The 2016 ESPEN Arvid Wretlind lecture: The gut in stress

Evaluation of the protective role of resveratrol on LPS-induced septic intestinal barrier function via TLR4/MyD88/NF-κB signaling pathways

The intestinal barrier function is a critical defense mechanism in the human body, serving as both the primary target and initiating organ in cases of sepsis. Preserving the integrity of this barrier is essential for preventing complications and diseases, including sepsis and mortality. Despite this importance, the impact of resveratrol on intestinal barrier function remains unclear. Thus, this study aims to explore the potential beneficial effects of resveratrol on maintaining intestinal barrier function. Fifteen male Sprague Dawley rats, weighing between 180 g and 220 g, were randomly assigned to one of three groups: the control group (Con), the lipopolysaccharide (LPS) group, and the resveratrol (RSV) group. The resveratrol group received an intravenous administration of resveratrol at a dosage of 8 mg/kg, 10 min prior to lipopolysaccharide treatment. Each group comprised five rats. Various techniques including enzyme-linked immunosorbent assay (ELISA), hematoxylin and eosin staining (HE), periodic acid Schiff (PAS) staining, transmission electron microscopy (TEM), Western blot analysis (WB), and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized to assess differences in inflammatory cytokine expression, histopathological changes, apoptosis, tight junction (TJ) protein, and the TLR4/MyD88/NF-кB signaling pathways. Resveratrol exhibited anti-inflammatory effects by decreasing levels of interleukin (IL)-1β, interleukin(IL)-6, and tumor necrosis factor (TNF)-α, while increasing interleukin (IL)-10. Additionally, in rats treated with resveratrol, there was a reduction in the expression of apoptosis-associated proteins Bax and Caspase-3. Resveratrol also significantly increased the expression of intestinal tight junction proteins (TJ), and decreased the levels of intestinal fatty acid binding protein (I-FABP) and D-lactic acid (D-LA). Furthermore, the expression of proteins in the related signaling pathways TLR4, MyD88, and NF-κB was decreased. Resveratrol has been shown to reduce the expression of intestinal apoptotic proteins, enhance the expression of intestinal tight junction proteins, and inhibit the inflammatory response mediated by the TLR4/MyD88/NF-κB signaling pathway, thereby alleviating LPS-induced septic intestinal injury.

Nutritional Support in the ICU

Critical illness is a complex condition that can have a devastating impact on health and quality of life. Nutritional support is a crucial component of critical care that aims to maintain or restore nutritional status and muscle function. A one-size-fits-all approach to the components of nutritional support has not proven beneficial. Recent randomized controlled trials challenge the conventional strategy and support the safety and potential benefits of below-usual calorie and protein intakes at the early, acute phase of critical illness. Further research is needed to define optimal nutritional support throughout the intensive care unit stay. Individualized nutritional strategies relying on risk assessment tools or biomarkers deserve further investigation in rigorously designed, large, multicenter, randomized, controlled trials. Importantly, although nutritional support is crucial, it might not be sufficient to enhance the recovery of critically ill patients. Thus, achieving the greatest efficacy may require individualized nutritional support combined with early, prolonged physical rehabilitation within a multimodal, holistic care program throughout the patient's recovery journey.

Higher caloric intake through enteral nutrition is associated with lower hospital mortality rates in patients with candidemia and shock in Taiwan

BACKGROUND

Candidemia is associated with markedly high intensive care unit (ICU) mortality rates. Although the Impact of Early Enteral vs. Parenteral Nutrition on Mortality in Patients Requiring Mechanical Ventilation and Catecholamines (NUTRIREA-2) trial indicated that early enteral nutrition (EN) did not reduce 28-day mortality rates among critically ill patients with shock, the European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines recommend avoiding EN in cases of uncontrolled shock. Whether increased caloric intake from EN positively impacts clinical outcomes in patients with candidemia and shock remains unclear.

METHODS

We retrospectively collected data from a tertiary medical center between January 2015 and December 2018. We enrolled patients who developed shock within the first 7 days following ICU admission and received a diagnosis of candidemia during their ICU stay. Patients with an ICU stay shorter than 48 hours were excluded.

RESULTS

The study included 106 patients, among whom the hospital mortality rate was 77.4% (82 patients). The median age of the patients was 71 years, and the median Acute Physiology and Chronic Health Evaluation II score was 29. The Cox regression model revealed that a higher 7-day average caloric intake through EN (hazard ratio, 0.61; 95% CI, 0.44-0.83) was significantly associated with lower hospital mortality rates. Our findings suggest EN as the preferred feeding route for critically ill patients with shock.

CONCLUSIONS

Increased caloric intake through EN may be associated with lower hospital mortality rates in patients with candidemia and shock.

"Feed a Cold, Starve a Fever?" A Review of Nutritional Strategies in the Setting of Bacterial Versus Viral Infections

PURPOSE OF REVIEW

Some data, mostly originally derived from animal studies, suggest that low glucose intake is protective in bacterial sepsis but detrimental in overwhelming viral infections. This has been interpreted into a broad belief that different forms of sepsis may potentially require different nutritional management strategies. There are a few mechanistic differences between the host interactions with virus and bacteria which can explain why there may be opposing responses to macronutrient and micronutrient during the infected state. Here, we aim to review relevant evidence on the mechanisms and pathophysiology of nutritional management strategies in various infectious syndromes and summarize their clinical implications.

RECENT FINDINGS

Newer literature - in the context of the SARS-CoV-19 pandemic - offers some insight to viral infections. There is still limited clinically applicable data during infection that clearly delineate the role of nutrition during an active viral vs bacterial infections. Based on contrasting findings in different models of viruses and bacteria, the macronutrient and micronutrient needs may depend more on specific infectious organisms that may not be generalizable as bacterial versus viral. Overall, the metabolic effects of sepsis are context dependent, and various host-specific (e.g., age, baseline nutritional status, immune status, comorbidities) and illness variables (phase, duration, and severity of illness) play a significant role in determining the outcome besides pathogen-specific (virus or bacterial or fungi and combined infections) factors. Microbe therapy (probiotics and prebiotics) seems to have therapeutic potential in both viral and bacterial infected states, and this seems like a promising area for further practical research.

Trophic Nutrition in ICU Patients Undergoing High-Flow Oxygen Therapy and/or Noninvasive Mechanical Ventilation: The Nutri-Trophic Study

Enteral nutrition (EN) therapy in ICU patients requiring oxygen therapy with high-flow nasal cannula (HFNC) and/or noninvasive mechanical ventilation (NIMV) is controversial. A prospective, cohort, observational, and multicenter study was conducted in 10 ICUs in Spain to analyze the 90-day mortality, tolerance, side effects, and infectious complications of trophic EN in patients requiring HFNC therapy and/or NIVM. A total of 149 patients were enrolled. The mean age, severity scores, tracheobronchitis, bacteremia, and antimicrobial therapy were significantly higher in deceased than in living patients (p < 0.05), and the mortality rate was 14.8%. A total of 110 patients received oral trophic feedings, 36 patients received nasogastric tube feedings (NGFs), and 3 received mixed feedings. Trophic EN was discontinued in only ten (14.9%) patients because of feeding-related complications. The variables selected for the multivariate logistic regression on feeding discontinuation were SOFA upon admission (OR per unit = 1.461) and urea (OR per mg/dL = 1.029). There were no significant differences in the development of new infections according to the route of EN administration. Early trophic feeding administered to patients with acute respiratory failure requiring noninvasive ventilation is safe and feasible, and is associated with few dietary and infectious complications in a mortality, setting comparable to similar studies.

Smartfeeding: A Dynamic Strategy to Increase Nutritional Efficiency in Critically Ill Patients-Positioning Document of the Metabolism and Nutrition Working Group and the Early Mobilization Working Group of the Catalan Society of Intensive and Critical Care Medicine (SOCMiC)

Adequate medical nutrition therapy for critically ill patients has an impact on their prognoses. However, it requires an individualized approach that takes into account the activity (phases of metabolic stress) and particularity of these patients. We propose a comprehensive strategy considering the patients' nutritional status and the set of modifiable circumstances in these patients, in order to optimize/support nutritional efficiency: (1) A detailed anamnesis and an adequate initial nutritional assessment must be performed in order to implement medical nutrition therapy that is in line with the needs and characteristics of each patient. Furthermore, risks associated with refeeding syndrome, nutritrauma or gastrointestinal dysfunction must be considered and prevented. (2) A safe transition between nutrition therapy routes and between health care units will greatly contribute to recovery. The main objective is to preserve lean mass in critically ill patients, considering metabolic factors, adequate protein intake and muscle stimulation. (3) Continuous monitoring is required for the successful implementation of any health strategy. We lack precise tools for calculating nutritional efficiency in critically ill patients, therefore thorough monitoring of the process is essential. (4) The medical nutrition approach in critically ill patients is multidisciplinary and requires the participation of the entire team involved. A comprehensive strategy such as this can make a significant difference in the functional recovery of critically ill patients, but leaders must be identified to promote training, evaluation, analysis and feedback as essential components of its implementation, and to coordinate this process with the recognition of hospital management.

Risk Factors of Enternal Nutrition Intolerance in Septic Patients: A Case-control Study

OBJECTIVE

This study aimed to investigate the incidence of enteral nutrition intolerance (ENI) in patients with sepsis and explore potential risk factors.

METHODS

A case-control study was conducted in patients with sepsis who were receiving enteral nutrition (EN) at a tertiary hospital in China. The included patients were divided into the ENI group and the non-ENI group. Univariate and multivariate analyses were performed to identify the risk factors for ENI.

RESULTS

A total of 859 patients were included in the study. Among them, 288 (33.53%) patients experienced symptoms of ENI, including diarrhea, vomiting, bloating, and gastric retention. Logistic regression analysis revealed that the Acute Physiology and Chronic Health Evaluation H (APACHE H) score, thoracocentesis, and usage of cardiotonic drugs (namely, inotropes) were independent predictors of the ENI.

CONCLUSION

The incidence of ENI is relatively high in patients with sepsis, especially in those who have higher APACHE H scores, have undergone thoracocentesis, and have received inotropes.

EUS-Guided Gallbladder Drainage Using a Lumen-Apposing Metal Stent for Acute Cholecystitis: Results of a Nationwide Study with Long-Term Follow-Up

BACKGROUND

Although endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using lumen-apposing metal stents (LAMS) has become one of the treatments of choice for acute cholecystitis (AC) in fragile patients, scant data are available on real-life settings and long-term outcomes.

METHODS

We performed a multicenter retrospective study including EUS-guided GBD using LAMS for AC in 19 Italian centers from June 2014 to July 2020. The primary outcomes were technical and clinical success, and the secondary outcomes were the rate of adverse events (AE) and long-term follow-up.

RESULTS

In total, 116 patients (48.3% female) were included, with a mean age of 82.7 ± 11 years. LAMS were placed, transgastric in 44.8% of cases, transduodenal in 53.3% and transjejunal in 1.7%, in patients with altered anatomy. Technical success was achieved in 94% and clinical success in 87.1% of cases. The mean follow-up was 309 days. AEs occurred in 12/116 pts (10.3%); 8/12 were intraprocedural, while 1 was classified as early (<15 days) and 3 as delayed (>15 days). According to the ASGE lexicon, two (16.7%) were mild, three (25%) were moderate, and seven (58.3%) were severe. No fatal AEs occurred. In subgroup analysis of 40 patients with a follow-up longer than one year, no recurrence of AC was observed.

CONCLUSIONS

EUS-GBD had high technical and clinical success rates, despite the non-negligible rate of AEs, thus representing an effective treatment option for fragile patients.

The human gut microbiome in critical illness: disruptions, consequences, and therapeutic frontiers

With approximately 39 trillion cells and over 20 million genes, the human gut microbiome plays an integral role in both health and disease. Modern living has brought a widespread use of processed food and beverages, antimicrobial and immunomodulatory drugs, and invasive procedures, all of which profoundly disrupt the delicate homeostasis between the host and its microbiome. Of particular interest is the human gut microbiome, which is progressively being recognized as an important contributing factor in many aspects of critical illness, from predisposition to recovery. Herein, we describe the current understanding of the adverse impacts of standard intensive care interventions on the human gut microbiome and delve into how these microbial alterations can influence patient outcomes. Additionally, we explore the potential association between the gut microbiome and post-intensive care syndrome, shedding light on a previously underappreciated avenue that may enhance patient recuperation following critical illness. There is an impending need for future epidemiological studies to encompass detailed phenotypic analyses of gut microbiome perturbations. Interventions aimed at restoring the gut microbiome represent a promising therapeutic frontier in the quest to prevent and treat critical illnesses.

Personalized nutrition therapy in critical care: 10 expert recommendations

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

Early enteral versus early parenteral nutrition in critically ill patients with respiratory distress: a case–control study

Background

Nutritional support is essential as enteral or parenteral nutrition to reduce catabolism, to lower the complications rate, and to improve outcomes in critically ill patients.

Results

The median, range age of the cohort was (median 10, range 6–18.8 months). One-hundred thirteen (62.8%) were males, and 67 (37.2%) were females. The higher frequency of sepsis, ventilator-acquired pneumonia (VAP), and mortality founded in the group received PN. Frequency of sepsis was 15 (16.7%), VAP was 5 (5.6%), and the mortality rate was 11.1% in EN group, while frequency of sepsis was 37 (41.1%), VAP was 23 (25.6%), and the mortality rate was 27.8% in PN group (P = 0.001, 0.001, 0.01, respectively). Median of weight gain on the EN group was 0.17 kg at 2nd week which was more than those in PN group (P = 0.001). The mean ± SD time for reaching the caloric target for those receiving early EN was 4.0 ± 1.9 days which is earlier than that of PN group (6.2 ± 1.7 days) (P = 0.001). There is no significant difference between both groups as regard pediatric intensive care unit (PICU) stay length and mechanical ventilation stay length.

Conclusion

Early EN remains the preferred route for nutrient delivery as the PN route was accompanied by a lot of complication such as sepsis, VAP, and high mortality rate.

Elderly Patients and Management in Intensive Care Units (ICU): Clinical Challenges

There is a growing population of older adults requiring admission to the intensive care unit (ICU). This population outpaces the ability of clinicians with geriatric training to assist in their management. Specific training and education for intensivists in the care of older patients is valuable to help understand and inform clinical care, as physiologic changes of aging affect each organ system. This review highlights some of these aging processes and discusses clinical implications in the vulnerable older population. Other considerations when caring for these older patients in the ICU include functional outcomes and morbidity, as opposed to merely a focus on mortality. An overall holistic approach incorporating physiology of aging, applying current evidence, and including the patient and their family in care should be used when caring for older adults in the ICU.

Preparative Fasting Orders for Medical/Surgical Interventions and Imaging Studies: Time to Review and Revise!

PURPOSE OF THE REVIEW

Preparative fasting orders arose out of a purported need to enhance imaging studies, reduce interference of food with intended medical/surgical interventions, and protect the patient from vomiting and aspiration pneumonia. This review discusses the frequency, appropriateness, and efficacy of fasting orders in meeting those needs and whether their use should be modified in the future.

RECENT FINDINGS

Nil per os (NPO) orders are overused, as they are often inappropriate, typically excessive, and routinely create barriers which may increase risk for patients. Fasting orders are used more often for medical procedures than for surgical operations or imaging studies. One fourth of NPO orders are inappropriate, and the intended procedure or study is canceled 20% of the time usually for a change in plans or scheduling error and rarely because of patient eating. Nausea/vomiting associated with contrast media or imaging studies is rare, self-limited, and not linked to preparatory fluid or food ingestion. Prolonged fasting reduces patient cooperation and satisfaction, and may contribute to a higher rate of complications. Each institution should review and revise preparative fasting orders. Drinking of fluids should be allowed without restriction. Truncated periods of solid food restriction may be required due to technical reasons related to specific imaging studies, and for procedures or surgical operations which require sedation or general anesthesia. Inappropriate and prolonged fasting should be avoided, as they create barriers to adequate nutritional therapy and impose added risk with regard to patient outcomes.

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

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

Early Enteral Nutrition Tolerance in Patients With Cardiogenic Shock Requiring Mechanical Circulatory Support

Background: Enteral nutrition (EN) is recommended within the first 24-48 h for patients with hemodynamic stability, following admission to an intensive care unit (ICU). However, for patients with approximate stable hemodynamics requiring mechanical circulatory support and vasoactive drugs, the application of early EN remains controversial. We sought to evaluate the tolerance of early EN in patients with cardiogenic shock who required vasoactive drugs and mechanical circulatory support after cardiac surgery. Methods: This single-center, prospective observational study included patients with cardiogenic shock, requiring vasoactive drugs and mechanical circulatory support after cardiac surgery, undergoing EN. The primary endpoint was EN tolerance and secondary endpoints were mortality, length of mechanical ventilation, and length of ICU stay. Results: From February 2019 to December 2020, 59 patients were enrolled, of which 25 (42.37%) developed intolerance within 3 days of starting EN. Patients in the EN intolerant group had a longer median length of mechanical ventilation (380 vs. 128 h, p = 0.006), a longer median ICU stay (20 vs. 11.5 days, p = 0.03), and a higher proportion of bloodstream infections (44 vs. 14.71%, p = 0.018). The median EN calorie levels for all patients in the first 3 days of EN were 4.00, 4.13, and 4.28 kcal/kg/day, respectively. Median protein intake levels of EN in the first 3 days were 0.18, 0.17, and 0.17 g/kg/day, respectively. No significant difference was observed in the median dose of vasoactive drugs between the groups (0.035 vs. 0.05 μg/kg/min, p = 0.306). Conclusions: Patients with cardiogenic shock after cardiac surgery had a high proportion of early EN intolerance, and patients with EN intolerance had a worse prognosis, but no significant correlation was identified between EN tolerance and the dose of vasoactive drugs.

Fecal Microbial Transplantation in Critically Ill Patients-Structured Review and Perspectives

The human gut microbiota consists of bacteria, archaea, fungi, and viruses. It is a dynamic ecosystem shaped by several factors that play an essential role in both healthy and diseased states of humans. A disturbance of the gut microbiota, also termed "dysbiosis", is associated with increased host susceptibility to a range of diseases. Because of splanchnic ischemia, exposure to antibiotics, and/or the underlying disease, critically ill patients loose 90% of the commensal organisms in their gut within hours after the insult. This is followed by a rapid overgrowth of potentially pathogenic and pro-inflammatory bacteria that alter metabolic, immune, and even neurocognitive functions and that turn the gut into the driver of systemic inflammation and multiorgan failure. Indeed, restoring healthy microbiota by means of fecal microbiota transplantation (FMT) in the critically ill is an attractive and plausible concept in intensive care. Nonetheless, available data from controlled studies are limited to probiotics and FMT for severe C. difficile infection or severe inflammatory bowel disease. Case series and observational trials have generated hypotheses that FMT might be feasible and safe in immunocompromised patients, refractory sepsis, or severe antibiotic-associated diarrhea in ICU. There is a burning need to test these hypotheses in randomized controlled trials powered for the determination of patient-centered outcomes.

Interplay between Gut Lymphatic Vessels and Microbiota

Lymphatic vessels play a distinctive role in draining fluid, molecules and even cells from interstitial and serosal spaces back to the blood circulation. Lymph vessels of the gut, and especially those located in the villi (called lacteals), not only serve this primary function, but are also responsible for the transport of lipid moieties absorbed by the intestinal mucosa and serve as a second line of defence against possible bacterial infections. Here, we briefly review the current knowledge of the general mechanisms allowing lymph drainage and propulsion and will focus on the most recent findings on the mutual relationship between lacteals and intestinal microbiota.

Can feeding strategies alter immune signaling and gut sepsis in critical illness?

The insult necessitating admission to the intensive care unit propels the patient along a course involving increasing oxidative stress, immune dysregulation, and adverse outcomes. As the largest immune organ with the greatest microbial burden, the gastrointestinal tract may change the speed and direction the patient follows along this pathway. The gut's influence is mediated by a complex process of cross-talk immune signaling between the intestinal epithelium, the liver, and the microbiome. Agents which invoke this response vary from mitochondrial DNA, inflammatory cytokines, and bacterial organisms to short chain fatty acids and bile salts. The site of action of these agents again varies widely from Pattern Recognition Receptors, G protein receptors, and Farnesoid X receptors in the gut and liver to transcriptional factors in epithelial cells, hepatocytes, macrophages, and neutrophils. While the initial focus of response may be local within the gastrointestinal tract and liver, the process extends in a systemic manner to affect immune tissue and various organs at distant sites. The gut can modulate this cross-talk signaling through numerous strategies in design of nutritional therapy. The physiologic response to luminal nutrients and short chain fatty acids, and more novel approaches like use phosphorylated polyethylene glycol, bovine serum-derived immunoglobulin, and specialized pro-resolving molecules may help slow disease progression and even reverse the patient's course toward one of health and recovery. The optimal benefit to be derived from nutritional therapy may have more to do with the degree to which immune cross-talk signaling can be modified by such innovative strategies. This article is protected by copyright. All rights reserved.

Efficacy and safety of early oral feeding in postoperative patients with upper gastrointestinal tumor: A systematic review and meta-analysis

BACKGROUND

Early oral feeding (EOF) is an important measure for early recovery of patients with gastrointestinal tumors after surgery, which has emerged as a safe and effective postoperative strategy for improving clinical outcomes.

AIM

To determine the safety and efficacy of early oral feeding in postoperative patients with upper gastrointestinal tumor.

METHODS

This meta-analysis was analyzed using Review Manager version 5.3 and Stata version 14. All clinical studies that analyzed efficacy and safety of EOF for postoperative patients with upper gastrointestinal tumor were included.

RESULTS

Fifteen studies comprising 2100 adult patients met all the inclusion criteria. A significantly lower risk of pneumonia was presented in the EOF compared with TOF group [relative risk (RR) = 0.63, 95% confidence interval (CI): 0.44–0.89, P = 0.01]. Length of hospital stay was significantly shorter in the EOF group than in the TOF group [weighted mean difference (WMD) = -1.91, 95%CI: -2.42 to -1.40; P < 0.01]. Cost of hospitalization was significantly lower (WMD = -4.16, 95%CI: -5.72 to -2.61; P < 0.01), and CD4 cell count and CD4/CD8 cell ratio on postoperative day 7 were significantly higher in the EOF group than in the TOF group: CD4 count (WMD = 7.17, 95%CI: 6.48–7.85; P < 0.01), CD4/CD8 ratio (WMD = 0.29, 95%CI: 0.23–0.35; P < 0.01). There was no significant difference in risk of anastomotic leak and total postoperative complications.

CONCLUSION

EOF as compared with TOF was associated with lower risk of pneumonia, shorter hospital length of stay, lower cost of hospitalization, and significantly improved postoperative immune function of patients.

IBDs and the pediatric age: Their peculiarities and the involvement of the microbiota

Inflammatory Bowel Diseases (IBDs) are gastrointestinal disorders characterized by chronic, relapsing inflammation, with growing incidence worldwide over the last decades and distinctive features in the pediatric age. An increasing body of evidence indicates that gut microbiota plays a major role in inflammatory disorders, including IBDs. In this review we will discuss the most recent evidences on dysbiotic changes associated with gut inflammation, as well as environmental and genetic factors contributing to IBD pathogenesis, with a focus on the peculiarities of the pediatric age.

Relevant Nutrition Therapy in COVID-19 and the Constraints on Its Delivery by a Unique Disease Process

Worldwide, as of July 2020, >13.2 million people have been infected by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The spectrum of coronavirus disease 2019 (COVID-19) ranges from mild illness to critical illness in 5% of cases. The population infected with SARS-CoV-2 requiring an intensive care unit admission often requires nutrition therapy as part of supportive care. Although the various societal guidelines for critical care nutrition meet most needs for the patient with COVID-19, numerous factors, which impact the application of those guideline recommendations, need to be considered. Since the SARS-CoV-2 virus is highly contagious, several key principles should be considered when caring for all patients with COVID-19 to ensure the safety of all healthcare personnel involved. Management strategies should cluster care, making all attempts to bundle patient care to limit exposure. Healthcare providers should be protected, and the spread of SARS-CoV-2 should be limited by minimizing procedures and other interventions that lead to aerosolization, avoiding droplet exposure through hand hygiene and use of personal protective equipment (PPE). PPE should be preserved by decreasing the number of individuals providing direct patient care and by limiting the number of patient interactions. Enteral nutrition (EN) is tolerated by the majority of patients with COVID-19, but a relatively low threshold for conversion to parenteral nutrition should be maintained if increased exposure to the virus is required to continue EN. This article offers relevant and practical recommendations on how to optimize nutrition therapy in critically ill patients with COVID-19.

Mitochondrial Dysfunction in Critical Illness: Implications for Nutritional Therapy

PURPOSE OF THE REVIEW

This paper will review the evidence for mitochondrial dysfunction in critical illness, describe the mechanisms which lead to multiple organ failure, and detail the implications of this pathophysiologic process on nutritional therapy.

RECENT FINDINGS

Mitochondria are particularly sensitive to increased oxidative stress in critical illness. The functional and structural abnormalities which occur in this organelle contribute further to the excessive production of reactive oxygen species and the reduction in generation of adenosine triphosphate (ATP). To reduce metabolic demand, mitochondrial dysfunction develops (a process likened to hibernation), which helps sustain the life of the cell at a cost of organ system failure. Aggressive feeding in the early phases of critical illness might inappropriately increase demand at a time when ATP production is limited, further jeopardizing cell survival and potentiating the processes leading to multiple organ failure. Several potential therapies exist which would promote mitochondrial function in the intensive care setting through support of autophagy, antioxidant defense systems, and the biogenesis and recovery of the organelle itself. Nutritional therapy should supplement micronutrients required in the mitochondrial metabolic pathways and provide reduced delivery of macronutrients through slower advancement of feeding in the early phases of critical illness. A better understanding of mitochondrial dysfunction in the critically ill patient should lead to more innovative therapies in the future.

Microbiome: what intensivists should know

The standard conditions of critical illness (including sepsis, acute respiratory distress syndrome, and multiorgan failure) cause enormous global mortality and a growing economic burden. Increasing evidence suggests that critical illness may be associated with loss of commensal microbes and overgrowth of potentially pathogenic and inflammatory bacteria. This state could be associated with poor outcomes. Therefore, microbiota-targeted interventions are potentially attractive novel treatment options. Although the precise mechanisms of microbiome-directed treatments such as prebiotics, probiotics, and fecal microbiota transplantation remain to be determined, they can be utilized in the Intensive Care Unit (ICU) setting. The current review aims to offer intensivists an evidenced-based approach on what we currently know about the role of the microbiome in critical illness and how the microbiome could be targeted in the clinical practice to improve ICU-related outcomes.

Clinical nutrition for the gastroenterologist: bedside strategies for feeding the hospitalized patient

PURPOSE OF REVIEW

The timing, advancement, and use of appropriate monitors determine whether the hospitalized patient experiences the full benefit of nutritional therapy. This article reviews management strategies in delivering the optimal nutrition regimen capable of improving outcomes in the hospitalized patient.

RECENT FINDINGS

Enteral nutrition should be initiated in the first 24-36 h after admission. Determination of nutritional risk helps guide the urgency with which nutritional therapy is provided and predicts the likelihood for difficulties in delivering the prescribed regimen. Feeds should be advanced slowly over 3-4 days to meet 70-80% of goal for calories (20 kcal/kg/day) and 100% for protein (2.0 gm/kg/day). Reaching protein goals early on may be more important than achieving energy goals. Patients should be monitored for hemodynamic stability, evidence of refeeding syndrome, and tolerance in the setting of gastrointestinal dysfunction. Parenteral nutrition should be utilized in select high-risk patients where the feasibility of full enteral nutrition is questioned.

SUMMARY

Timing with early initiation of enteral nutrition, avoidance of overfeeding, and step-wise advancement of feeds are required to safely realize the benefits of such therapy.

Clinical nutrition for the gastroenterologist: the physiologic rationale for providing early nutritional therapy to the hospitalized patient

PURPOSE OF REVIEW

Conflicting reports in the literature have been misinterpreted by clinicians, who conclude that nutritional therapy for the hospitalized patient is of marginal value. The true benefit of such therapy is derived from the provision of early enteral nutrition. This article describes the physiologic response to enteral feeding, which accounts for the outcome benefits, and illustrates how use of the gut alters immune responses and the intestinal microbiota.

RECENT FINDINGS

The provision of early enteral nutrition has been shown to reduce infection and mortality in high-risk hospitalized patients (compared with not providing such therapy). Early feeding maintains gut integrity, reduces permeability, promotes tolerance and appropriate immune responses, and supports commensalism of the intestinal microbiota. Early enteral nutrition influences cross-talk signaling between luminal bacteria and the intestinal epithelium. Failure to utilize the gut in acute illness can amplify the systemic inflammatory response syndrome and worsen disease severity, while at the same time promoting antibiotic resistance and increased septic morbidity.

SUMMARY

Appropriate nutritional therapy does change outcomes in the hospitalized patient, especially for those who are at risk on the basis of disease severity and/or poor nutritional status. Greatest benefit is seen from those therapeutic regimens that specifically target gut defenses and the intestinal microbiome.

Nutritional support in the recovery phase of critically ill children

PURPOSE OF REVIEW

The metabolic stress response of a critically ill child evolves over time and thus it seems reasonable that nutritional requirements change during their course of illness as well. This review proposes strategies and considerations for nutritional support during the recovery phase to gain optimal (catch-up) growth with preservation of lean body mass.

RECENT FINDINGS

Critical illness impairs nutritional status, muscle mass and function, and neurocognition, but early and high intakes of artificial nutrition during the acute phase cannot resolve this. Although (parenteral) nutrient restriction during the acute phase appears to be beneficial, persistent nutrient restriction, when the metabolic stress response resolves, has short-term and long-term detrimental consequences. Requirements increase markedly during the recovery phase to enable recovery and catch-up growth. Such large amounts of intake demand for alternate approach, especially when intestinal problems constitute a barrier for full enteral feeding. As part of the nutritional recovery, mobilization and exercise are essential to achieve catch-up growth with an optimal body composition.

SUMMARY

During the recovery phase of paediatric critical illness (catch-up) growth and muscle recovery require nutritional intakes at least two times the resting energy expenditure.

Gut function in the intensive care unit - What is 'normal'?

BACKGROUND

Management of gut function in the intensive care unit (ICU) is often protocol-driven. Protocols for enteral feeding or bowel management are based on assumptions about what is 'normal' gastrointestinal motility during critical illness or in the early postoperative period, although 'normal' has not been well described in this group.

OBJECTIVES

This study aimed to describe aspects of gut function based on an audit of current ICU patients.

METHODS

A retrospective medical audit of 100 recent consecutive ICU patients was conducted to obtain data on gut function parameters in the critically ill or postoperative population.

RESULTS

The audit indicated that delayed gastric emptying is common in the ICU. Regardless of the definition volume used, large gastric aspirates occurred in most enterally fed patients. Patient positioning was a significant influence, with a bed angle <30° associated with increased gastric aspirates (p = 0.0002). Constipation was more common among enterally fed patients than among orally fed ones (p = 0.001) and was associated with opioids (p = 0.009). Diarrhoea was associated with antibiotic use (p = 0.047). For enterally fed patients, the first bowel motion in the ICU occurred on average day 4.60 (standard deviation, 2.78), compared to day 2.72 (standard deviation, 1.67) for orally fed patients (p = 0.0001).

CONCLUSION

Alteration of upper and lower gastrointestinal motility is common in critically ill and early postoperative patients. Care should be taken in interpreting protocols that relate to gut function to avoid unnecessary interventions or interruptions to nutritional therapy.

Intestinal hyperpermeability: a gateway to multi-organ failure?

In critically ill patients, disruption of intestinal epithelial cell function occurs due to exposure of the epithelium to toxic internal and external inflammatory stimuli, which are key factors that trigger sepsis and multi-organ dysfunction syndrome (MODS). A greater understanding of how trauma and gut failure lead to sepsis and progression to MODS is much needed. In this issue of the JCI, Armacki and colleagues identify mechanisms by which thirty-eight-negative kinase 1 (TNK1) promotes the progression from intestinal apoptosis and gut failure to bacterial translocation, sepsis, and MODS. Moreover, the results of this study suggest TNK1 as a potential therapeutic target to prevent sepsis and MODS.