 may be differentially expressed and regulated in AgP patients as compared with CP patients and healthy individuals.