Clinical characteristics associated with postoperative intestinal epithelial barrier dysfunction in children with congenital heart disease

Impaired intestinal permeability in patients with multiple sclerosis

BACKGROUND

A number of recent studies have shown that the intestinal microbiome, part of the brain-gut axis, is implicated in the pathophysiology of multiple sclerosis. An essential part of this axis, is the intestinal barrier and gastrointestinal disorders with intestinal barrier dysregulation appear to be linked to CNS demyelination, and hence involved in the etiopathogenesis of multiple sclerosis (MS).

OBJECTIVE

The aim of this study was to evaluate the integrity of the intestinal barrier in patients with clinically definite multiple sclerosis (CDMS) and clinically isolated syndrome (CIS) using two serum biomarkers, claudin-3 (CLDN3), a component of tight epithelial junctions, and intestinal fatty acid binding protein (I-FABP), a cytosolic protein in enterocytes.

METHODS

Serum levels of CLDN3 in 37 MS patients and 22 controls, and serum levels of I-FABP in 46 MS patients and 51 controls were measured using commercial ELISA kits. Complete laboratory tests excluded the presence of gluten-related disorders in all subjects. Thirty MS patients received either disease-modifying drugs (DMD), immunosuppression (IS) or corticosteroid treatment.

RESULTS

CLDN3 levels were only significantly higher in the MS patients treated with DMD or IS compared to the control group (P=0.006). There were no differences in I-FABP serum levels between the groups. Serum CLDN3 levels did not correlate with serum I-FABP levels in CDMS, in CIS patients or controls.

CONCLUSIONS

In multiple sclerosis patients, the intestinal epithelium may be impaired with increased permeability, but without significant enterocyte damage characterized by intracellular protein leakage. Based on our data, CLDN3 serum levels appear to assess intestinal dysfunction in MS patients but mainly in treated ones.

Trajectory of gut microbiota before and after pediatric cardiopulmonary bypass surgery

Background

Varied congenital heart disease (CHD) may induce gut microbiota dysbiosis due to intestinal hypoperfusion or/and hypoxemia. Microbiota dysbiosis has been found in preoperative infants and cardiopulmonary bypass (CPB) exacerbated it further. However, the trajectory of gut microbiota from pre- to early post-CPB and one-year later remains unexplored. We examined this trajectory in the two most common CHDs, i.e., left-to-right shunt (ventricular septal defect, VSD) vs. right-to-left shunt (tetralogy of Fallot, TOF).

Methods

We enrolled 13 infants with VSD and 11 with TOF, and collected fecal samples at pre- and early post-CPB. 10 and 12 age- and gender-matched healthy control infants were enrolled respectively. We also enrolled 13 and 9 gender- and CHD diagnosis- and operation-matched one-year post-CPB patients, and 8 age- and gender-matched healthy control children. 16S rRNA sequencing of fecal samples were performed.

Results

Compared to the control groups, both VSD and TOF pre-CPB groups had significantly increased Enterobacteriaceae and Shigella, and decreased Bifidobacterium (Ps ≤ 0.049). No significant change in microbial community diversity was observed between pre- and early post-CPB periods (Ps≥0.227). Compared with early post-CPB, one-year post-CPB groups had significantly increased short-chain fatty acids-producing microbes (Ps ≤ 0.025), and their microbial communities were close to that of the control group (Ps≥0.102). There was no significant difference in microbial communities between VSD and TOF groups in any of 3 periods (Ps≥0.055).

Conclusion

In children with VSD or TOF, gut microbiota dysbiosis existed preoperatively and were not significantly altered by CPB. One-year post-CPB, microbiota significantly improved towards normal. Similar microbial communities were found between children with VSD and TOF throughout the perioperative and long-term postoperative periods.

Gut barrier integrity disruption in atopic dermatitis: truth or myth-a case-control study

Background

Gut dysbiosis has been linked to the onset and progression of various diseases, including atopic dermatitis, by disrupting the intestinal barrier integrity. In turn, it allows the translocation of microbes and toxins into the systemic circulation, which triggers an immune response.

Objectives

To measure serum levels of the gut integrity markers claudin 3 and intestinal fatty acid-binding protein in patients with atopic dermatitis.

Methods

This prospective study was conducted on 43 patients with atopic dermatitis. Healthy volunteers (n = 35) served as controls. The serum level of claudin 3 and intestinal fatty acid-binding protein were measured using an enzyme-linked immunosorbent assay for all participants.

Results

There were no significant differences in serum levels of claudin 3 and intestinal fatty acid-binding protein between patients with atopic dermatitis and the control group (P = 0.61 and 0.81, respectively). In addition, there was no significant correlation between the two markers, and different clinical and laboratory parameters (onset of disease, eczema area severity index, other allergic manifestations and serum IgE).

Conclusion

Alterations in the intestinal barrier may be absent in the ethnically distinct group of patients with atopic dermatitis included in our study. Nevertheless, our findings might have been influenced by factors such as the duration of the disease, diet and characteristics of the study population. Further studies are needed to investigate additional biomarkers or mechanisms that may be involved in atopic dermatitis pathogenesis, especially those related to the gut-skin axis.

Oxygenation and intestinal perfusion and its association with perturbations of the early life gut microbiota composition of children with congenital heart disease

Background

Early life gut microbiota is known to shape the immune system and has a crucial role in immune homeostasis. Only little is known about composition and dynamics of the intestinal microbiota in infants with congenital heart disease (CHD) and potential influencing factors.

Methods

We evaluated the intestinal microbial composition of neonates with CHD (n = 13) compared to healthy controls (HC, n = 30). Fecal samples were analyzed by shotgun metagenomics. Different approaches of statistical modeling were applied to assess the impact of influencing factors on variation in species composition. Unsupervised hierarchical clustering of the microbial composition of neonates with CHD was used to detect associations of distinct clusters with intestinal tissue oxygenation and perfusion parameters, obtained by the "oxygen to see" (O2C) method.

Results

Overall, neonates with CHD showed an intestinal core microbiota dominated by the genera Enterococcus (27%) and Staphylococcus (20%). Furthermore, a lower abundance of the genera Bacteroides (8% vs. 14%), Parabacteroides (1% vs. 3%), Bifidobacterium (4% vs. 12%), and Escherichia (8% vs. 23%) was observed in CHD compared to HCs. CHD patients that were born by vaginal delivery showed a lower fraction of the genera Bacteroides (15% vs. 21%) and Bifidobacterium (7% vs. 22%) compared to HCs and in those born by cesarean section, these genera were not found at all. In infants with CHD, we found a significant impact of oxygen saturation (SpO2) on relative abundances of the intestinal core microbiota by multivariate analysis of variance (F[8,2] = 24.9, p = 0.04). Statistical modeling suggested a large proportional shift from a microbiota dominated by the genus Streptococcus (50%) in conditions with low SpO2 towards the genus Enterococcus (61%) in conditions with high SpO2. We identified three distinct compositional microbial clusters, corresponding neonates differed significantly in intestinal blood flow and global gut perfusion.

Conclusion

Early life differences in gut microbiota of CHD neonates versus HCs are possibly linked to oxygen levels. Delivery method may affect microbiota stability. However, further studies are needed to assess the effect of potential interventions including probiotics or fecal transplants on early life microbiota perturbations in neonates with CHD.

Feeding intolerance after pediatric cardiac surgery is associated with dysbiosis, barrier dysfunction, and reduced short-chain fatty acids

Congenital heart disease (CHD) is the most common birth defect, occurring in roughly 40,000 U.S. births annually. Malnutrition and feeding intolerance (FI) in CHD range from 30% to 42% and are associated with longer hospitalization and increased mortality. Cardiopulmonary bypass (CPB) required for surgical repair of CHD induces a systemic inflammatory response worsening intestinal dysbiosis and leading to intestinal epithelial barrier dysfunction (EBD), possibly contributing to postoperative FI. The objective of this study was to determine the relationship of postoperative FI with intestinal microbiome, short-chain fatty acids (SCFAs), and EBD in pediatric CHD after cardiac surgery. This was a prospective study of patients aged 0-15 years undergoing cardiac surgery with CPB. Samples were collected preoperatively and postoperatively to evaluate the gut microbiome, plasma EBD markers, short-chain fatty acids (SCFAs), and plasma cytokines. Clinical data were collected to calculate a FI score and evaluate patient status postoperatively. We enrolled 26 CPB patients and identified FI (n = 13). Patients with FI had unique microbial shifts with the reduced SCFA-producing organisms Rothia, Clostridium innocuum, and Intestinimonas. Patients who developed FI had associated elevations in the plasma EBD markers claudin-2 (P < 0.05), claudin-3 (P < 0.01), and fatty acid binding protein (P < 0.01). Patients with FI had reduced plasma and stool SCFAs. Mediation analysis showed the microbiome functional shift was associated with reductions in stool butyric and propionic acid in patients with FI. In conclusion, we provide novel evidence that intestinal dysbiosis, markers of EBD, and SCFA depletion are associated with FI. These data will help identify mechanisms and therapeutics to improve clinical outcomes following pediatric cardiac surgery.NEW & NOTEWORTHY Feeding intolerance contributes to postoperative morbidity following pediatric cardiac surgery. The intestinal microbiome and milieu play a vital role in gut function. Short-chain fatty acids are gut and cardioprotective metabolites produced by commensal bacteria and help maintain appropriate barrier function. Depletion of these metabolites and barrier dysfunction contribute to postoperative feeding intolerance following cardiac surgery. Identifying mechanistic targets to improve the intestinal milieu with the goal of improved nutrition and clinical outcomes is critical.

Gut Microbiome in Children with Congenital Heart Disease After Cardiopulmonary Bypass Surgery (GuMiBear Study)

The gut microbiome of infants with congenital heart disease (CHD) undergoing cardiopulmonary bypass surgery (CPB) is at risk of profound alteration. The aim of this study was to examine the gut microbiome pre- and post-bypass surgery to explore potential implications of altered gut biodiversity. A prospective cohort study involving infants with CHD who underwent CPB was performed. Faecal samples were collected from infants alongside the collection of demographic and clinical data in order to examine gut microbiome changes before and after surgery. 16S rRNA sequencing analysis was performed on DNA isolated from stool samples to determine changes in gut microbiome composition. Thirty-three patients were recruited, with samples from thirteen of these available for final analysis. Compared with healthy, matched controls, at a genus level, pre-operative samples for infants with CHD demonstrated a higher relative abundance of Escherichia-Shigella (31% vs 2-6%) and a lower relative abundance of Bifidobacterium (13% vs 40-60%). In post-operative samples, the relative abundance of Escherichia-Shigella (35%), Enterococcus (11%), Akkermansia (6%), and Staphylococcus (5%) were higher than pre-op samples. One infant developed post-operative necrotising-enterocolitis (NEC). They displayed a marked abundance of the Enterococcus (93%) genus pre-operatively. This study demonstrates that infants with CHD have an altered gut microbiome when compared with healthy controls and there might be a possible link between an abundance of virulent species and NEC.

Role of Claudin- 3 as a biomarker of gut-skin axis integrity in patients with psoriasis

Increased intestinal permeability and gut dysbiosis are important factors in the pathophysiology of psoriasis and its associated conditions. Claudin-3 is a protein that is found in tight junctions and may be used to assess the integrity of the gut barrier. The aim of this study was to investigate serum concentration of Claudin- 3 (CLDN3) in patients with psoriasis. Exploring its possible relations with patients' demographic, clinical and laboratory findings was another objective. Fifty psoriatic patients and thirty-five age- and sex-matched healthy volunteers served as the study's control group in this case-control, hospital-based research. The amount of serum CLDN3 was determined by means of an enzyme-linked immunosorbent test (ELISA). Concentration of serum CLDN3 was found to be significantly higher in patients with psoriasis. (p = 0.002). There was no statistically significant correlation between CLDN3 and patient's clinical & laboratory variables. We demonstrated that gut permeability is dysfunctional in patients with psoriasis as indicated by reduction of serum CLDN3. Further investigations are needed to determine whether modulation of gut barrier may represent a new therapeutic approach for psoriasis.

Biomarkers and predictors of postoperative necrotizing enterocolitis in neonates with duct-dependent congenital heart defects undergoing cardiac surgery: a cohort study

The development of necrotizing enterocolitis (NEC) in neonates with duct-dependent congenital heart defects (CHD) who underwent cardiac surgery is accompanied by high mortality. Analysis of predictors is necessary for understanding the pathophysiology of NEC and development of approaches for prevention to achieve favorable outcomes of cardiac surgery. The purpose of the study was to develop a prognostic model for predicting the development of NEC after cardiac surgery in neonates with duct-dependent CHD. Methods. A prognostic cohort study was performed that included full-term neonates with duct-dependent CHD who underwent cardiac surgery at the Almazov National Medical Research Center from January 2021 to September 2023. The outcome was the development/absence of stage IB-III NEC in the postoperative period. Biomarkers of NEC (intestinal fatty acid binding protein (i-FABP, ng/ml), claudin-3 (CLDN3, ng/ml), calprotectin (CALPR, ng/ml), ischemia modified albumin (IMA, ng/ml), vascular endothelial growth factor A (VEGF A, pg/ml)) were measured by ELISA in the blood serum before cardiac surgery and 12-14 hours after surgery. We also analyzed clinical characteristics of neonates, C-reactive protein levels, complete blood count, abdominal ultrasound, ejection fraction (EF, Teicholtz) in the preoperative and postoperative periods, surgical parameters, P(v-a)CO2/C(a-v)O2 upon arrival from the operating room, vasoactive inotropic score (VIS) and arterial blood lactate levels in the first 24 hours after surgery. The association between predictors and the development of NEC after cardiac surgery was assessed using univariate and multivariate logistic regression analysis. Internal validation of the model was performed using 10-fold cross-validation. Results. During the observation period, 187 neonates underwent surgical treatment of duct-dependent CHD, of which 32 children developed stage IB-III NEC in the postoperative period (17.1%), two neonates required surgical treatment of NEC (6.3%). After meeting the non-inclusion and exclusion criteria, two groups of patients were formed: a main group (30 neonates who developed stages IB-III NEC in the postoperative period, of which stage III NEC was in one neonate) and a comparison group (40 neonates without NEC). Groups were comparable by types of CHD. Predictors associated with NEC (univariate analysis): intrauterine growth retardation (IUGR), formula feeding before surgery, high levels of IMA before on the first postoperative day (POD), procedures performed before surgery (Rashkind procedure/valvuloplasty/stenting), lower EF in in the early postoperative period, a higher maximum level of VIS in the first 24 hours after surgery, as well as a higher level of IR in the superior mesenteric artery (SMA) and thickening of the intestinal wall on the first postoperative day (POD) Independent preoperative predictors of NEC (AUC of model 0.885, specificity 0.867): IUGR (OR 32.2 (1.4-730.3), p=0.029), formula feeding (OR 12.6 (2.6-60.2), p=0.002), IMA level before surgery (OR 1.03 (1.01-1.04), p=0.004), CLDN3 level before surgery (OR 0.5 (0.3-0.9), p=0.013). Independent early postoperative predictors of NEC: IMA level on 12-14 hour after surgery (OR 1.02 (1.01-1.03), p=0.030), P(v-a)CO2/C(a-v)O2 immediately after surgery (OR 2.3 (1.2-4.4), p=0.008), IR>0.93 in SMA (OR 7.2 (1.6-32.4), p=0.011) and thickness of intestinal wall by ultrasound on POD 1 (OR 4.9 (1.3-19.2), p=0.021). Adding of VEGF A level (12-14 hour after surgery, negatively associated with NEC) to the model increased the specificity, but the predictor was not significant. AUC of postoperative model 0.862, specificity 0.800. The final model included preoperative (IUGR, formula feeding) and postoperative predictors (IMA, P(v-a)CO2/C(a-v)O2, IR of SMA>0.93, intestinal wall thickness), AUC=0.921, specificity 0.83. Conclusion. The identified predictors indirectly indicate the role of hypoxia in the pathophysiology of NEC in term neonates with duct-dependent CHD. Breast milk feeding/mixed feeding in the preoperative period may help reduce the risk of NEC in the postoperative period. Low levels of CLDN3 before surgery were associated with the development of NEC, but the interpretation of the result is controversial.

Gastrointestinal Biomarkers and Their Association with Feeding in the First Five Days of Pediatric Critical Illness

OBJECTIVES

Predicting the patients' tolerance to enteral nutrition (EN) would help clinicians optimize individual nutritional intake. This study investigated the course of several gastrointestinal (GI) biomarkers and their association with EN advancement (ENA) longitudinally during pediatric intensive care unit (PICU) admission.

METHODS

This is a secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric Intensive Care Unit randomized controlled trial. EN was started early and increased gradually. The cholecystokinin (CCK), leptin, glucagon, intestinal fatty acid-binding protein 2 (I-FABP2), and citrulline plasma concentrations were measured upon PICU admission, day 3 and day 5. ENA was defined as kcal EN provided as % of predicted resting energy expenditure. The course of the biomarkers and ENA was examined in patients with samples on all time points using Friedman and Wilcoxon signed-rank tests. The association of ENA with the biomarkers was examined using a 2-part mixed-effects model with data of the complete population, adjusted for possible confounders.

RESULTS

For 172 patients, median age 8.6 years (first quartile; third quartile: 4.2; 13.4), samples were available, of which 55 had samples on all time points. The median ENA was 0 (0; 0) on admission, 14.5 (0.0; 43.8) on day 3, and 28.0 (7.6; 94.8) on day 5. During PICU stay, CCK and I-FABP2 concentrations decreased significantly, whereas glucagon concentrations increased significantly, and leptin and citrulline remained stable. None of the biomarkers was longitudinally associated with ENA.

CONCLUSIONS

Based on the current evidence, CCK, leptin, glucagon, I-FABP2, and citrulline appear to have no added value in predicting ENA in the first 5 days of pediatric critical illness.

From heart to gut: Exploring the gut microbiome in congenital heart disease

Congenital heart disease (CHD) is a prevalent birth defect and a significant contributor to childhood mortality. The major characteristics of CHD include cardiovascular malformations and hemodynamical disorders. However, the impact of CHD extends beyond the circulatory system. Evidence has identified dysbiosis of the gut microbiome in patients with CHD. Chronic hypoxia and inflammation associated with CHD affect the gut microbiome, leading to alterations in its number, abundance, and composition. The gut microbiome, aside from providing essential nutrients, engages in direct interactions with the host immune system and indirect interactions via metabolites. The abnormal gut microbiome or its products can translocate into the bloodstream through an impaired gut barrier, leading to an inflammatory state. Metabolites of the gut microbiome, such as short-chain fatty acids and trimethylamine N-oxide, also play important roles in the development, treatment, and prognosis of CHD. This review discusses the role of the gut microbiome in immunity, gut barrier, neurodevelopment, and perioperative period in CHD. By fostering a better understanding of the cross-talk between CHD and the gut microbiome, this review aims to contribute to improve clinical management and outcomes for CHD patients.

Biomarkers and Functional Assays of Epithelial Barrier Disruption and Gastrointestinal Dysmotility in Critical Illness-A Narrative Review

Enteral nutrition in critically ill children has been associated with improved clinical outcomes. Gastrointestinal dysfunction often impedes the timely initiation and advancement of enteral nutrition and can contribute to immune dysregulation and systemic inflammation. Therefore, assessing gastrointestinal function, at a cellular and functional level, is important to provide optimal enteral nutrition therapy and reduce the gastrointestinal tract's contribution to the inflammatory cascade of critical illness. In this narrative review, we present an overview of biomarker and functional assays for gastrointestinal dysfunction, including epithelial barrier disruption and gastrointestinal dysmotility, that have been considered for critically ill patients.

Human Milk Feeding and Direct Breastfeeding Improve Outcomes for Infants With Single Ventricle Congenital Heart Disease: Propensity Score-Matched Analysis of the NPC-QIC Registry

Background Infants with single ventricle congenital heart disease undergo 3 staged surgeries/interventions, with risk for morbidity and mortality. We estimated the effect of human milk (HM) and direct breastfeeding on outcomes including necrotizing enterocolitis, infection-related complications, length of stay, and mortality. Methods and Results We analyzed the National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) registry (2016-2021), examining HM/breastfeeding groups during stage 1 and stage 2 palliations. We calculated propensity scores for feeding exposures, then fitted Poisson and logistic regression models to compare outcomes between propensity-matched cohorts. Participants included 2491 infants (68 sites). Estimates for all outcomes were better in HM/breastfeeding groups. Infants fed exclusive HM before stage 1 palliation (S1P) had lower odds of preoperative necrotizing enterocolitis (odds ratio [OR], 0.37 [95% CI, 0.17-0.84]; P=0.017) and shorter S1P length of stay (rate ratio [RR], 0.87 [95% CI, 0.78-0.98]; P=0.027). During the S1P hospitalization, infants with high HM had lower odds of postoperative necrotizing enterocolitis (OR, 0.28 [95% CI, 0.15-0.50]; P<0.001) and sepsis (OR, 0.29 [95% CI, 0.13-0.65]; P=0.003), and shorter S1P length of stay (RR, 0.75 [95% CI, 0.66-0.86]; P<0.001). At stage 2 palliation, infants with any HM (RR, 0.82 [95% CI, 0.69-0.97]; P=0.018) and any breastfeeding (RR, 0.71 [95% CI, 0.57-0.89]; P=0.003) experienced shorter length of stay. Conclusions Infants with single ventricle congenital heart disease in high-HM and breastfeeding groups experienced multiple significantly better outcomes. Given our findings of improved health, strategies to increase the rates of HM/breastfeeding in these patients should be implemented. Future research should replicate these findings with granular feeding data and in broader congenital heart disease populations, and should examine mechanisms (eg, HM components, microbiome) by which HM/breastfeeding benefits these infants.

Piglet cardiopulmonary bypass induces intestinal dysbiosis and barrier dysfunction associated with systemic inflammation

The intestinal microbiome is essential to human health and homeostasis, and is implicated in the pathophysiology of disease, including congenital heart disease and cardiac surgery. Improving the microbiome and reducing inflammatory metabolites may reduce systemic inflammation following cardiac surgery with cardiopulmonary bypass (CPB) to expedite recovery post-operatively. Limited research exists in this area and identifying animal models that can replicate changes in the human intestinal microbiome after CPB is necessary. We used a piglet model of CPB with two groups, CPB (n=5) and a control group with mechanical ventilation (n=7), to evaluate changes to the microbiome, intestinal barrier dysfunction and intestinal metabolites with inflammation after CPB. We identified significant changes to the microbiome, barrier dysfunction, intestinal short-chain fatty acids and eicosanoids, and elevated cytokines in the CPB/deep hypothermic circulatory arrest group compared to the control group at just 4 h after intervention. This piglet model of CPB replicates known human changes to intestinal flora and metabolite profiles, and can be used to evaluate gut interventions aimed at reducing downstream inflammation after cardiac surgery with CPB.

Human milk feeding and direct breastfeeding improve outcomes for infants with single ventricle congenital heart disease: Propensity score matched analysis of the NPC-QIC registry

Background

Infants with single ventricle (SV) congenital heart disease (CHD) undergo three staged surgeries/interventions, with risk for morbidity and mortality. We estimated the effect of human milk (HM) and direct breastfeeding (BF) on outcomes including necrotizing enterocolitis (NEC), infection-related complications, length of stay (LOS), and mortality.

Methods

We analyzed the National Pediatric Cardiology Quality Improvement Collaborative registry (2016-2021), examining HM/BF groups during stage 1 (S1P) and stage 2 (S2P) palliations. We calculated propensity scores for feeding exposures, then fitted Poisson and logistic regression models to compare outcomes between propensity-matched cohorts.

Results

Participants included 2491 infants (68 sites). Estimates for all outcomes were better in HM/BF groups. Infants fed exclusive HM before S1P had lower odds of preoperative NEC (OR=0.37, 95% CI=0.17-0.84, p=0.017) and shorter S1P LOS (RR=0.87, 0.78-0.98, p=0.027). During the S1P hospitalization, infants with high HM had lower odds of postoperative NEC (OR=0.28, 0.15-0.50, p<0.001) and sepsis (0.29, 0.13-0.65, p=0.003), and shorter S1P LOS (RR=0.75, 0.66-0.86, p<0.001). At S2P, infants with any HM (0.82, 0.69-0.97, p=0.018) and any BF (0.71, 0.57-0.89, p=0.003) experienced shorter LOS.

Conclusions

Infants with SV CHD in high HM and BF groups experienced multiple significantly better outcomes. Given our findings of improved health, strategies to increase the rates of HM/BF in these patients should be implemented. Future research should replicate these findings with granular feeding data and in broader CHD populations, and should examine mechanisms (eg, HM components; microbiome) by which HM/BF benefits these infants.

Clinical Perspective

What is new?: This is the first large, multisite study examining the impact of human milk and breastfeeding on outcomes for infants with single ventricle congenital heart disease.All outcome estimates were better in high human milk and breastfeeding groups, with significantly lower odds of necrotizing enterocolitis, sepsis, and infection-related complications; and significantly shorter length of stay at both the neonatal stage 1 palliation and the subsequent stage 2 palliation.All estimates of all-cause mortality were substantially lower in human milk and breastfeeding groups, with clinically important estimates of 75%-100% lower odds of mortality in direct breastfeeding groups.What are the clinical implications?: There is a critical need for improved, condition-specific lactation support to address the low prevalence of human milk and breastfeeding for infants with single ventricle congenital heart disease.Increasing the dose and duration of human milk and direct breastfeeding has strong potential to substantially improve the health outcomes of these vulnerable infants.

Protocol for a prospective cohort study exploring the gut microbiota of infants with congenital heart disease undergoing cardiopulmonary bypass (the GuMiBear study)

INTRODUCTION

The gut microbiota develops from birth and matures significantly during the first 24 months of life, playing a major role in infant health and development. The composition of the gut microbiota is influenced by several factors including mode of delivery, gestational age, feed type and treatment with antibiotics. Alterations in the pattern of gut microbiota development and composition can be associated with illness and compromised health outcomes.Infants diagnosed with 'congenital heart disease' (CHD) often require surgery involving cardiopulmonary bypass (CPB) early in life. The impact of this type of surgery on the integrity of the gut microbiome is poorly understood. In addition, these infants are at significant risk of developing the potentially devastating intestinal condition necrotising enterocolitis.

METHODS AND ANALYSIS

This study will employ a prospective cohort study methodology to investigate the gut microbiota and urine metabolome of infants with CHD undergoing surgery involving CPB. Stool and urine samples, demographic and clinical data will be collected from eligible infants based at the National Centre for Paediatric Cardiac Surgery in Ireland. Shotgun metagenome sequencing will be performed on stool samples and urine metabolomic analysis will identify metabolic biomarkers. The impact of the underlying diagnosis, surgery involving CPB, and the influence of environmental factors will be explored. Data from healthy age-matched infants from the INFANTMET study will serve as a control for this study.

ETHICS AND DISSEMINATION

This study has received full ethical approval from the Clinical Research Ethics Committee of Children's Health Ireland, GEN/826/20.

Research progress of tight junction protein claudin-3 in hepatobiliary systemic diseases

Claudin-3 is an important member of the claudin family of tight junction proteins and is the most abundant tight junction protein in the hepatobiliary system. It plays an important role in building tight junctions of hepatobiliary cells, and maintaining cellular barrier function and molecular delivery function. Dysregulation of hepatic claudin-3 expression leads to disruption of hepatobiliary system junctions, metabolic function, barrier function, proliferation capacity, and molecular delivery function, and is closely related to the development of various hepatobiliary diseases such as hepatic malignancies, cholesterol stones, and chronic liver diseases. In this paper, we review the progress in the research of claudin-3 in hepatobiliary diseases.

Orthopedic Surgery Causes Gut Microbiome Dysbiosis and Intestinal Barrier Dysfunction in Prodromal Alzheimer Disease Patients: A Prospective Observational Cohort Study

OBJECTIVE

To investigate gut microbiota and intestinal barrier function changes after orthopedic surgery in elderly patients with either normal cognition (NC) or a prodromal Alzheimer disease phenotype (pAD) comprising either subjective cognitive decline (SCD) or amnestic mild cognitive impairment (aMCI).

BACKGROUND

Homeostatic disturbances induced by surgical trauma and/or stress can potentially alter the gut microbiota and intestinal barrier function in elderly patients before and after orthopedic surgery.

METHODS

In this prospective cohort study, 135 patients were subject to preoperative neuropsychological assessment and then classified into: NC (n=40), SCD (n=58), or aMCI (n=37). Their gut microbiota, bacterial endotoxin (lipopolysaccharide), tight junction (TJ) protein, and inflammatory cytokines in blood were measured before surgery and on postsurgical day 1, 3, and 7 (or before discharge).

RESULTS

The short-chain fatty acid (SCFA)-producing bacteria were lower while the gram-negative bacteria, lipopolysaccharide and TJ were higher preoperatively in both the SCD and aMCI (pAD) groups compared with the NC group. After surgery, a decrease in SCFA-producing bacteria, and an increase in both gram-negative bacteria and plasma claudin were significant in the pAD groups relative to the NC group. SCFA-producing bacteria were negatively correlated with TJ and cytokines in pAD patients on postsurgical day 7. Furthermore, surgery-induced perioperative metabolic stress and inflammatory responses were associated with gut microbiota alterations.

CONCLUSIONS

Surgery exacerbates both preexisting microbiota dysbiosis and intestinal barrier dysfunction in pAD patients, all of which may be associated with systemic inflammation and, in turn, may lead to further cognitive deterioration.

Gastrointestinal Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

CONTEXT

Prior criteria to define pediatric multiple organ dysfunction syndrome (MODS) did not include gastrointestinal dysfunction.

OBJECTIVES

Our objective was to evaluate current evidence and to develop consensus criteria for gastrointestinal dysfunction in critically ill children.

DATA SOURCES

Electronic searches of PubMed and EMBASE were conducted from January 1992 to January 2020, using medical subject heading terms and text words to define gastrointestinal dysfunction, pediatric critical illness, and outcomes.

STUDY SELECTION

Studies were included if they evaluated critically ill children with gastrointestinal dysfunction, performance characteristics of assessment/scoring tools to screen for gastrointestinal dysfunction, and assessed outcomes related to mortality, functional status, organ-specific outcomes, or other patient-centered outcomes. Studies of adults or premature infants, animal studies, reviews/commentaries, case series with sample size ≤10, and non-English language studies with inability to determine eligibility criteria were excluded.

DATA EXTRACTION

Data were abstracted from each eligible study into a standard data extraction form along with risk of bias assessment by a task force member.

RESULTS

The systematic review supports the following criteria for severe gastrointestinal dysfunction: 1a) bowel perforation, 1b) pneumatosis intestinalis, or 1c) bowel ischemia, present on plain abdominal radiograph, computed tomography (CT) scan, magnetic resonance imaging (MRI), or gross surgical inspection, or 2) rectal sloughing of gut mucosa.

LIMITATIONS

The validity of the consensus criteria for gastrointestinal dysfunction are limited by the quantity and quality of current evidence.

CONCLUSIONS

Understanding the role of gastrointestinal dysfunction in the pathophysiology and outcomes of MODS is important in pediatric critical illness.

The microbiome’s relationship with congenital heart disease: more than a gut feeling

Patients with congenital heart disease (CHD) are at risk for developing intestinal dysbiosis and intestinal epithelial barrier dysfunction due to abnormal gut perfusion or hypoxemia in the context of low cardiac output or cyanosis. Intestinal dysbiosis may contribute to systemic inflammation thereby worsening clinical outcomes in this patient population. Despite significant advances in the management and survival of patients with CHD, morbidity remains significant and questions have arisen as to the role of the microbiome in the inflammatory process. Intestinal dysbiosis and barrier dysfunction experienced in this patient population are increasingly implicated in critical illness. This review highlights possible CHD-microbiome interactions, illustrates underlying signaling mechanisms, and discusses future directions and therapeutic translation of the basic research.

Dysbiosis and Intestinal Barrier Dysfunction in Pediatric Congenital Heart Disease Is Exacerbated Following Cardiopulmonary Bypass

There are no data evaluating the microbiome in congenital heart disease following cardiopulmonary bypass. The authors evaluated patients with congenital heart disease undergoing cardiopulmonary bypass and noncardiac patients undergoing surgery without bypass. Patients with congenital heart disease had differences in baseline microbiome compared with control subjects, and this was exacerbated following surgery with bypass. Markers of barrier dysfunction were similar for both groups at baseline, and surgery with bypass induced significant intestinal barrier dysfunction compared with control subjects. This study offers novel evidence of alterations of the microbiome in congenital heart disease and exacerbation along with intestinal barrier dysfunction following cardiopulmonary bypass.

Reliability of gastrointestinal barrier integrity and microbial translocation biomarkers at rest and following exertional heat stress

PURPOSE

Exertional heat stress adversely distrupts (GI) barrier integrity and, through subsequent microbial translocation (MT), negativly impacts health. Despite widespread application, the temporal reliability of popular GI barrier integity and MT biomarkers is poorly characterised.

METHOD

Fourteen males completed two 80-min exertional heat stress tests (EHST) separated by 7-14 days. Venous blood was drawn pre, immediately- and 1-hr post both EHSTs. GI barrier integrity was assessed using the serum Dual-Sugar Absorption Test (DSAT), Intestinal Fatty-Acid-Binding Protein (I-FABP) and Claudin-3 (CLDN-3). MT was assessed using plasma Lipopolysaccharide Binding Protein (LBP), total 16S bacterial DNA and Bacteroides DNA.

RESULTS

No GI barrier integrity or MT biomarker, except absolute Bacteroides DNA, displayed systematic trial order bias (p ≥ .05). I-FABP (trial 1 = Δ 0.834 ± 0.445 ng ml^-1 ; trial 2 = Δ 0.776 ± 0.489 ng ml^-1 ) and CLDN-3 (trial 1 = Δ 0.317 ± 0.586 ng ml^-1 ; trial 2 = Δ 0.371 ± 0.508 ng ml^-1 ) were increased post-EHST (p ≤ .01). All MT biomarkers were unchanged post-EHST. Coefficient of variation and typical error of measurement post-EHST were: 11.5% and 0.004 (ratio) for the DSAT 90-min postprobe ingestion; 12.2% and 0.004 (ratio) at 150-min postprobe ingestion; 12.1% and 0.376 ng ml^-1 for I-FABP; 4.9% and 0.342 ng ml^-1 for CLDN-3; 9.2% and 0.420 µg ml^-1 for LBP; 9.5% and 0.15 pg µl^-1 for total 16S DNA; and 54.7% and 0.032 for Bacteroides/total 16S DNA ratio.

CONCLUSION

Each GI barrier integrity and MT translocation biomarker, except Bacteroides/total 16S ratio, had acceptable reliability at rest and postexertional heat stress.

Recognizing a MIS-Chievous Cause of Acute Viral Gastroenteritis

Historically, children evaluated for vomiting and diarrhea secondary to viral enteritis have symptoms lasting 2-4 days and respond to supportive care, including oral rehydration and anti-emetics if required. Recently, within a 14-day timespan, we encountered three children with severe diarrhea who rapidly became dehydrated and went into hypotensive shock. Although SARS-CoV-2 molecular tests were negative by nasopharyngeal swab, all were later found to have MIS-C. This small case series underscores features reported in previous larger studies and emphasizes the rapid clinical evolution of this condition. We highlight the importance of early recognition of cardinal laboratory findings characteristic of MIS-C (i.e., lymphopenia, markedly elevated acute phase reactants, and hypoalbuminemia). We also show serologic evidence that the pathophysiological mechanism of SARS-CoV-2 related diarrhea may differ from other causes of dehydrating vomiting and diarrhea, with no serologic evidence of villus cell injury.

The Role of Human Milk in Decreasing Necrotizing Enterocolitis Through Modulation of the Infant Gut Microbiome: A Scoping Review

BACKGROUND

Necrotizing enterocolitis is associated with a high incidence of morbidity and mortality in premature infants. Human milk minimizes necrotizing enterocolitis risk, although the mechanism of protection is not thoroughly understood. Increasingly, dysbiosis of the infant gut microbiome, which is affected by infant diet, is hypothesized to play a role in necrotizing enterocolitis pathophysiology.

RESEARCH AIM

The aim of this scoping review was to summarize the state of the science regarding the hypothesis that the gut microbiome composition is a mediator of the relationship between human milk and decreased incidence of necrotizing enterocolitis within a sample of human infants.

METHODS

Electronic databases and reference lists were searched for peer-reviewed primary research articles addressing the link between human milk, gut microbiome composition, and subsequent incidence of necrotizing enterocolitis among human infants.

RESULTS

A total of four studies met criteria for inclusion in this review. Of these, evidence supporting the link between human milk, gut microbiome composition, and necrotizing enterocolitis was found in two (50%) studies.

CONCLUSION

Some evidence linking all three variables is provided in this review. Given the small number of available studies, and the limitations of those studies, more research is urgently needed to thoroughly understand the protection against necrotizing enterocolitis gained through the provision of human milk.

Interleukin-10 and Zonulin Are Associated With Postoperative Delayed Gastric Emptying in Critically Ill Surgical Pediatric Patients: A Prospective Pilot Study

BACKGROUND

Impaired gastric emptying (GE) is associated with morbidity in surgical critically ill children. The relationship between inflammation, gut barrier integrity (lipopolysaccharide binding protein [LBP]; zonulin), and GE has not been described in this cohort.

METHODS

Children ≥2 years of age and requiring critical care after surgery were enrolled. Preoperative and postoperative levels of serum cytokines, LBP, and zonulin, and GE by the acetaminophen absorption test, were measured, allowing patients to serve as their own controls. Postoperative delayed GE was defined as a decrease in GE by ≥20% compared with preoperative GE. The following were examined : comparison between postoperative andpreoperative values, correlations between fold change (postoperative/preoperative) in study variables, and fold change in study variables between patients with and without postoperative delayed GE.

RESULTS

Twenty patients, median age 14 years (12.25, 18), 12 female, were included. Eight of 20 patients had postoperative delayed GE. Postoperative interleukin-6 (IL-6), IL-8, IL-10, and LBP were increased, and zonulin was decreased (P-values < .05). Fold change in IL-10 and zonulin were inversely correlated (ρ -0.618, P = .004). Patients with postoperative delayed GE had greater fold increase in IL-10 (P = .0159) and fold decrease in zonulin (P = .0160). Five of 7 (71%) patients with both fold increase in IL-10 and decrease in zonulin had delayed GE.

CONCLUSION

Postoperative changes in IL-10 and zonulin were associated with delayed GE in surgical critically ill children, which might suggest a mechanism to for delayed GE in postoperative inflammation and gut barrier dysregulation after surgery.

Tissue alkaline phosphatase activity and expression in an experimental infant swine model of cardiopulmonary bypass with deep hypothermic circulatory arrest

Background

Infant cardiac surgery with cardiopulmonary bypass results in decreased circulating alkaline phosphatase that is associated with poor postoperative outcomes. Bovine intestinal alkaline phosphatase infusion represents a novel therapy for post-cardiac surgery organ injury. However, the effects of cardiopulmonary bypass and bovine-intestinal alkaline phosphatase infusion on tissue-level alkaline phosphatase activity/expression are unknown.

Methods

Infant pigs (n = 20) underwent cardiopulmonary bypass with deep hypothermic circulatory arrest followed by four hours of intensive care. Seven control animals underwent mechanical ventilation only. Cardiopulmonary bypass/deep hypothermic circulatory arrest animals were given escalating doses of bovine intestinal alkaline phosphatase infusion (0-25 U/kg/hr.; n = 5/dose). Kidney, liver, ileum, jejunum, colon, heart and lung were collected for measurement of tissue alkaline phosphatase activity and mRNA.

Results

Tissue alkaline phosphatase activity varied significantly across organs with the highest levels found in the kidney and small intestine. Cardiopulmonary bypass with deep hypothermic circulatory arrest resulted in decreased kidney alkaline phosphatase activity and increased lung alkaline phosphatase activity, with no significant changes in the other organs. Alkaline phosphatase mRNA expression was increased in both the lung and the ileum. The highest dose of bovine intestinal alkaline phosphatase resulted in increased kidney and liver tissue alkaline phosphatase activity.

Conclusions

Changes in alkaline phosphatase activity after cardiopulmonary bypass with deep hypothermic circulatory arrest and bovine intestinal alkaline phosphatase delivery are tissue specific. Kidneys, lung, and ileal alkaline phosphatase appear most affected by cardiopulmonary bypass with deep hypothermic circulatory arrest and further research is warranted to determine the mechanism and biologic importance of these changes.

Bisphenols and phthalates: Plastic chemical exposures can contribute to adverse cardiovascular health outcomes

Phthalates and bisphenols are high production volume chemicals that are used in the manufacturing of consumer and medical products. Given the ubiquity of bisphenol and phthalate chemicals in the environment, biomonitoring studies routinely detect these chemicals in 75-90% of the general population. Accumulating evidence suggests that such chemical exposures may influence human health outcomes, including cardiovascular health. These associations are particularly worrisome for sensitive populations, including fetal, infant and pediatric groups-with underdeveloped metabolic capabilities and developing organ systems. In the presented article, we aimed to review the literature on environmental and clinical exposures to bisphenols and phthalates, highlight experimental work that suggests that these chemicals may exert a negative influence on cardiovascular health, and emphasize areas of concern that relate to vulnerable pediatric groups. Gaps in our current knowledge are also discussed, so that future endeavors may resolve the relationship between chemical exposures and the impact on pediatric cardiovascular physiology.

Derangement of Arginine and Related Amino Acids in Children Undergoing Surgery for Congenital Heart Disease With Cardiopulmonary Bypass

Supplemental Digital Content is available in the text.

Arginine is a conditionally essential amino acid, the precursor for nitric oxide and a key factor in cell proliferation, protein synthesis, and energy metabolism. When there is increased demand in the setting of inflammation, ischemia-reperfusion injury, and organ dysfunction, endogenous arginine production falls short, and external supplementation may be necessary. The goal of this study was to assess changes in concentrations of plasma arginine, citrulline, ornithine, glutamine, and plasma arginase in infants and children undergoing surgery for congenital heart disease with cardiopulmonary bypass.

Nutritional support for children during critical illness: European Society of Pediatric and Neonatal Intensive Care (ESPNIC) metabolism, endocrine and nutrition section position statement and clinical recommendations

Background

Nutritional support is considered essential for the outcome of paediatric critical illness. There is a lack of methodologically sound trials to provide evidence-based guidelines leading to diverse practices in PICUs worldwide. Acknowledging these limitations, we aimed to summarize the available literature and provide practical guidance for the paediatric critical care clinicians around important clinical questions many of which are not covered by previous guidelines.

Objective

To provide an ESPNIC position statement and make clinical recommendations for the assessment and nutritional support in critically ill infants and children.

Design

The metabolism, endocrine and nutrition (MEN) section of the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) generated 15 clinical questions regarding different aspects of nutrition in critically ill children. After a systematic literature search, the Scottish Intercollegiate Guidelines Network (SIGN) grading system was applied to assess the quality of the evidence, conducting meta-analyses where possible, to generate statements and clinical recommendations, which were then voted on electronically. Strong consensus (> 95% agreement) and consensus (> 75% agreement) on these statements and recommendations was measured through modified Delphi voting rounds.

Results

The final 15 clinical questions generated a total of 7261 abstracts, of which 142 publications were identified relevant to develop 32 recommendations. A strong consensus was reached in 21 (66%) and consensus was reached in 11 (34%) of the recommendations. Only 11 meta-analyses could be performed on 5 questions.

Conclusions

We present a position statement and clinical practice recommendations. The general level of evidence of the available literature was low. We have summarised this and provided a practical guidance for the paediatric critical care clinicians around important clinical questions.

Electronic supplementary material

The online version of this article (10.1007/s00134-019-05922-5) contains supplementary material, which is available to authorized users.

Immediate Post-operative Enterocyte Injury, as Determined by Increased Circulating Intestinal Fatty Acid Binding Protein, Is Associated With Subsequent Development of Necrotizing Enterocolitis After Infant Cardiothoracic Surgery

Objectives: 1 Measure serial serum intestinal fatty acid binding protein levels in infants undergoing cardiac surgery with cardiopulmonary bypass to evaluate for evidence of early post-operative enterocyte injury. 2 Determine the association between immediate post-operative circulating intestinal fatty acid binding protein levels and subsequent development of necrotizing enterocolitis. Design: Observational cohort study. Intestinal fatty acid binding protein was measured pre-operatively, at rewarming, and at 6 and 24 h post-operatively. Percent of goal enteral kilocalories on post-operative day 5 and episodes of necrotizing enterocolitis were determined. Multivariable analysis assessed for factors independently associated with clinical feeding outcomes and suspected/definite necrotizing enterocolitis. Setting: Quaternary free-standing children's hospital pediatric cardiac intensive care unit. Patients: 103 infants <120 days of age undergoing cardiothoracic surgery with cardiopulmonary bypass. Interventions: None. Results: Median pre-operative intestinal fatty acid binding protein level was 3.93 ng/ml (range 0.24-51.32). Intestinal fatty acid binding protein levels rose significantly at rewarming (6.35 ng/ml; range 0.54-56.97; p = 0.008), continued to rise slightly by 6 h (6.57 ng/ml; range 0.75-112.04; p = 0.016), then decreased by 24 h (2.79 ng/ml; range 0.03-81.74; p < 0.0001). Sixteen subjects (15.7%) developed modified Bell criteria Stage 1 necrotizing enterocolitis and 9 subjects (8.8%) developed Stage 2 necrotizing enterocolitis. Infants who developed necrotizing enterocolitis demonstrated a significantly higher distribution of intestinal fatty acid binding protein levels at both 6 h (p = 0.005) and 24 h (p = 0.005) post-operatively. On multivariable analysis, intestinal fatty acid binding protein was not associated with percentage of goal enteral kilocalories delivered on post-operative day 5. Higher intestinal fatty acid binding protein was independently associated with subsequent development of suspected/definite necrotizing enterocolitis (4% increase in odds of developing necrotizing enterocolitis for each unit increase in intestinal fatty acid binding protein; p = 0.0015). Conclusions: Intestinal fatty acid binding protein levels rise following infant cardiopulmonary bypass, indicating early post-operative enterocyte injury. Intestinal fatty acid binding protein was not associated with percent of goal enteral nutrition achieved on post-operative day 5, likely due to protocolized feeding advancement based on clinically observable factors. Higher intestinal fatty acid binding protein at 6 h post-operatively was independently associated with subsequent development of necrotizing enterocolitis and may help identify patients at risk for this important complication.

Plasma claudin-3 is associated with tumor necrosis factor-alpha-induced intestinal endotoxemia in liver disease

OBJECTIVE

To investigate intestinal endotoxemia (IETM), intestinal permeability (IP) and cytokine activity in patients with liver cirrhosis (LC).

MATERIALS AND METHODS

Twenty-nine patients with chronic hepatitis B (CHB), 28 with compensated LC, 33 with decompensated LC, 24 with spontaneous bacterial peritonitis (SBP), 26 with acute-on-chronic liver failure (ACLF), and 24 with decompensated LC complicated by hepatocellular carcinoma (HCC) were recruited. Thirty-one healthy people were included as a control group. Plasma tumor necrosis factor (TNF)-α, interferon (IFN)-γ, D-lactate, endotoxin, and claudin-3 levels were assayed. Data were compared using Pearson correlation testing and analysis of variance, with P < 0.05 considered significant.

RESULTS

TNF-α, claudin-3, and endotoxin levels were significantly increased (P < 0.05) in the plasma of all patients with liver disease compared with that of controls, particularly in patients with decompensated LC, SBP, ACLF, or HCC (P < 0.01). IFN-γ was significantly higher in HCC than in other liver diseases (P < 0.01). Plasma D-lactate was significantly decreased in all liver diseases, except SBP (P < 0.01). TNF-α, endotoxin, and claudin-3 levels were positively correlated (P < 0.01), but correlations of IFN-γ with endotoxin or claudin-3 were not significant. The plasma D-lactate level did not significantly correlate with either TNF-α, endotoxin, or claudin-3 levels.

CONCLUSION

Plasma claudin-3, but not D-lactate, was found to be a marker of IP in patients with liver diseases. Elevated plasma TNF-α in such patients was likely to have injured the intestinal barrier, leading to IETM, especially in end-stage LC.

Alkaline Phosphatase Activity and Endotoxemia After Infant Cardiothoracic Surgery

OBJECTIVE

Infant cardiopulmonary bypass (CPB) increases intestinal permeability leading to endotoxemia. Alkaline phosphatase (AP) reduces endotoxin toxicity in vitro but its effects on endotoxemia in human disease are poorly understood. We assessed the association between serum AP activity and endotoxemia in infants undergoing CPB and determined the effect of ex vivo addition of AP on endotoxemia.

METHODS

Prospective cohort study of 62 infants ≤120 days of age undergoing CPB. AP activity and Endotoxin Activity Assay (EAA) were measured pre-operatively, during rewarming, and 24 h after cardiac intensive care unit admission. In 22 subjects, EAA was measured in pre-operative and rewarming whole blood samples with/without addition of 1,600 U/L of human liver AP.

RESULTS

AP activity decreased during CPB (mean decrease 94.8U/L; P < 0.0001). Median EAA was 0.41 pre-operation, rose to 0.52 (P < 0.05) during rewarming, and remained stably elevated at 24 h. Subjects with low pre-operative AP activity had significantly higher pre-operative (0.47 vs. 0.36; P < 0.05) and rewarming (0.59 vs. 0.43; P < 0.01) EAA with a trend toward higher EAA at 24 h (0.52 vs. 0.45; P = 0.12). Subjects with low rewarming AP activity showed similar differences that did not reach statistical significance. Ex vivo addition of human liver AP decreased pre-operative EAA by 29% (P < 0.001) and rewarming EAA by 51% (P < 0.0001).

CONCLUSION

Endotoxemia is common in infants undergoing CPB. Native AP activity and endotoxemia are inversely related and ex vivo addition of exogenous AP reduces whole blood EAA. Future research should evaluate AP as a therapy to reduce the harmful effects of endotoxemia following infant CPB.

Metabolomic Fingerprinting of Infants Undergoing Cardiopulmonary Bypass: Changes in Metabolic Pathways and Association With Mortality and Cardiac Intensive Care Unit Length of Stay

Background Mortality for infants undergoing complex cardiac surgery is >10% with a 30% to 40% risk of complications. Early identification and treatment of high-risk infants remains challenging. Metabolites are small molecules that determine the minute-to-minute cellular phenotype, making them ideal biomarkers for postsurgical monitoring and potential targets for intervention. Methods and Results We measured 165 serum metabolites by tandem mass spectroscopy in infants ≤120 days old undergoing cardiopulmonary bypass. Samples were collected prebypass, during rewarming, and 24 hours after surgery. Partial least squares-discriminant analysis, pathway analysis, and receiver operator characteristic curve analysis were used to evaluate changes in the metabolome, assess altered metabolic pathways, and discriminate between survivors/nonsurvivors as well as upper/lower 50% intensive care unit length of stay. Eighty-two infants had preoperative samples for analysis; 57 also had rewarming and 24-hour samples. Preoperation, the metabolic fingerprint of neonates differed from older infants ( R2=0.89, Q2=0.77; P<0.001). Cardiopulmonary bypass resulted in progressive, age-independent metabolic disturbance ( R2=0.92, Q2=0.83; P<0.001). Multiple pathways demonstrated changes, with arginine/proline ( P=1.2×10-35), glutathione ( P=3.3×10-39), and alanine/aspartate/glutamate ( P=1.4×10-26) metabolism most affected. Six subjects died. Nonsurvivors demonstrated altered aspartate ( P=0.007) and nicotinate/nicotinamide metabolism ( P=0.005). The combination of 24-hour aspartate and methylnicotinamide identified nonsurvivors versus survivors (area under the curve, 0.86; P<0.01), as well as upper/lower 50% intensive care unit length of stay (area under the curve, 0.89; P<0.01). Conclusions The preoperative metabolic fingerprint of neonates differed from older infants. Large metabolic shifts occurred after cardiopulmonary bypass, independent of age. Nonsurvivors and subjects requiring longer intensive care unit length of stay showed distinct changes in metabolism. Specific metabolites, including aspartate and methylnicotinamide, may differentiate sicker patients from those experiencing a more benign course.

Tight junction structure, function, and assessment in the critically ill: a systematic review

BACKGROUND

Epithelial and endothelial barrier integrity, essential for homeostasis, is maintained by cellular boarder structures known as tight junctions (TJs). In critical illness, TJs may become disrupted, resulting in barrier dysfunction manifesting as capillary leak, pulmonary edema, gut bacterial translocation, and multiple organ failure. We aim to provide a clinically focused overview of TJ structure and function and systematically review and analyze all studies assessing markers of endothelial and epithelial TJ breakdown correlated with clinical outcomes in critically ill humans.

METHODS

We systematically searched MEDLINE, EMBASE, and PubMed. Additional articles were identified by targeted searches. We included studies that looked at the relationship between biomarkers of endothelial or epithelial TJ structure or function and critical illness. Results were qualitatively analyzed due to sample size and heterogeneity.

RESULTS

A total of 5297 abstracts met search criteria, of which 150 articles met requirements for full text review. Of these, 30 studies met inclusion criteria. Fifteen of the 30 reports investigated proteins of endothelial tight junctions and 15 investigated epithelial TJ markers, exclusively in the gastrointestinal epithelium. No studies investigated TJ-derived proteins in primary cardiac or pulmonary pathology.

CONCLUSIONS

TJ integrity is essential for homeostasis. We identified multiple studies that indicate TJs are disrupted by critical illness. These studies highlight the significance of barrier disruption across many critical disease states and correlate TJ-associated markers to clinically relevant outcomes. Further study on the role of multiple tissue-specific claudins, particularly in the setting of respiratory or cardiac failure, may lead to diagnostic and therapeutic advances.

SYSTEMATIC REVIEW REGISTRATION

This systematic review is registered in the PROSPERO database: CRD42017074546 .

Endotoxin Activity in Neonates Undergoing Cardiac Surgery: Cohort Study

BACKGROUND

Endotoxemia in pediatric cardiac surgical patients is poorly understood. The endotoxin activity assay (EAA) levels were examined in neonates undergoing cardiac surgery in order to assess their reference levels and their association with other pre-, intra-, and postoperative risk factors for gut hypoperfusion. We finally observed if refeeding was associated with modification of endotoxin levels.

METHODS

In a prospective cohort study, neonates undergoing surgery for correction or palliation were enrolled. Preterm birth, weight below 1.5 kg, the need for extracorporeal membrane oxygenation, and urgent surgery were exclusion criteria.

RESULTS

Among the 26 enrolled neonates, 12 underwent on-pump and 14 off-pump surgery, 22 received a preoperative infusion of prostaglandin E2. Overall, 11 patients were surgically corrected and 15 received a palliation. Endotoxin activity assay baseline levels were inversely correlated with age at surgery ( r = -.50, P = .006) and they increased to postoperative day2 ( P = .002). On-pump versus off-pump surgery ( P =.36) and surgical palliation with a Blalock-Taussig shunt versus correction ( P = .45) did not predict increase in EAA levels. Aortic clamping for coarctation repair was associated with the lowest levels ( P = .04). Systolic, mean, and diastolic pressures were associated with EAA levels ( r = -.55, P = .01; r = -.45, P = .02; r = -.37, P = .04, respectively). Endotoxin activity assay levels after refeeding were similar to baseline levels. Patients with abdominal distension and feeding intolerance showed higher median peak EAA levels (0.7, 0.66-1.11) than asymptomatic patients (0.53, 0.35-0.64; P = .01).

CONCLUSIONS

Endotoxin activity assay levels increase after elective neonatal surgery and are not modified by refeeding. High postoperative levels may predict feeding intolerance.

The digestive tract as the origin of systemic inflammation

Failure of gut homeostasis is an important factor in the pathogenesis and progression of systemic inflammation, which can culminate in multiple organ failure and fatality. Pathogenic events in critically ill patients include mesenteric hypoperfusion, dysregulation of gut motility, and failure of the gut barrier with resultant translocation of luminal substrates. This is followed by the exacerbation of local and systemic immune responses. All these events can contribute to pathogenic crosstalk between the gut, circulating cells, and other organs like the liver, pancreas, and lungs. Here we review recent insights into the identity of the cellular and biochemical players from the gut that have key roles in the pathogenic turn of events in these organ systems that derange the systemic inflammatory homeostasis. In particular, we discuss the dangers from within the gastrointestinal tract, including metabolic products from the liver (bile acids), digestive enzymes produced by the pancreas, and inflammatory components of the mesenteric lymph.

Cascade regulation of PPARγ(2) and C/EBPα signaling pathways by celastrol impairs adipocyte differentiation and stimulates lipolysis in 3T3-L1 adipocytes

OBJECTIVE

Celastrol, a triterpene from the root bark of the Chinese medicinal plant Tripterygium wilfordii, has been shown to exhibit anti-oxidant, anti-inflammatory, anti-cancer and insecticidal activities. Also, it has been demonstrated that celastrol has obesity-controlling effects in diet-induced obesity mice. However, direct evidence that celastrol contributes to the development of adipocyte differentiation and lipolysis has not been fully elucidated. Moreover, no previous studies have evaluated whether celastrol may regulate adipogenic transcriptional markers in adipocytes.

MATERIALS/METHODS

In order to address the questions above, we extended previous observations and investigated in vitro celastrol signaling study whether celastrol may regulate differentiation, lipolysis and key adipogenic transcriptional pathways in 3T3-L1 adipocytes.

RESULTS

Treatment of celastrol not only inhibited adipocyte differentiation (lipid accumulation, glyceraldehyde-3-phosphate dehydrogenase activity and triglyceride content) but also increased lipolysis (glycerol release and free fatty acid release) in 3T3-L1 adipocytes. In addition, all celastrol-regulated functional activities were controlled by PPARγ(2) and C/EBPα signaling pathways in duration of celastrol's treatment in 3T3-L1 adipocytes.

CONCLUSION

Our initial data from in vitro celastrol signaling studies suggest novel insights into the role of PPARγ(2) and C/EBPα as probable mediators of the action of celastrol in regulating adipocyte differentiation and lipolysis in 3T3-L1 adipocytes.

Pharmacokinetics of Posaconazole Oral Suspension in Children Dosed According to Body Surface Area

BACKGROUND

Antifungal prophylaxis remains challenging in immunocompromised children as no clear consensus has yet been reached about which drug to be used. Posaconazole has a broad spectrum of activity, a favorable safety profile and excellent prophylactic activity in adults. However, a lack of pharmacokinetic studies in pediatric patients hampers routine implementation. This study investigates the pharmacokinetics of a newly introduced posaconazole dosing regimen based on the body surface area in pediatric hematologic patients.

METHODS

In this prospective pharmacokinetic study, 8 blood samples were taken during 1 dosing interval at steady state in children aged 13 years or younger with hematologic malignancy, who were treated prophylactically with posaconazole oral suspension at a dose of 120 mg/m 3 times daily. Posaconazole plasma concentrations were determined using high-performance liquid chromatography fluorescence detection.

RESULTS

One hundred twelve samples were taken from 14 patients with a mean age of 6.7 ± 2.8 years. A median posaconazole daily dose of 100.0 mg (77.3-100.0) 3 times daily (tid), corresponding to a median of 117.9 mg/m (112.2-120.4) tid, resulted in mean trough posaconazole plasma concentrations of 0.85 ± 0.56 mg/L. Pharmacokinetic analysis revealed a clearance of 0.8 L/(h kg) (0.5-1.4). No invasive fungal infections or adverse events were encountered during treatment.

CONCLUSIONS

Posaconazole is a promising antifungal agent to be used prophylactically in hematologic patients aged 13 years or younger. Administering posaconazole oral suspension in a dosage of 120 mg/m tid results in adequate posaconazole plasma exposure, without significant adverse events.

Evaluation of Endotoxemia After Pediatric Cardiac Surgery With the Endotoxin Activity Assay: An Exploratory Prospective Cohort Study

OBJECTIVE

Children with congenital heart diseases undergoing surgery with cardiopulmonary bypass are exposed to a high risk of perioperative endotoxemia. The aim of our study was to prospectively evaluate endotoxin assay activity reference levels during the postoperative phase of infants undergoing cardiac surgery for congenital heart disease and to assess their association with perioperative variables and postoperative infections.

DESIGN

Prospective exploratory single-center cohort study.

SETTING

Tertiary pediatric cardiac ICU.

PATIENTS

Infants undergoing cardiac surgery with cardiopulmonary bypass were enrolled. Exclusion criteria were preoperative suspected or confirmed infection, the need for extracorporeal membrane oxygenation or a ventricular assist device in any perioperative phase, surgery for heart transplantation, and/or urgent surgery.

INTERVENTIONS

Serial measurements of endotoxin assay activity were performed at baseline, pediatric cardiac ICU arrival, postoperative day 1 and 2.

MEASUREMENTS AND MAIN RESULTS

Twenty-five patients were enrolled. Overall, 14 of 25 patients (58%) presented at least one endotoxin assay activity level greater than 0.4 during the study period (normal level is < 0.4). Endotoxin assay activity levels tended to significantly increase from baseline to postoperative day 1 and 2 and from pediatric cardiac ICU arrival to postoperative day 2 (p < 0.0001). Endotoxin assay activity greater than 0.6 predicted Gram-negative infections with a sensitivity of 0.40, a specificity of 0.95, a positive predictive value of 0.66, and a negative predictive value of 0.86. At multivariable regression, endotoxin assay activity on postoperative day 1 resulted independently associated with cardiopulmonary bypass duration, lactate, temperature peak, and vasoactive inotropic score at pediatric cardiac ICU arrival. Children with endotoxin assay activity levels greater than 0.6 (vs all the others) showed a significantly higher median (interquartile) number of ventilation days: 8 (2-39) versus 1.5 (1-3 (p = 0.02).

CONCLUSIONS

This exploratory study showed that endotoxin assay activity levels in infants undergoing cardiopulmonary bypass are frequently above 0.4 and peak 24-48 hours after surgery and appear to be associated with perioperative impaired organ perfusion. Endotoxin assay activity is not useful to predict Gram-negative infections.

Nutrition: A Primary Therapy in Pediatric Acute Respiratory Distress Syndrome

Appropriate nutrition is an essential component of intensive care management of children with acute respiratory distress syndrome (ARDS) and is linked to patient outcomes. One out of every two children in the pediatric intensive care unit (PICU) will develop malnutrition or have worsening of baseline malnutrition and present with specific micronutrient deficiencies. Early and adequate enteral nutrition (EN) is associated with improved 60-day survival after pediatric critical illness, and, yet, despite early EN guidelines, critically ill children receive on average only 55% of goal calories by PICU day 10. Inadequate delivery of EN is due to perceived feeding intolerance, reluctance to enterally feed children with hemodynamic instability, and fluid restriction. Underlying each of these factors is large practice variation between providers and across institutions for initiation, advancement, and maintenance of EN. Strategies to improve early initiation and advancement and to maintain delivery of EN are needed to improve morbidity and mortality from pediatric ARDS. Both, over and underfeeding, prolong duration of mechanical ventilation in children and worsen other organ function such that precise calorie goals are needed. The gut is thought to act as a "motor" of organ dysfunction, and emerging data regarding the role of intestinal barrier functions and the intestinal microbiome on organ dysfunction and outcomes of critical illness present exciting opportunities to improve patient outcomes. Nutrition should be considered a primary rather than supportive therapy for pediatric ARDS. Precise nutritional therapies, which are titrated and targeted to preservation of intestinal barrier function, prevention of intestinal dysbiosis, preservation of lean body mass, and blunting of the systemic inflammatory response, offer great potential for improving outcomes of pediatric ARDS. In this review, we examine the current evidence regarding dose, route, and timing of nutrition, current recommendations for provision of nutrition to children with ARDS, and the current literature for immune-modulating diets for pediatric ARDS. We will examine emerging data regarding the role of the intestinal microbiome in modulating the response to critical illness.

The Year in Review

Congenital cardiac anesthesiology is a rapidly expanding field at both ends of the life spectrum. The care of the unborn child with congenital heart disease is becoming highly specialized in regional centers that offer advanced imaging techniques, coordinated specialist care, and potentially fetal interventions. As more children with congenital heart disease survive to adulthood, patients and their health care providers are facing new challenges. The growing volume of publications reflects this expanding field of congenital cardiac anesthesiology. This year in review article highlights some developing trends in the literature.