Early enteral administration of a formula (Impact) supplemented with arginine, nucleotides, and fish oil in intensive care unit patients: results of a multicenter, prospective, randomized, clinical trial

Burn Patient Metabolism and Nutrition

Following severe burns, patients have unique metabolic derangements that make adequate nutritional support imperative for their survival and recovery. Patients with burns have persistent and prolonged hypermetabolic states that lead to increased catabolism following injury. During rehabilitation, catabolism leads to increased muscle wasting and cachexia. Failure to adequately meet the patient's increased nutritional requirements can lead to poor wound healing, increased infections, and overall organ dysfunction. Because of these risks, adequate assessment and provision of nutritional needs are imperative to care for these patients.

Amino acid metabolism in health and disease

Amino acids are the building blocks of protein synthesis. They are structural elements and energy sources of cells necessary for normal cell growth, differentiation and function. Amino acid metabolism disorders have been linked with a number of pathological conditions, including metabolic diseases, cardiovascular diseases, immune diseases, and cancer. In the case of tumors, alterations in amino acid metabolism can be used not only as clinical indicators of cancer progression but also as therapeutic strategies. Since the growth and development of tumors depend on the intake of foreign amino acids, more and more studies have targeted the metabolism of tumor-related amino acids to selectively kill tumor cells. Furthermore, immune-related studies have confirmed that amino acid metabolism regulates the function of effector T cells and regulatory T cells, affecting the function of immune cells. Therefore, studying amino acid metabolism associated with disease and identifying targets in amino acid metabolic pathways may be helpful for disease treatment. This article mainly focuses on the research of amino acid metabolism in tumor-oriented diseases, and reviews the research and clinical research progress of metabolic diseases, cardiovascular diseases and immune-related diseases related to amino acid metabolism, in order to provide theoretical basis for targeted therapy of amino acid metabolism.

Immunonutrition vs standard nutrition for patients with cancer

The prevailing belief in the value of immunonnutrition has been questioned as different patient populations show variable responses ranging from no benefit or even harm to significant improvements in clinical outcomes. The subject of this invited review is a previously published meta-analysis that showed important benefits from the perioperative use of an immunonutrition formula (defined as nutrition therapy that contains specific immune-modulating agents) in a distinct population: adult patients with cancer undergoing an elective major surgical operation. Findings showed that use of an immunonutrition formula was associated with reduced infectious morbidity, anastomotic leakage, hospital length of stay, and postoperative complications compared with standard formulations. These benefits were seen after adjusting for bias and removal of older publications. Issues, such as dosing, duration of therapy, baseline nutrition status, content of specific immunomodulatory agents, and route of delivery that contributed to the beneficial response, were discussed. Little difference in response was seen between well-nourished and malnourished patients, but geographic differences were seen, with greater outcome benefits seen in studies originating from Europe than from Asia or the United States. The best results were seen when at least three agents (arginine, fish oil, and RNA nucleotides) were given, with the timing of the delivery occurring throughout the perioperative period. A review of this meta-analysis is warranted because it shows a consistent benefit from such therapy over 30 years of clinical research, provides a detailed subset analysis of related issues, and highlights its value in improving outcome in this patient population.

Targeted Arginine Metabolism Therapy: A Dilemma in Glioma Treatment

Efforts in the treatment of glioma which is the most common primary malignant tumor of the central nervous system, have not shown satisfactory results despite a comprehensive treatment model that combines various treatment methods, including immunotherapy. Cellular metabolism is a determinant of the viability and function of cancer cells as well as immune cells, and the interplay of immune regulation and metabolic reprogramming in tumors has become an active area of research in recent years. From the perspective of metabolism and immunity in the glioma microenvironment, we elaborated on arginine metabolic reprogramming in glioma cells, which leads to a decrease in arginine levels in the tumor microenvironment. Reduced arginine availability significantly inhibits the proliferation, activation, and function of T cells, thereby promoting the establishment of an immunosuppressive microenvironment. Therefore, replenishment of arginine levels to enhance the anti-tumor activity of T cells is a promising strategy for the treatment of glioma. However, due to the lack of expression of argininosuccinate synthase, gliomas are unable to synthesize arginine; thus, they are highly dependent on the availability of arginine in the extracellular environment. This metabolic weakness of glioma has been utilized by researchers to develop arginine deprivation therapy, which ‘starves’ tumor cells by consuming large amounts of arginine in circulation. Although it has shown good results, this treatment modality that targets arginine metabolism in glioma is controversial. Exploiting a suitable strategy that can not only enhance the antitumor immune response, but also “starve” tumor cells by regulating arginine metabolism to cure glioma will be promising.

Nutrition Management in Patients With Traumatic Brain Injury: A Narrative Review

Traumatic brain injury (TBI) is a major cause of long-term physical and psychological disability and death. In patients with TBI, undernutrition is associated with an increased mortality rate, more infectious complications, and worse neurologic outcomes. Therefore, timely and effective nutritional therapy is particularly crucial in the management of TBI to improve patients' prognoses. This narrative review summarizes the issues encountered in clinical practice for patients with neurotrauma who receive acute and post-acute in-patient rehabilitation services, and it comprehensively incorporates a wide range of studies, including recent clinical practice guidelines (CPGs), with the aim of better understanding the current evidence for optimal nutritional therapy focused on TBI patients. Recent CPGs were reviewed for 6 topics: 1) hypermetabolism and variation in energy expenditure in patients with TBI, 2) delayed gastric emptying and intolerance to enteral nutrition, 3) decision-making on the route and timing of access in patients with TBI who are unable to maintain volitional intake (enteral nutrition versus parenteral nutrition), 4) decision-making on the enteral formula (standard or immune-modulating formulas), 5) glycemic control, and 6) protein support. We also identified areas that need further research in the future.

Nutrition and cutaneous wound healing

Wound healing is a complex and energy-demanding process. The relationship between nutrition and wound healing has been recognized for many centuries. Several studies have indicated that nutritional deficiencies are more prevalent among patients with chronic wounds. Malnutrition may alter the inflammatory response, collagen synthesis, and wound tensile strength, all of which are crucial for wound healing. Although the specific role of nutrition and supplementation in wound care remains uncertain, it is necessary to identify and correct nutritional imbalances to avoid any potential deterioration of the healing process. It is also important to recognize the differences in pathophysiology between acute and chronic wounds. A burn, surgical, or a traumatic wound is different from a diabetic foot ulcer, which is different from a pressure ulcer. Chronic wounds are more prevalent in the aging population, and patients often have underlying comorbidities, such as diabetes mellitus, peripheral vascular disease, connective tissue disease, or other systemic illnesses that may alter energy metabolism and contribute to impaired healing. Management approaches to acute wound care may not apply universally to chronic wounds. In this review, we discuss the available data and possible roles for nutrition in wound healing.

Arginine-dependent immune responses

A growing body of evidence indicates that, over the course of evolution of the immune system, arginine has been selected as a node for the regulation of immune responses. An appropriate supply of arginine has long been associated with the improvement of immune responses. In addition to being a building block for protein synthesis, arginine serves as a substrate for distinct metabolic pathways that profoundly affect immune cell biology; especially macrophage, dendritic cell and T cell immunobiology. Arginine availability, synthesis, and catabolism are highly interrelated aspects of immune responses and their fine-tuning can dictate divergent pro-inflammatory or anti-inflammatory immune outcomes. Here, we review the organismal pathways of arginine metabolism in humans and rodents, as essential modulators of the availability of this semi-essential amino acid for immune cells. We subsequently review well-established and novel findings on the functional impact of arginine biosynthetic and catabolic pathways on the main immune cell lineages. Finally, as arginine has emerged as a molecule impacting on a plethora of immune functions, we integrate key notions on how the disruption or perversion of arginine metabolism is implicated in pathologies ranging from infectious diseases to autoimmunity and cancer.

Diagnosis and Management of Intraabdominal Infection: Guidelines by the Chinese Society of Surgical Infection and Intensive Care and the Chinese College of Gastrointestinal Fistula Surgeons

The Chinese guidelines for IAI presented here were developed by a panel that included experts from the fields of surgery, critical care, microbiology, infection control, pharmacology, and evidence-based medicine. All questions were structured in population, intervention, comparison, and outcomes format, and evidence profiles were generated. Recommendations were generated following the principles of the Grading of Recommendations Assessment, Development, and Evaluation system or Best Practice Statement (BPS), when applicable. The final guidelines include 45 graded recommendations and 17 BPSs, including the classification of disease severity, diagnosis, source control, antimicrobial therapy, microbiologic evaluation, nutritional therapy, other supportive therapies, diagnosis and management of specific IAIs, and recognition and management of source control failure. Recommendations on fluid resuscitation and organ support therapy could not be formulated and thus were not included. Accordingly, additional high-quality clinical studies should be performed in the future to address the clinicians' concerns.

Urinary Titin N-Fragment Evaluation in a Randomized Controlled Trial of Beta-Hydroxy-Beta-Methylbutyrate for Acute Mild Trauma in Older Adults

The effects of beta-hydroxy-beta-methylbutyrate (HMB) complex administration and the significance of titin, a biomarker of muscle injury, in elderly minor trauma patients in acute phase has not been established. In this single-center, randomized controlled study, trauma patients aged ≥ 70 years with an injury severity score < 16 were included. Titin values on days 1 and 3 were measured and the intervention group received HMB complex (2.4 g of HMB + 14 g of glutamine + 14 g of arginine) and the control group received glutamine complex (7.2 g of protein including 6 g of glutamine). The cross-sectional area of the rectus femoris (RFCSA) on ultrasound, grip strength, and the Barthel Index were assessed on the first day of rehabilitation and after 2 weeks. We analyzed 24 HMB and 25 control participants. Titin values on day 3 correlated with grip strength (r = -0.34, p = 0.03) and the Barthel Index (r = -0.39, p = 0.01) at follow-up. HMB complex supplementation had no effect on the RFCSA (2.41 vs. 2.45 cm², p = 0.887), grip strength (13.3 vs. 13.1 kg, p = 0.946), or the Barthel Index (20.0 vs. 50.0, p = 0.404) at follow-up. Titin values might associate with subsequent physical function. Short-term HMB complex supplementation from acute phase did not ameliorate muscle injury.

Serum Uric Acid Concentrations and Risk of Adverse Outcomes in Patients With COVID-19

BACKGROUND

Although hyperuricemia frequently associates with respiratory diseases, patients with severe coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome (SARS) can show marked hypouricemia. Previous studies on the association of serum uric acid with risk of adverse outcomes related to COVID-19 have produced contradictory results. The precise relationship between admission serum uric acid and adverse outcomes in hospitalized patients is unknown.

METHODS

Data of patients affected by laboratory-confirmed COVID-19 and admitted to Leishenshan Hospital were retrospectively analyzed. The primary outcome was composite and comprised events, such as intensive care unit (ICU) admission, mechanical ventilation, or mortality. Logistic regression analysis was performed to explore the association between serum concentrations of uric acid and the composite outcome, as well as each of its components. To determine the association between serum uric acid and in-hospital adverse outcomes, serum uric acid was also categorized by restricted cubic spline, and the 95% confidence interval (CI) was used to estimate odds ratios (OR).

RESULTS

The study cohort included 1854 patients (mean age, 58 years; 52% women). The overall mean ± SD of serum levels of uric acid was 308 ± 96 µmol/L. Among them, 95 patients were admitted to ICU, 75 patients received mechanical ventilation, and 38 died. In total, 114 patients reached composite end-points (have either ICU admission, mechanical ventilation or death) during hospitalization. Compared with a reference group with estimated baseline serum uric acid of 279-422 µmol/L, serum uric acid values ≥ 423 µmol/L were associated with an increased risk of composite outcome (OR, 2.60; 95% CI, 1.07- 6.29) and mechanical ventilation (OR, 3.01; 95% CI, 1.06- 8.51). Serum uric acid ≤ 278 µmol/L was associated with an increased risk of the composite outcome (OR, 2.07; 95% CI, 1.18- 3.65), ICU admission (OR, 2.18; 95% CI, 1.17- 4.05]), and mechanical ventilation (OR, 2.13; 95% CI, 1.06- 4.28), as assessed by multivariate analysis.

CONCLUSIONS

This study shows that the association between admission serum uric acid and composite outcome of COVID-19 patients was U-shaped. In particular, we found that compared with baseline serum uric acid levels of 279-422 µmol/L, values ≥ 423 µmol/L were associated with an increased risk of composite outcome and mechanical ventilation, whereas levels ≤ 278 µmol/L associated with increased risk of composite outcome, ICU admission and mechanical ventilation.

Omega-3 fatty acid supplementation is associated with favorable outcomes in patients with sepsis: an updated meta-analysis

Objectives

The efficacy of omega-3 fatty acids in the treatment of sepsis is controversial. We conducted an updated meta-analysis to clarify the efficacy of omega-3 fatty acids in patients with sepsis.

Methods

PubMed, EMBASE, and the Cochrane Library were searched for randomized clinical trials (RCTs) on omega-3 fatty acid supplementation in adults with sepsis.

Results

Twenty eligible RCTs involving 1514 patients were included in the meta-analysis. Omega-3 fatty acid supplementation was linked to reductions of mortality (I² = 0, relative risk [RR] = 0.82, 95% confidence interval [CI] = 0.69–0.97), the duration of mechanical ventilation (DMV; I² = 74%, weighted mean difference [WMD] = −2.20, 95% CI = −4.00 to −0.40), and intensive care unit (ICU) length of stay (LOS; I² = 91%, WMD = −3.86, 95% CI = −5.72 to −2.01). Subgroup analysis illustrated that mortality was significantly reduced in patients with sepsis and gastrointestinal dysfunction (RR = 0.5, 95% CI = 0.29–0.86, I² = 0).

Conclusion

Omega-3 fatty acid supplementation might be associated with reduced mortality in patients with sepsis, especially those with gastrointestinal dysfunction. Furthermore, omega-3 fatty acid administration could shorten DMV and ICU LOS.

L-Arginine Enhances Intracellular Killing of Carbapenem-Resistant Klebsiella pneumoniae ST258 by Murine Neutrophils

Carbapenem-resistant Klebsiella pneumoniae ST258 (CRKP-ST258) are a global concern due to their rapid dissemination, high lethality, antibiotic resistance and resistance to components of the immune response, such as neutrophils. Neutrophils are major host mediators, able to kill well-studied and antibiotic-sensitive laboratory reference strains of K. pneumoniae. However, CRKP-ST258 are able to evade neutrophil phagocytic killing, persisting longer in the host despite robust neutrophil recruitment. Here, we show that neutrophils are unable to clear a CRKP-ST258 isolate (KP35). Compared to the response elicited by a prototypic K. pneumoniae ATCC 43816 (KPPR1), the neutrophil intracellular response against KP35 is characterized by equivalent production of reactive oxygen species (ROS) and myeloperoxidase content, but impaired phagosomal acidification. Our results ruled out that this phenomenon is due to a phagocytosis defect, as we observed similar efficiency of phagocytosis by neutrophils infected with KP35 or KPPR1. Genomic analysis of the cps loci of KPPR1 and KP35 suggest that the capsule composition of KP35 explain the high phagocytosis efficiency by neutrophils. Consistent with other reports, we show that KP35 did not induce DNA release by neutrophils and KPPR1 only induced it at 3 h, when most of the bacteria have already been cleared. l-arginine metabolism has been identified as an important modulator of the host immune response and positively regulate T cells, macrophages and neutrophils in response to microbes. Our data show that l-arginine supplementation improved phagosome acidification, increased ROS production and enhanced nitric oxide consumption by neutrophils in response to KP35. The enhanced intracellular response observed after l-arginine supplementation ultimately improved KP35 clearance in vitro. KP35 was able to dysregulate the intracellular microbicidal machinery of neutrophils to survive in the intracellular environment. This process, however, can be reversed after l-arginine supplementation.

The effects of nutritional support on selected laboratory parameters in patients with colorectal cancer undergoing surgical resection of the colon

The benefit of the nutritional support provided to patients with colorectal cancer who have undergone the planned resection of the colon in relation to the laboratory markers of nutrition was examined. And it is currently being discussed, that pre-operative optimization of nutritional status reduces the incidence of post-operative complications in cancer patients and regulates selected laboratory parameters. This was a retrospective study where the treatment group (n = 52) received the enteral nutritional support 21 days prior to the scheduled surgery and the other group was formed of patients without preoperative enteral nutrition (n = 52). Laboratory parameters (CRP, leukocytes, albumin, total proteins) were monitored for at least one month before the planned surgery and just before the operation, and the effect of supplemental enteral nutrition on selected laboratory parameters between these two groups was compared. In a group of patients with enteral nutrition, serum albumin levels increased significantly, while CRP was significantly reduced during preoperative enteral nutrition (albumin S-ALB from 35.42 to 37.48, p = 0.0008, C reactive protein from 26.5 to 14.092, p = 0.0007). Nutritional support 21 days prior to surgery in oncological patients resulted in an improvement in laboratory parameters compared to the group of patients without nutritional enteric support. Malnutrition in patients who are candidates for major surgical intervention is a risk factor for postoperative morbidity and mortality. However, further studies are required to verify the effectiveness of this early nutritional intervention on medium and long-term clinical parameters in different types of cancer.

Surviving sepsis campaign international guidelines for the management of septic shock and sepsis-associated organ dysfunction in children

OBJECTIVES

To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction.

DESIGN

A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process.

METHODS

The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate.

RESULTS

The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 49 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 52 research priorities were identified.

CONCLUSIONS

A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-Associated Organ Dysfunction in Children

OBJECTIVES

To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction.

DESIGN

A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process.

METHODS

The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate.

RESULTS

The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 52 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 49 research priorities were identified.

CONCLUSIONS

A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Bench to bedside review: therapeutic modulation of nitric oxide in sepsis-an update

Nitric oxide is a signalling molecule with an extensive range of functions in both health and disease. Discovered in the 1980s through work that earned the Nobel prize, nitric oxide is an essential factor in regulating cardiovascular, immune, neurological and haematological function in normal homeostasis and in response to infection. Early work implicated exaggerated nitric oxide synthesis as a potentially important driver of septic shock; however, attempts to modulate production through global inhibition of nitric oxide synthase were associated with increased mortality. Subsequent work has shown that regulation of nitric oxide production is determined by numerous factors including substrate and co-factor availability and expression of endogenous regulators. In sepsis, nitric oxide synthesis is dysregulated with exaggerated production leading to cardiovascular dysfunction, bioenergetic failure and cellular toxicity whilst at the same time impaired microvascular function may be driven in part by reduced nitric oxide synthesis by the endothelium. This bench to bedside review summarises our current understanding of the ways in which nitric oxide production is regulated on a tissue and cellular level before discussing progress in translating these observations into novel therapeutic strategies for patients with sepsis.

Effects of a metabolic optimized fast track concept (MOFA) on bowel function and recovery after surgery in patients undergoing elective colon or liver resection: a randomized controlled trial

Background

Enhanced recovery after surgery programs (ERAS) using thoracic epidural anesthesia and perioperative patient conditioning with omega-3 fatty acids (n3FA), glucose control (GC) and on-demand fluid therapy, respectively, showed beneficial effects. In the MOFA- study these components were used together in patients undergoing colon or liver surgery. We hypothesized that the use of a perioperative MOFA program improves intestine function represented as time to the first postoperative bowel movement in adult patients compared to standard ERAS.

Methods

After BfArM and IRB approval 100 patients were enrolled in this prospective randomized controlled trial. All patients received ERAS therapy (control). In addition, the MOFA group received 0.2 g/kg fish oil (Omegaven®), preoperatively, followed by a 48 h continuous infusion of 0.2 g/kg/d n3FA; and GC was kept below < 8 mmol/L. Pre- and postoperatively energy drinks were administered.

Results

As compared to control group the MOFA concept resulted in an earlier onset of flatulence by 14 h (46.6 ± 25.7, 32.0 ± 17.9, p = 0.030, hours, control vs. MOFA, respectively). Effects on onset of bowel movement were not observed (74.5 ± 30.4, 66.4 ± 29.2, p = 0.163, hours, control vs. MOFA, respectively). The disease severity (SAPS II score; p = 0.720) as well as deployment of resources (TISS 28 score, p = 0.709) did not differ between groups. No statistic significant difference between MOFA and control group regarding inflammation, impairment of coagulation, length of hospital stay or incidence of postoperative surgical complications were observed.

Conclusions

The MOFA concept did not result in an improvement of intestine function or faster recovery after elective colon or liver surgery compared to standard ERAS therapy. Omega-3 fatty acids showed no impairment of coagulation or improved resolution of inflammation. Further trials in a larger patient collective are needed to investigate potential beneficial effects of omega-3 fatty acids in abdominal surgery.

Trial registration

This trial was prospectively registered at the European Union Clinical Trials Register (EuDraCT 2005–004814-33, date: 10-05-2005, https://www.clinicaltrialsregister.eu/ctr-search/search?query=2005-004814-33+).

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0823-6) contains supplementary material, which is available to authorized users.

Current evidence on ω-3 fatty acids in enteral nutrition in the critically ill: A systematic review and meta-analysis

Fish oil exerts anti-inflammatory and immunomodulatory properties that may be beneficial for critically ill patients, thus multiple randomized controlled trials and meta-analyses have been performed. However, controversy remains as to whether fish oil-enriched enteral nutrition can improve clinical outcomes in adult critically ill patients in intensive care units (ICUs). The aim of this study was to provide an up-to-date systematic review and meta-analysis of all randomized controlled trials of fish oil-containing enteral nutrition addressing relevant clinical outcomes in critically ill patients. A systematic literature search was conducted. The primary outcome was 28-d mortality. Secondary outcomes were ICU and hospital mortality, ICU and hospital length of stay (LOS), ventilation duration, and infectious complications. Predefined subgroup and sensitivity analyses were performed. Twenty-four trials, enrolling 3574 patients, met the inclusion criteria. The assessment of risk for bias showed that most of included studies were of moderate quality. The overall results revealed no significant effects of enteral fish oil supplementation on 28-d, ICU or hospital mortality. However, ICU LOS and ventilation duration were significantly reduced in patients receiving fish oil supplementation. Furthermore, subgroup analysis revealed a significant reduction in 28-d mortality, ICU LOS, and ventilation duration in patients with acute respiratory distress syndrome but not in other subgroups. When comparing high- and low-quality trials, significant reductions in 28-d mortality and ventilation duration in low-quality trials only were observed. Regarding ICU LOS a significant reduction was observed in high-quality trials; whereas only a trend was observed in low-quality trials. No significant effects on hospital LOS or infectious complications were observed in overall or subgroup analyses. Enteral fish oil supplementation cannot be recommended for critically ill patients, as strong scientific evidence for improved clinical benefits was not found. There is a signal of mortality benefit in patients with acute respiratory distress syndrome; however, results are based on low-quality studies. Further research should focus on the relation between the individual critically ill patients' immune response, the administration of fish oil, and clinical outcomes.

Correlation analysis of omega-3 fatty acids and mortality of sepsis and sepsis-induced ARDS in adults: data from previous randomized controlled trials

Objective

This study aimed to investigate the possible effect of omega-3 fatty acids on reducing the mortality of sepsis and sepsis-induced acute respiratory distress syndrome (ARDS) in adults.

Methods

Medline, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI) database, WangFang database, and Chinese BioMedical Literature Database from their inception to March 6, 2017, were searched using systematic review researching methods. Five factors were analyzed to investigate the correlation between omega-3 fatty acids (either parenteral or enteral supplementation) and mortality rate.

Results

Forty randomized controlled trials (RCTs) were initially included, but only 25 of them assessed mortality. Of these RCTs, nine used enteral nutrition (EN) and 16 used parenteral nutrition (PN). The total mortality rate in the omega-3 fatty acid group was lower than that in the control group. However, the odds ratio (OR) value was not significantly different in the EN or PN subgroup. Eighteen RCTs including 1790 patients with similar severity of sepsis and ARDS were also analyzed. The OR value was not significantly different in the EN or PN subgroup. Omega-3 fatty acids did not show positive effect on improving mortality of sepsis-induced ARDS (p = 0.39). But in EN subgroup, omega-3 fatty acids treatment seemed to have some benefits in reducing mortality rate (p = 0.04). In the RCTs including similar baseline patients, partial correlation analysis found that the concentration ratio of n-6 to n-3 fatty acids had positive correlation with reduction of mortality (RM) (γ = 0.60, P = 0.02), whereas the total number of each RCT had negative correlation with RM (γ = − 0.54, P = 0.05).

Conclusions

This review found that omega-3 fatty acid supplementation could reduce the mortality rate of sepsis and sepsis-induced ARDS. However, further investigation based on suitable concentrations and indications is needed to support the findings.

Studies into Slo1 K+ channels and their ligand docosahexaenoic acid in murine sepsis to delineate off-target effects of immunonutrition

AIMS

Studies on omega-3 fatty acids, including docosahexaenoic acid (DHA), reveal diverging results: Their intake is recommended in cardiovascular disease and major surgery, while evidence argues against use in septic patients. DHA mediates its blood-pressure-lowering effect through Slo1 channels that are expressed on cardiovascular and immune cells. We hypothesised that conflicting effects of immunonutrition could be explained by the influence of omega-3 fatty acids on systemic blood pressure or immune effector cells through Slo1.

MAIN METHODS

The effect of DHA on blood pressure was analysed in septic wild-type (WT) mice. Septic WT and Slo1 knockout (KO) mice were compared regarding survival, clinical presentation, haematology, cytokine release and bacterial burden. Cytokine expression and release of bone marrow derived macrophages (BMDM) from WT and Slo1 KO mice was assessed in response to LPS.

KEY FINDINGS

The significant blood-pressure-lowering effect of DHA in healthy animals was blunted in already hypotensive septic mice. Septic Slo1 KO mice displayed moderately lower bacterial burden in blood and lungs compared with WT, which did not translate into improved survival. Slo1 KO BMDM presented lower IL-6 levels in response to LPS, an effect that was abolished in the presence of DHA. More importantly, the strong inhibitory effect of DHA on IL-6 release was also observed in Slo1 KO BMDM.

SIGNIFICANCE

The controversial effects of immunonutrition in sepsis are unlikely to be primarily explained by the influence of DHA on blood pressure or effects on immune response mediated through Slo1 channels.

Effect of immunonutrition on colorectal cancer patients undergoing surgery: a meta-analysis

PURPOSE

Immunonutrition has been used to prevent the complications after colorectal elective surgery. This systematic review aimed to analyze and assess the effect of immunonutrition on colorectal cancer patients who received elective surgery.

METHODS

Three electronic databases (Medline, Embase, Cochrane) were used to search the latent studies which investigated the effects of enteral immunonutrition (EIN) compared with standard enteral nutrition (EN) or parenteral immunonutrition (PIN) compared with standard parenteral nutrition (PN) on colorectal cancer patients who are undergoing surgery until 21st of April, 2017. Meta-analysis was conducted to calculate odd risk (OR), mean difference (MD), or standard mean difference (SMD) with 95% confidence interval (CI), and heterogeneity was tested by Q test.

RESULTS

Nine publications were included. The meta-analysis results presented that EIN improved the length of hospital stay (pooled MD, 2.53; 95% CI, 1.29-3.41), infectious complications (pooled OR, 0.33; 95% CI, 0.21-0.53) which contains the Surgical Site Infections (pooled OR, 0.25; 95% CI, 0.22-0.58) and Superficial/Deep incisional infections (pooled OR, 0.27; 95% CI, 0.12-0.64); meanwhile, PIN improved the length of hospital stay (pooled MD, 2.66; 95% CI, 0.62-4.76), IL-6 (pooled MD, - 6.09; 95% CI, - 10.11 to - 2.07), CD3 (pooled MD, 7.50; 95% CI, 3.57-11.43), CD4 (pooled MD, 5.47; 95% CI, 2.54-8.40), and CD4/CD8 (pooled MD, 0.50; 95% CI, 0.22-0.78); the level of CD8 was lower (pooled MD, - 4.32; 95% CI, - 7.09 to - 1.55) in PIN.

CONCLUSION

Immunonutrition could be an effective approach to enhance the immune function of colorectal cancer patients undergoing elective surgery and to improve the clinical and laboratory outcomes.

Effects of early enteral nutrition supplemented with collagen peptides on post-burn inflammatory responses in a mouse model

The effect of early enteral nutrition (EN) supplemented with Alaska pollock skin-derived collagen peptides (CPs) on post-burn inflammatory responses was investigated in a mouse model. Male blab/c mice were randomly assigned to four groups: a sham burn (SB) group, a control group (burn + EN + glycine, BE), a positive control group (burn + EN + glutamine, BEG) and a treatment group (burn + EN + CPs, BEC). Burn-induced increases of serum endotoxin level, and systemic and intestinal concentration of TNF-α and IL-6 were attenuated in BEG and BEC at post-burn day (PBD) 1, 3 and 7 (p < 0.05 vs. BE). Notably, BEC revealed a prominent decrease of the serum endotoxin level, TNF-α and IL-6 as compared to BEG at PBD 7 (p < 0.05). Furthermore, EN supplemented with CPs diminished the phosphorylation of intestinal NF-κB p65 and simultaneously down-regulated the mRNA expression of TNF-α and IL-6 in small intestine (p < 0.05 vs. BE). Also, it demonstrated a comparable effect with glutamine in ameliorating post-burn inflammatory responses in mice with burns. Therefore, CPs could be considered as a potential immunonutrient supplement in EN to improve post-burn outcomes in burn patients.

Critical Care Nutrition Support Best Practices: Key Differences Between Canadian and American Guidelines

Since 2015, Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition and Canadian critical care nutrition support guidelines have both been updated. Despite a similar evidentiary basis, there remain key differences between guideline recommendations. These differences in recommendations may pose confusion for the clinician and may encumber widespread applicability. The aim of this review was to enhance practitioner confidence in applying critical care nutrition support guidelines to patient care in their settings by outlining the similarities and differences between the American and Canadian methods for guideline development and describing the key differences and reasons behind the differences.

The effect of metformin on survival of patients with pancreatic cancer: a meta-analysis

We conducted a meta-analysis to analyse the effect of metformin on survival of pancreatic cancer patients at various stages. We performed a systematic search of PubMed, Embase, Cochrane, and Web of Science to identify all relevant studies. Summary hazard ratios (HR) of survival and 95% confidence intervals (95% CI) were calculated with a fixed or random effects model according to inter-study heterogeneity. Nine retrospective cohort studies and two randomized controlled trials (RCTs) were eligible. There was a significant improvement in survival (HR = 0.86, 95% CI 0.76–0.97; P < 0.05) in the metformin group compared with control. Subgroup analysis indicated that metformin improved survival in patients with resection (HR = 0.79, 95% CI 0.69–0.91; P < 0.05) and patients with locally advanced tumors (HR = 0.68, 95% CI 0.55–0.84; P < 0.05) but not in patients with metastatic tumors, even when RCT data were included (HR = 0.99, 95% CI 0.70–1.40; P > 0.05), or were excluded (HR = 0.89, 95% CI 0.61–1.31; P > 0.05). This meta-analysis indicated that the effect of metformin does correlate with tumor stage but should be prudently considered given the limited and variable studies performed to data.

Omega-3 supplementation in patients with sepsis: a systematic review and meta-analysis of randomized trials

BACKGROUND

Nutritional supplementation of omega-3 fatty acids has been proposed to modulate the balance of pro- and anti-inflammatory mediators in sepsis. If proved to improve clinical outcomes in critically ill patients with sepsis, this intervention would be easy to implement. However, the cumulative evidence from several randomized clinical trials (RCTs) remains unclear.

METHODS

We searched the Cochrane Library, MEDLINE, and EMBASE through December 2016 for RCTs on parenteral or enteral omega-3 supplementation in adult critically ill patients diagnosed with sepsis or septic shock. We analysed the included studies for mortality, intensive care unit (ICU) length of stay, and duration of mechanical ventilation, and used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the quality of the evidence for each outcome.

RESULTS

A total of 17 RCTs enrolling 1239 patients met our inclusion criteria. Omega-3 supplementation compared to no supplementation or placebo had no significant effect on mortality [relative risk (RR) 0.85; 95% confidence interval (CI) 0.71, 1.03; P = 0.10; I ² = 0%; moderate quality], but significantly reduced ICU length of stay [mean difference (MD) -3.79 days; 95% CI -5.49, -2.09; P < 0.0001, I ² = 82%; very low quality] and duration of mechanical ventilation (MD -2.27 days; 95% CI -4.27, -0.27; P = 0.03, I ² = 60%; very low quality). However, sensitivity analyses challenged the robustness of these results.

CONCLUSION

Omega-3 nutritional supplementation may reduce ICU length of stay and duration of mechanical ventilation without significantly affecting mortality, but the very low quality of overall evidence is insufficient to justify the routine use of omega-3 fatty acids in the management of sepsis.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012."

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Nutrition and metabolism in burn patients

Severe burn causes significant metabolic derangements that make nutritional support uniquely important and challenging for burned patients. Burn injury causes a persistent and prolonged hypermetabolic state and increased catabolism that results in increased muscle wasting and cachexia. Metabolic rates of burn patients can surpass twice normal, and failure to fulfill these energy requirements causes impaired wound healing, organ dysfunction, and susceptibility to infection. Adequate assessment and provision of nutritional needs is imperative to care for these patients. There is no consensus regarding the optimal timing, route, amount, and composition of nutritional support for burn patients, but most clinicians advocate for early enteral nutrition with high-carbohydrate formulas.

Nutritional support must be individualized, monitored, and adjusted throughout recovery. Further investigation is needed regarding optimal nutritional support and accurate nutritional endpoints and goals.

Admission levels of asymmetric and symmetric dimethylarginine predict long-term outcome in patients with community-acquired pneumonia

BACKGROUND

During infection, there is an activation of the L-arginine-nitric-oxide pathway, with a shift from nitric oxide synthesis to a degradation of L-arginine to its metabolites, asymmetric and symmetric dimethylarginine (ADMA and SDMA). However, the prognostic implications for short-term or long-term survival remains unclear. We investigated the association of L-arginine, ADMA, and SDMA with adverse clinical outcomes in a well-defined cohort of patients with community-acquired pneumonia (CAP).

METHODS

We measured L-arginine, ADMA, and SDMA in 268 CAP patients from a Swiss multicenter trial by mass spectrometry and used Cox regression models to investigate associations between blood marker levels and disease severity as well as mortality over a period of 6 years.

RESULTS

Six-year mortality was 44.8%. Admission levels of ADMA and SDMA (μmol/L) were correlated with CAP severity as assessed by the pneumonia severity index (r = 0.32, p < 0.001 and r = 0.56, p < 0.001 for ADMA and SDMA, respectively) and higher in 6-year non-survivors versus survivors (median 0.62 vs. 0.48; p < 0.001 and 1.01 vs. 0.85; p < 0.001 for ADMA and SDMA, respectively). Both ADMA and SDMA were significantly associated with long-term mortality (hazard ratios [HR] 4.44 [95% confidence intervals (CI) 1.84 to 10.74] and 2.81 [95% CI 1.45 to 5.48], respectively). The effects were no longer significant after multivariate adjustment for age and comorbidities. No association of L-arginine with severity and outcome was found.

CONCLUSIONS

Both ADMA and SDMA show a severity-dependent increase in patients with CAP and are strongly associated with mortality. This association is mainly explained by age and comorbidities.

TRIAL REGISTRATION

ISRCTN95122877 . Registered 31 July 2006.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012".

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Metabolic and Nutritional Aspects of Acute Renal Failure in Critically Ill Patients Requiring Continuous Renal Replacement Therapy

Acute renal failure (ARF) is rarely an isolated process but is often a complication of underlying conditions such as sepsis, trauma, and multiple-organ failure in critically ill patients. As such, concomitant clinical conditions significantly affect patient outcome. Poor nutritional status is a major factor in increasing patients' morbidity and mortality. Malnutrition in ARF patients is caused by hypercatabolism and hypermetabolism that parallel the severity of illness. When dialytic intervention is indicated, continuous renal replacement therapy (CRRT) is a commonly used alternative to intermittent hemodialysis because it is well tolerated by hemodynamically unstable patients. This paper reviews the metabolic and nutritional alterations associated with ARF and provides recommendations regarding the nutritional, fluid, electrolyte, micronutrient, and acid-base management of these patients. The basic principles of CRRT are addressed, along with their nutritional implications in critically ill patients. A patient case is presented to illustrate the clinical application of topics covered within the paper.

Nutrition and metabolism in burn patients

Severe burn causes significant metabolic derangements that make nutritional support uniquely important and challenging for burned patients. Burn injury causes a persistent and prolonged hypermetabolic state and increased catabolism that results in increased muscle wasting and cachexia. Metabolic rates of burn patients can surpass twice normal, and failure to fulfill these energy requirements causes impaired wound healing, organ dysfunction, and susceptibility to infection. Adequate assessment and provision of nutritional needs is imperative to care for these patients. There is no consensus regarding the optimal timing, route, amount, and composition of nutritional support for burn patients, but most clinicians advocate for early enteral nutrition with high-carbohydrate formulas. Nutritional support must be individualized, monitored, and adjusted throughout recovery. Further investigation is needed regarding optimal nutritional support and accurate nutritional endpoints and goals.

The Management of Sepsis: A Practical Review

The incidence of the sepsis syndrome has increased dramatically in the last few decades. During this time we have gained new insights into the pathophysiologic mechanisms leading to organ dysfunction in sepsis and the importance of the host-bacterial interactions in mediating many of these processes. This knowledge has led to new therapeutic approaches and the investigation of a number of novel agents. An assessment of these approaches is presented to aid clinicians in the management of patients with severe sepsis. Criteria used to select studies included their relevance to the management of sepsis and their pertinence to clinicians. Appropriate antibiotic selection and volume resuscitation remain the cornerstone of treatment of septic patients. Hydroxyethyl starch solutions have theoretical advantages over crystalloids; there is, however, no data that the type of resuscitation fluid alters outcome. Vasoactive agents are required in patients who remain hemodynamically unstable or have evidence of tissue hypoxia after adequate volume resuscitation. Although dopamine is widely used, dobutamine and norepinephrine are our vasoactive agents of choice. Dopamine has no proven role in oliguric patients, with early dialysis recommended in patients with acute renal failure. The preferred method of renal replacement therapy remains to be determined. Blood products should be used cautiously in patients with disseminated intravascular coagulation. Therapeutic strategies that interfere with the immune system have not been proven to improve the outcome in unselected groups of patients. However, immunomodulation may prove to have a role in select subgroups of patients. Antibiotic therapy and intensive physiological support continues to be the main approach to the management of patients with severe sepsis. Despite the development of numerous novel therapeutic agents, these drugs have not been demonstrated to improve patient outcome.

Parenteral or Enteral Arginine Supplementation Safety and Efficacy

Arginine supplementation has the potential to improve the health of patients. Its use in hospitalized patients has been a controversial topic in the nutrition literature, especially concerning supplementation of septic patients. In this article, we review the relevant literature both for and against the use of arginine in critically ill, surgical, and hospitalized patients. The effect of critical illness on arginine metabolism is reviewed, as is its use in septic and critically ill patients. Although mounting evidence supports immunonutrition, there are only a few studies that suggest that this is safe in patients with severe sepsis. The use of arginine has been shown to benefit a variety of critically ill patients. It should be considered for inclusion in combinations of immunonutrients or commercial formulations for groups in whom its benefit has been reported consistently, such as those who have suffered trauma and those in acute surgical settings. The aims of this review are to discuss the role of arginine in health, the controversy surrounding arginine supplementation of septic patients, and the use of arginine in critically ill patients.

Nutrition Support in Adult Trauma Patients

Nutrition supplementation is paramount to the care of severely injured patients. Despite its widespread use in trauma patients, many areas of clinical practice remain controversial. The purpose of this paper is to critically review the literature studying the use of enteral vs parenteral nutrition (PN) and to provide the rationale for early enteral nutrition. Additional controversies confronting clinicians are reviewed, including the use of immune-enhancing agents and the optimal site for enteral nutrition delivery (gastric vs small intestinal). Evidence-based recommendations for clinical practice are presented when available.

The systemic inflammatory response syndrome

The systemic inflammatory response syndrome (SIRS) describes the clinical presentation of patients with systemic activation of the inflammatory response from any underlying cause. SIRS is a common problem in acute medical and surgical practice and an important cause of morbidity and mortality. As a consequence of SIRS, patients may develop multiple organ dysfunction syndrome and acute respiratory distress syndrome (ARDS). Over the recent years our understanding of the inflammatory response in SIRS has increased, but as yet specific immunomodulatory therapies have not proved useful. The mainstay of treatment for patients with SIRS and ARDS remains a general supportive care. It is in this area that more encouraging advances are being made, particularly in the management of invasive ventilation and nutrition. In this review we summarize the definitions, epidemiology and pathophysiology of SIRS, ARDS and related conditions. We then give a description of the clinical consequences and treatment of SIRS and ARDS with an emphasis on current aspects of supportive care.

When Is It Appropriate to Use Arginine in Critical Illness?

In health, arginine is considered a nonessential amino acid but can become an essential amino acid (ie, conditionally essential amino acid) during periods of metabolic or traumatic stress as endogenous arginine supply is inadequate to meet physiologic demands. Arginine depletion in critical illness is associated with impairments in microcirculatory blood flow, impaired wound healing, and T-cell dysfunction. The purpose of this review is to (1) describe arginine metabolism and role in health and critical illness, (2) describe the relationship between arginine and asymmetric dimethylarginine, and (3) review studies of supplemental arginine in critically ill patients.