Effects of an omega-3 fatty acid-enriched lipid emulsion on eicosanoid synthesis in acute respiratory distress syndrome (ARDS): A prospective, randomized, double-blind, parallel group study

Critically Ill Older Adults' Representation in Intervention Trials: A Systematic Review

OBJECTIVES

Older adults may be under-represented in critical care research, and results may not apply to this specific population. Our primary objective was to evaluate the prevalence of inclusion of older adults across critical care trials focused on common ICU conditions or interventions. Our secondary objective was to evaluate whether older age was used as a stratification variable for randomization or outcome analysis.

DESIGN SETTING AND SUBJECTS

We performed a systematic review of previously published systematic reviews of randomized controlled trials (RCTs) in critical care. We searched PubMed, Ovid, CENTRAL, and Cochrane from 2009 to 2022. Systematic reviews of any interventions across five topics: acute respiratory distress syndrome (ARDS), sepsis/shock, nutrition, sedation, and mobilization were eligible.

MAIN RESULTS

We identified 216 systematic reviews and included a total of 253 RCTs and 113,090 patients. We extracted baseline characteristics and the reported proportion of older adults. We assessed whether any upper age limit was an exclusion criterion for trials, whether age was used for stratification during randomization or data analysis, and if age-specific subgroup analysis was present. The most prevalent topic was sepsis (78 trials, 31%), followed by nutrition (62 trials, 25%), ARDS (39 trials, 15%), mobilization (38 trials, 15%), and sedation (36 trials, 14%). Eighteen trials (7%) had exclusion criteria based on older age. Age distribution with information on older adults prevalence was given in six trials (2%). Age was considered in the analysis of ten trials (5%) using analytic methods to evaluate the outcome stratified by age.

Conclusions

In this systematic review, the proportion of older critically ill patients is undetermined, and it is unclear how age is or is not an effect modifier or to what extent the results are valid for older adult groups. Reporting age is important to guide clinicians in personalizing care. These results highlight the importance of incorporating older critically ill patients in future trials to ensure the results are generalizable to this growing population.

Omega-3 fatty acids in parenteral nutrition - A systematic review with network meta-analysis on clinical outcomes

BACKGROUND & AIMS

Accumulating scientific evidence supports the benefits of parenteral nutrition (PN) with fish oil (FO) containing intravenous lipid emulsions (ILEs) on clinical outcomes. Yet, the question of the most effective ILE remains controversial. We conducted a network meta-analysis (NMA) to compare and rank different types of ILEs in terms of their effects on infections, sepsis, ICU and hospital length of stay, and in-hospital mortality in adult patients.

METHODS

MEDLINE, EMBASE, and Web of Science databases were searched for randomized controlled trials (RCTs) published up to May 2022, investigating ILEs as a part of part of PN covering at least 70% of total energy provision. Lipid emulsions were classified in four categories: FO-ILEs, olive oil (OO)-ILEs, medium-chain triglyceride (MCT)/soybean oil (SO)-ILEs, and pure SO-ILEs. Data were statistically combined through Bayesian NMA and the Surface Under the Cumulative RAnking (SUCRA) was calculated for all outcomes.

RESULTS

1651 publications were retrieved in the original search, 47 RCTs were included in the NMA. For FO-ILEs, very highly credible reductions in infection risk versus SO-ILEs [odds ratio (OR) = 0.43 90% credibility interval (CrI) (0.29-0.63)], MCT/soybean oil-ILEs [0.59 (0.43-0.82)], and OO-ILEs [0.56 (0.33-0.91)], and in sepsis risk versus SO-ILEs [0.22 (0.08-0.59)], as well as substantial reductions in hospital length of stay versus SO-ILEs [mean difference (MD) = -2.31 (-3.14 to -1.59) days] and MCT/SO-ILEs (-2.01 (-2.82 to -1.22 days) were shown. According to SUCRA score, FO-ILEs were ranked first for all five outcomes.

CONCLUSIONS

In hospitalized patients, FO-ILEs provide significant clinical benefits over all other types of ILEs, ranking first for all outcomes investigated.

REGISTRATION NO

PROSPERO 2022 CRD42022328660.

Omega-3 Polyunsaturated Fatty Acids (n-3 PUFAs) for Immunomodulation in COVID-19 Related Acute Respiratory Distress Syndrome (ARDS)

Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), might be complicated by Acute Respiratory Distress Syndrome (ARDS) caused by severe lung damage. It is relevant to find treatments for COVID-19-related ARDS. Currently, DHA and EPA n-3 PUFAs, known for their immunomodulatory activities, have been proposed for COVID-19 management, and clinical trials are ongoing. Here, examining COVID-19-related ARDS immunopathology, we reference in vitro and in vivo studies, indicating n-3 PUFA immunomodulation on lung microenvironment (bronchial and alveolar epithelial cells, macrophages, infiltrating immune cells) and ARDS, potentially affecting immune responses in COVID-19-related ARDS. Concerning in vitro studies, evidence exists of the potential anti-inflammatory activity of DHA on airway epithelial cells and monocytes/macrophages; however, it is necessary to analyze n-3 PUFA immunomodulation using viral experimental models relevant to SARS-CoV-2 infection. Then, although pre-clinical investigations in experimental acute lung injury/ARDS revealed beneficial immunomodulation by n-3 PUFAs when extracellular pathogen infections were used as lung inflammatory models, contradictory results were reported using intracellular viral infections. Finally, clinical trials investigating n-3 PUFA immunomodulation in ARDS are limited, with small samples and contradictory results. In conclusion, further in vitro and in vivo investigations are needed to establish whether n-3 PUFAs may have some therapeutic potential in COVID-19-related ARDS.

Plasma and bronchoalveolar lavage fluid oxylipin levels in experimental porcine lung injury

Inflammatory signaling pathways involving eicosanoids and other regulatory lipid mediators are a subject of intensive study, and a role for these in acute lung injury is not yet well understood. We hypothesized that oxylipin release from lung injury could be detected in bronchoalveolar lavage fluid and in plasma. In a porcine model of surfactant depletion, ventilation with hyperinflation was assessed. Bronchoalveolar lavage and plasma samples were analyzed for 37 different fatty acid metabolites (oxylipins). Over time, hyperinflation altered concentrations of 4 oxylipins in plasma (TXB₂, PGE₂, 15-HETE and 11-HETE), and 9 oxylipins in bronchoalveolar lavage fluid (PGF_2α, PGE₂, PGD₂, 12,13-DiHOME, 11,12-DiHETrE, 13-HODE, 9-HODE, 15-HETE, 11-HETE). Acute lung injury caused by high tidal volume ventilation in this porcine model was associated with rapid changes in some elements of the oxylipin profile, detectable in lavage fluid, and plasma. These oxylipins may be relevant in the pathogenesis of acute lung injury by hyperinflation.

Taiwan Society of Colon and Rectum Surgeons (TSCRS) Consensus for Anti-Inflammatory Nutritional Intervention in Colorectal Cancer

Malnutrition and systemic inflammatory response (SIR) frequently occur in patients with colorectal cancer (CRC) and are associated with poor prognosis. Anti-inflammatory nutritional intervention is not only a way to restore the malnourished status but also modulate SIR. Nine experts, including colorectal surgeons, physicians and dieticians from 5 hospitals geographically distributed in Taiwan, attended the consensus meeting in Taiwan Society of Colon and Rectum Surgeons for a 3-round discussion and achieved the consensus based on a systematic literature review of clinical studies and published guidelines. The consensus recommends that assessment of nutritional risk and SIR should be performed before and after CRC treatment and appropriate nutritional and/or anti-inflammatory intervention should be adapted and provided accordingly.

Omega-6 sparing effects of parenteral lipid emulsions-an updated systematic review and meta-analysis on clinical outcomes in critically ill patients

BACKGROUND

Parenteral lipid emulsions in critical care are traditionally based on soybean oil (SO) and rich in pro-inflammatory omega-6 fatty acids (FAs). Parenteral nutrition (PN) strategies with the aim of reducing omega-6 FAs may potentially decrease the morbidity and mortality in critically ill patients.

METHODS

A systematic search of MEDLINE, EMBASE, CINAHL and CENTRAL was conducted to identify all randomized controlled trials in critically ill patients published from inception to June 2021, which investigated clinical omega-6 sparing effects. Two independent reviewers extracted bias risk, treatment details, patient characteristics and clinical outcomes. Random effect meta-analysis was performed.

RESULTS

1054 studies were identified in our electronic search, 136 trials were assessed for eligibility and 26 trials with 1733 critically ill patients were included. The median methodologic score was 9 out of 14 points (95% confidence interval [CI] 7, 10). Omega-6 FA sparing PN in comparison with traditional lipid emulsions did not decrease overall mortality (20 studies; risk ratio [RR] 0.91; 95% CI 0.76, 1.10; p = 0.34) but hospital length of stay was substantially reduced (6 studies; weighted mean difference [WMD] - 6.88; 95% CI - 11.27, - 2.49; p = 0.002). Among the different lipid emulsions, fish oil (FO) containing PN reduced the length of intensive care (8 studies; WMD - 3.53; 95% CI - 6.16, - 0.90; p = 0.009) and rate of infectious complications (4 studies; RR 0.65; 95% CI 0.44, 0.95; p = 0.03). When FO was administered as a stand-alone medication outside PN, potential mortality benefits were observed compared to standard care.

CONCLUSION

Overall, these findings highlight distinctive omega-6 sparing effects attributed to PN. Among the different lipid emulsions, FO in combination with PN or as a stand-alone treatment may have the greatest clinical impact. Trial registration PROSPERO international prospective database of systematic reviews (CRD42021259238).

Assessment of Polyunsaturated Fatty Acids on COVID-19-Associated Risk Reduction

Pooled evidence conveys the association between polyunsaturated fatty acids and infectious disease. SARS-CoV-2, an enveloped mRNA virus, was also reported to interact with polyunsaturated fatty acids. The present review explores the possible mode of action, immunology, and consequences of these polyunsaturated fatty acids during the viral infection. Polyunsaturated fatty acids control protein complex formation in lipid rafts associated with the function of two SARS-CoV-2 entry gateways: angiotensin-converting enzyme-2 and cellular protease transmembrane protease serine-2. Therefore, the viral entry can be mitigated by modulating polyunsaturated fatty acids contents in the body. α-Linolenic acid is the precursor of two clinically important eicosanoids eicosapentaenoic acid and docosahexaenoic acid, the members of ω-3 fats. Resolvins, protectins, and maresins derived from docosahexaenoic acid suppress inflammation and augment phagocytosis that lessens microbial loads. Prostaglandins of 3 series, leukotrienes of 5 series, and thromboxane A₃ from eicosapentaenoic acid exhibit anti-inflammatory, vasodilatory, and platelet anti-aggregatory effects that may also contribute to the control of pre-existing pulmonary and cardiac diseases. In contrast, ω-6 linoleic acid-derived arachidonic acid increases the prostaglandin G₂, lipoxins A₄ and B₄, and thromboxane A₂. These cytokines are pro-inflammatory and enhance the immune response but aggravate the COVID-19 severity. Therefore, the rational intake of ω-3-enriched foods or supplements might lessen the complications in COVID-19 and might be a preventive measure.

Graphic Abstract

Therapeutic effect of pH-Responsive dexamethasone prodrug nanoparticles on acute lung injury

Acute lung injury/inflammation (ALI) is usually caused by various injury factors inside and outside the lung, which can be transformed into acute respiratory distress syndrome (ARDS) in severe cases. Alveolar macrophages play a key role in the pathogenesis of ALI, which regulate inflammatory responses by secreting inflammatory mediators. Therefore, we prepared dexamethasone (DXM)/mannose co-modified branched polyethyleneimine (PEI) (DXM-PEI-mannose, DPM) prodrug nanopartcales, which could effectively target the mannose receptor (MR) on the surface of alveolar macrophages and be used for the treatment of ALI. The DXM-PEI (DP) prodrug was obtained by linking DXM with branched PEI through Schiff base reaction. Subsequently, the pH-responsive DPM prodrug was obtained by using mannose-targeted head modification. The DPM prodrug NPs with a particle size of 115 ± 1 nm, a polydispersity index (PDI) value of 0.054 ± 0.018, and a zeta potential of 31 ± 1 mV were obtained by cross-linking. The drug loading of DPM prodrug NPs measured by the acid hydrolysis method was 51.88%, which had good serum stability and biocompatibility. By comparing the stability and property release of prodrug NPs under different pH (7.4 and 5.0) conditions, it showed that DPM prodrug NPs had certain sensitivity to the micro-acid environment. To study the targeting of mouse mononuclear macrophages, mannose-modified prodrug NPs showed significant in vitro targeting. Moreover, prodrug NPs showed good anti-inflammatory activity in vitro, which was significantly different from free drugs. In vivo biodistribution experiments also showed that it had a long-term lung targeting effect. DPM prodrug NPs also had a good therapeutic effect on ALI. In conclusion, the mannose-modified DXM prodrug NPs delivery system could specifically target lung tissues and have a good therapeutic effect, which might be useful for the treatment of lung diseases.

Guidelines for the provision of nutrition support therapy in the adult critically Ill patient: American society for parenteral and enteral nutrition

BACKGROUND

New randomized controlled trials have been conducted since publication of the 2016 ASPEN/SCCM critical care nutrition guideline. This guideline updates recommendations for foundational questions central to critical care nutrition support.

METHODS

The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process was used to develop and summarize evidence for clinical practice recommendations. Clinical outcomes were assessed for (1) higher vs lower energy dose (2) higher vs lower protein dose (3) exclusive isocaloric PN vs EN (4) supplemental PN (SPN) plus EN vs EN alone (5a) mixed oil lipid injectable emulsions (ILE) vs soybean oil, and (5b) Fish oil (FO) containing ILE vs non-FO ILE. To assess safety, weight based energy intake was plotted against hospital mortality when study heterogeneity precluded meaningful Forest plot inferences.

RESULTS

Between 1/1/2001 and 07/15/2020, 2,320 citations were identified and data were abstracted from 39 trials, including 20,578 participants. Patients receiving FO had decreased pneumonia rates of uncertain clinical significance. Otherwise, there were no differences for any outcome in any question. Due to lack in certainty regarding harm, the energy prescription recommendation was decreased to 12-25kcal/kg/day.

CONCLUSION

No differences in clinical outcomes were identified among numerous nutritional interventions, including higher energy or protein intake, isocaloric PN or EN, supplemental PN, or different ILEs. As more consistent critical care nutrition support data become available, more precise recommendations will be possible. In the meantime, clinical judgment and close monitoring are needed. This paper was approved by the ASPEN Board of Directors.  This article is protected by copyright. All rights reserved.

Dietary Supplements and Nutraceuticals under Investigation for COVID-19 Prevention and Treatment

Coronavirus disease 2019 (COVID-19) has caused global disruption and a significant loss of life. Existing treatments that can be repurposed as prophylactic and therapeutic agents may reduce the pandemic's devastation. Emerging evidence of potential applications in other therapeutic contexts has led to the investigation of dietary supplements and nutraceuticals for COVID-19. Such products include vitamin C, vitamin D, omega 3 polyunsaturated fatty acids, probiotics, and zinc, all of which are currently under clinical investigation. In this review, we critically appraise the evidence surrounding dietary supplements and nutraceuticals for the prophylaxis and treatment of COVID-19. Overall, further study is required before evidence-based recommendations can be formulated, but nutritional status plays a significant role in patient outcomes, and these products may help alleviate deficiencies. For example, evidence indicates that vitamin D deficiency may be associated with a greater incidence of infection and severity of COVID-19, suggesting that vitamin D supplementation may hold prophylactic or therapeutic value. A growing number of scientific organizations are now considering recommending vitamin D supplementation to those at high risk of COVID-19. Because research in vitamin D and other nutraceuticals and supplements is preliminary, here we evaluate the extent to which these nutraceutical and dietary supplements hold potential in the COVID-19 crisis.IMPORTANCE Sales of dietary supplements and nutraceuticals have increased during the pandemic due to their perceived "immune-boosting" effects. However, little is known about the efficacy of these dietary supplements and nutraceuticals against the novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) or the disease that it causes, CoV disease 2019 (COVID-19). This review provides a critical overview of the potential prophylactic and therapeutic value of various dietary supplements and nutraceuticals from the evidence available to date. These include vitamin C, vitamin D, and zinc, which are often perceived by the public as treating respiratory infections or supporting immune health. Consumers need to be aware of misinformation and false promises surrounding some supplements, which may be subject to limited regulation by authorities. However, considerably more research is required to determine whether dietary supplements and nutraceuticals exhibit prophylactic and therapeutic value against SARS-CoV-2 infection and COVID-19. This review provides perspective on which nutraceuticals and supplements are involved in biological processes that are relevant to recovery from or prevention of COVID-19.

Enhanced alveo pulmonary deposition of nebulized ciclesonide for attenuating airways inflammations: a strategy to overcome metered dose inhaler drawbacks

Ciclesonide (CIC), an inhaled corticosteroid for bronchial asthma is currently available as metered dose inhaler (CIC–MDI) which possesses a major challenge in the management of the elderly, critically ill patients and children. In this work, nebulized CIC nano-structure lipid particles (CIC-NLPs) were prepared and evaluated for their deep pulmonary delivery and cytotoxicity to provide additional clinical benefits to patients in controlled manner and lower dose. The bio-efficacy following nebulization in ovalbumin (OVA) induced asthma Balb/c mice compared to commercial (CIC–MDI) was also assessed. The developed NLPs of 222.6 nm successfully entrapped CIC (entrapment efficiency 93.3%) and exhibited favorable aerosolization efficiency (mass median aerodynamic diameter (MMAD) 2.03 μm and fine particle fraction (FPF) of 84.51%) at lower impactor stages indicating deep lung deposition without imparting any cytotoxic effect up to a concentration of 100 μg/ml. The nebulization of 40 µg dose of the developed CIC-NLPs revealed significant therapeutic impact in the mitigation of the allergic airways inflammations when compared to 80 µg dose of the commercial CIC–MDI inhaler (Alvesco^®). Superior anti-inflammatory and antioxidative stress effects characterized by significant decrease (p< .0001) in inflammatory cytokines IL-4 and 13, serum IgE levels, malondialdehyde (MDA), nitric oxide (NO), TNF-α, and activated nuclear factor-κB (NF-κB) activity were obvious with concomitant increase in superoxide dismutase (SOD) activity. Histological examination with inhibition of inflammatory cell infiltration in the respiratory tract was correlated well with observed biochemical improvement.

Construction of mannose-modified polyethyleneimine-block-polycaprolactone cationic polymer micelles and its application in acute lung injury

This study evaluated the D-mannose modified polyethyleneimine-block-polycaprolactone biomacromolecule copolymer micelles (PCL-PEI-mannose) as a targeted delivery of the glucocorticoid dexamethasone (DXM) to lung inflammation tissues and enhances the vehicle for its anti-inflammatory effects. Dexamethasone was encapsulated in the hydrophobic core of cationic polymer micelles by solvent evaporation. The polymeric micelles exhibited sustained-release within 48 h, good blood compatibility, and colloidal stability in vitro. The cellular uptake of mannose-modified micelles was higher compared with the non-modified micelles. And drug-loaded targeted micelles could inhibit the production of inflammatory factors in activated RAW264.7 cells. The distribution results indicated that drug-loaded targeted micelles highly improved the lung targeting ability, reduced the wet/dry ratio of injured lung tissue, and relieved the lung inflammation, accompanied by the decrease of inflammatory cell infiltration, myeloperoxidase activity, and inflammatory mediator levels in bronchoalveolar lavage fluid. These findings suggested that PCL-PEI-mannose delivery system could facilitate the lung-specific delivery and inhibit the inflammatory response. Collectively, PCL-PEI-mannose polymer micelles could be used as a potential delivery system for the treatment of acute lung injury (ALI).

Dietary Supplements and Nutraceuticals Under Investigation for COVID-19 Prevention and Treatment

Coronavirus disease 2019 (COVID-19) has caused global disruption and a significant loss of life. Existing treatments that can be repurposed as prophylactic and therapeutic agents could reduce the pandemic's devastation. Emerging evidence of potential applications in other therapeutic contexts has led to the investigation of dietary supplements and nutraceuticals for COVID-19. Such products include vitamin C, vitamin D, omega 3 polyunsaturated fatty acids, probiotics, and zinc, all of which are currently under clinical investigation. In this review, we critically appraise the evidence surrounding dietary supplements and nutraceuticals for the prophylaxis and treatment of COVID-19. Overall, further study is required before evidence-based recommendations can be formulated, but nutritional status plays a significant role in patient outcomes, and these products could help alleviate deficiencies. For example, evidence indicates that vitamin D deficiency may be associated with greater incidence of infection and severity of COVID-19, suggesting that vitamin D supplementation may hold prophylactic or therapeutic value. A growing number of scientific organizations are now considering recommending vitamin D supplementation to those at high risk of COVID-19. Because research in vitamin D and other nutraceuticals and supplements is preliminary, here we evaluate the extent to which these nutraceutical and dietary supplements hold potential in the COVID-19 crisis.

Composition and Functionality of Lipid Emulsions in Parenteral Nutrition: Examining Evidence in Clinical Applications

Lipid emulsions (LEs), an integral component in parenteral nutrition (PN) feeding, have shifted from the primary aim of delivering non-protein calories and essential fatty acids to defined therapeutic outcomes such as reducing inflammation, and improving metabolic and clinical outcomes. Use of LEs in PN for surgical and critically ill patients is particularly well established, and there is enough literature assigning therapeutic and adverse effects to specific LEs. This narrative review contrarily puts into perspective the fatty acid compositional (FAC) nature of LE formulations, and discusses clinical applications and outcomes according to the biological function and structural functionality of fatty acids and co-factors such as phytosterols, α-tocopherol, emulsifiers and vitamin K. In addition to soybean oil-based LEs, this review covers clinical studies using the alternate LEs that incorporates physical mixtures combining medium- and long-chain triglycerides or structured triglycerides or the unusual olive oil or fish oil. The Jaded score was applied to assess the quality of these studies, and we report outcomes categorized as per immuno-inflammatory, nutritional, clinical, and cellular level FAC changes. It appears that the FAC nature of LEs is the primary determinant of desired clinical outcomes, and we conclude that one type of LE alone cannot be uniformly applied to patient care.

Preconditioning rats with three lipid emulsions prior to acute lung injury affects cytokine production and cell apoptosis in the lung and liver

BACKGROUND

Critically ill patients are at higher risk having acute lung injury (ALI) and more often in need of parenteral nutrition. We sought to study whether preconditioning with representative of lipid emulsions for one week could benefit rats from ALI.

METHODS

Using a lipopolysaccharide (LPS)-induced ALI rat model and techniques such as polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining.

RESULTS

PGE₂ production in the serum was highest in the LPS group, followed with Intralipid group, and the PGE₂ level of these two groups was significantly (P < 0.05) higher than the rest. Intralipid conditioning caused significantly less production of LTB₄ than the LPS, Clinoleic, or Omegaven group. In contrast to Intralipid, rats pretreated with Clinoleic or Omegaven significantly decreased their production of inflammatory mediators (IL-1 β, IL-6 and TNF-α), had less apoptosis in the lung tissues, and Omegaven greatly improved liver function upon lipopolysaccharide (LPS) challenge.

CONCLUSIONS

In an ALI setting, preconditioning with Omegaven or Clinoleic was better than Intralipid in decreasing the intensity of the cytokine storm and apoptosis caused by LPS challenge, and Omegaven in addition had the potential to improve liver function. The results from the present study set a basis for further investigation of the molecular mechanisms of ALI, including the up- and downstream pathways of proinflammatory factor production, in search of (small) molecules intervening with the pathogenesis of ALI in order to translate relevant research findings into clinical benefit for patients with ALI. The use of Omegaven or Clinoleic, particularly in patients with ALI, is still characterized by uncertainty due to a lack of relevant studies. Future investigations must specifically focus on the route of administration and mode of application (enteral vs. parenteral/bolus vs. continuous), determining an optimal dose of Omegaven or Clinoleic, and the defining the best timepoint(s) for administration. Critically ill patients are at higher risk having acute lung injury (ALI) and more often in need of parenteral nutrition. The effect of lipid emulsion via parenteral nutrition on liver function was first time evaluated in rats in an ALI setting. The comparison of three forms of lipid emulsion in a rat model of acute lung injury was first time studied. The fish oil-based lipid emulsion decrease in PGE 2 and increase in LTB 4 was first time reported.

ω-3 Fatty-Acid Enriched Parenteral Nutrition in Hospitalized Patients: Systematic Review With Meta-Analysis and Trial Sequential Analysis

This systematic review and meta-analysis investigated ω-3 fatty-acid enriched parenteral nutrition (PN) vs standard (non-ω-3 fatty-acid enriched) PN in adult hospitalized patients (PROSPERO 2018 CRD42018110179). We included 49 randomized controlled trials (RCTs) with intervention and control groups given ω-3 fatty acids and standard lipid emulsions, respectively, as part of PN covering ≥70% energy provision. The relative risk (RR) of infection (primary outcome; 24 RCTs) was 40% lower with ω-3 fatty-acid enriched PN than standard PN (RR 0.60, 95% confidence interval [CI] 0.49-0.72; P < 0.00001). Patients given ω-3 fatty-acid enriched PN had reduced mean length of intensive care unit (ICU) stay (10 RCTs; 1.95 days, 95% CI 0.42-3.49; P = 0.01) and reduced length of hospital stay (26 RCTs; 2.14 days, 95% CI 1.36-2.93; P < 0.00001). Risk of sepsis (9 RCTs) was reduced by 56% in those given ω-3 fatty-acid enriched PN (RR 0.44, 95% CI 0.28-0.70; P = 0.0004). Mortality rate (co-primary outcome; 20 RCTs) showed a nonsignificant 16% reduction (RR 0.84, 95% CI 0.65-1.07; P = 0.15) for the ω-3 fatty-acid enriched group. In summary, ω-3 fatty-acid enriched PN is beneficial, reducing risk of infection and sepsis by 40% and 56%, respectively, and length of both ICU and hospital stay by about 2 days. Provision of ω-3-enriched lipid emulsions should be preferred over standard lipid emulsions in patients with an indication for PN.

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.

Relationship between enteral nutrition and serum levels of inflammatory factors and cardiac function in elderly patients with heart failure

Objective

To investigate enteral nutrition’s effect on serum inflammatory factors and the cardiac function of malnourished elderly patients with heart failure.

Patients and methods

A total of 105 elderly patients with heart failure were randomly divided into 3 groups: Treatment Group A, Treatment Group B, and the Control Group (Group C), each group having 35 patients and being administered conventional heart failure treatment. Group A was treated with 500 mL·d⁻¹ of enteral nutrition for 1 month. Group B was given the same dose of enteral nutrition for 3 months. The Control Group was given free diet. Nutritional risk screening 2002 was used to assess the nutritional status before and after the treatment for each group. New York Heart Association status was recorded as were left ventricular ejection fraction, plasma B-type natriuretic peptide, inteleukin-6, C-reactive protein, and tumor necrosis factor-α.

Results

After the treatment, the body mass index, skinfold thickness of upper arm triceps, muscle circumference of the upper arm, upper arm muscle circumference, total protein, albumin, hemoglobin, and left ventricular ejection fraction in the treatment groups all increased, with relatively obvious relief of symptoms of heart failure. The levels of B-type natriuretic peptide, interleukin-6, tumor necrosis factor-α, and C-reactive protein all rose to different extents (P<0.05) and Treatment Group B showed more obvious improvement (P<0.01). Differences shown by the Control Group in each nutrition indicator, serum levels of inflammatory factors, and cardiac function had no statistical significance (P>0.05).

Conclusion

The use of enteral nutrition in conventional treatment of elderly patients with heart failure could improve not only patients’ nutritional status and cardiac function, but also their immune function, thus reducing the levels of inflammatory factors. The longer the treatment period is, the more obvious the improvement in patients’ cardiac function and inflammatory factors will be observed.

Pathophysiology and Management of Acute Respiratory Distress Syndrome in Children

Acute respiratory distress syndrome (ARDS) is a syndrome of noncardiogenic pulmonary edema and hypoxia that accompanies up to 30% of deaths in pediatric intensive care units. Pediatric ARDS (PARDS) is diagnosed by the presence of hypoxia, defined by oxygenation index or Pao₂/Fio₂ ratio cutoffs, and new chest infiltrate occurring within 7 days of a known insult. Hallmarks of ARDS include hypoxemia and decreased lung compliance, increased work of breathing, and impaired gas exchange. Mortality is often accompanied by multiple organ failure. Although many modalities to treat PARDS have been investigated, supportive therapies and lung protective ventilator support remain the mainstay.

Intravenous fish oil in critically ill and surgical patients - Historical remarks and critical appraisal

The purpose of this review is to explain the historical and clinical background for intravenous fish oil administration, to evaluate its results by using a product specific metaanalysis, and to stimulate further research in the immune-modulatory potential of fish oil. Concerning the immune-modulatory effects of fatty acids, a study revealed that ω-3 as well as ω-6 fatty acids would prolong transplant survival, and only a mixture with an ω-6:ω-3 ratio of 2.1:1 would give immune-neutral results. In 1998, the label of a newly registered fish oil emulsion also acknowledged this immune-neutral ratio in conjunction with ω-6 lipids. Also, two fish oil-supplemented fat emulsions, registered in 2004, used a similar ω-6:ω-3 ratio. Such an immune-neutral ω-6:ω-3 ratio denoted progress for most patients compared to pure ω-6 lipid emulsions. However, this immune-neutrality might on the other hand be responsible for the limited positive clinical results gained so far in critically ill and surgical patients where in most cases significance could only be shown for the pooled effect of numerous trials. Our product specific metaanalysis also did not reveal any differences, neither in infections rates nor in ICU or hospital length of stay. To evaluate the immune-modulatory effect of fish oil administered alone, new dose finding studies, reporting relevant clinical outcome parameters, are required. Precise mechanistic or physiological biomarkers for the indication of such a therapy should also be developed and validated.

The possible role of intravenous lipid emulsion in the treatment of chemical warfare agent poisoning

Organophosphates (OPs) are cholinesterase inhibitors that lead to a characteristic toxidrome of hypersecretion, miosis, dyspnea, respiratory insufficiency, convulsions and, without proper and early antidotal treatment, death. Most of these compounds are highly lipophilic. Sulfur mustard is a toxic lipophilic alkylating agent, exerting its damage through alkylation of cellular macromolecules (e.g., DNA, proteins) and intense activation of pro-inflammatory pathways. Currently approved antidotes against OPs include the peripheral anticholinergic drug atropine and an oxime that reactivates the inhibited cholinesterase. Benzodiazepines are used to stop organophosphate-induced seizures. Despite these approved drugs, efforts have been made to introduce other medical countermeasures in order to attenuate both the short-term and long-term clinical effects following exposure. Currently, there is no antidote against sulfur mustard poisoning. Intravenous lipid emulsions are used as a source of calories in parenteral nutrition. In recent years, efficacy of lipid emulsions has been shown in the treatment of poisoning by fat-soluble compounds in animal models as well as clinically in humans. In this review we discuss the usefulness of intravenous lipid emulsions as an adjunct to the in-hospital treatment of chemical warfare agent poisoning.

Lipid emulsions for parenteral nutrition in critical illness

Critical illness is a life-threatening multisystem process that can result in significant morbidity and mortality. In most patients, critical illness is preceded by a physiological deterioration, characterized by a catabolic state and intense metabolic changes, resulting in malnutrition and impaired immune functions. In this context, parenteral lipid emulsions may modulate inflammatory and immune reactions, depending on their fatty acid composition. These effects appear to be based on complex modifications in the composition and structure of cell membranes, through eicosanoid and cytokine synthesis and by modulation of gene expression. The pathophysiological mechanisms underlying these fatty acid-induced immune function alterations in critical ill patients are however complex and partially understood. Indeed, despite a very abundant literature, experimental and clinical data remain contradictory. The optimization of lipid emulsion composition thus represents a major challenge for clinical medicine, to adequately modulate the inflammatory pathways. In the present review, we first address the metabolic response to aggression, the effects of parenteral lipid emulsions on inflammation and immunity, and finally the controversial place of these lipid emulsions during critical illness. The analysis furthermore highlights the pathophysiological mechanisms underlying the differential effects of lipid emulsions and their potential for improving the handling of critically ill patients.

The Role of Omega-3 Polyunsaturated Fatty Acids in the Treatment of Patients with Acute Respiratory Distress Syndrome: A Clinical Review

Acute respiratory distress syndrome (ARDS) is defined as the acute onset of noncardiogenic edema and subsequent gas-exchange impairment due to a severe inflammatory process. Recent report on the prognostic value of eicosanoids in patients with ARDS suggests that modulating the inflammatory response through the use of polyunsaturated fatty acids may be a useful strategy for ARDS treatment. The use of enteral diets enriched with eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA) has reported promising results, showing an improvement in respiratory variables and haemodynamics. However, the interpretation of the studies is limited by their heterogeneity and methodology and the effect of ω-3 fatty acid-enriched lipid emulsion or enteral diets on patients with ARDS remains unclear. Therefore, the routine use of ω-3 fatty acid-enriched nutrition cannot be recommended and further large, homogeneous, and high-quality clinical trials need to be conducted to clarify the effectiveness of ω-3 polyunsaturated fatty acids.

Nonpulmonary treatments for pediatric acute respiratory distress syndrome: proceedings from the Pediatric Acute Lung Injury Consensus Conference

OBJECTIVE

To describe the recommendations from the Pediatric Acute Lung Injury Consensus Conference on nonpulmonary treatments in pediatric acute respiratory distress syndrome.

DESIGN

Consensus conference of experts in pediatric acute lung injury.

METHODS

A panel of 27 experts met over the course of 2 years to develop a taxonomy to define pediatric acute respiratory distress syndrome and to make recommendations regarding treatment and research priorities. The nonpulmonary subgroup comprised three experts. When published data were lacking, a modified Delphi approach emphasizing strong professional agreement was utilized.

RESULTS

The Pediatric Acute Lung Injury Consensus Conference experts developed and voted on a total of 151 recommendations addressing the topics related to pediatric acute respiratory distress syndrome, 30 of which related to nonpulmonary treatment. All 30 recommendations had strong agreement. Patients with pediatric acute respiratory distress syndrome should receive 1) minimal yet effective targeted sedation to facilitate mechanical ventilation; 2) neuromuscular blockade, if sedation alone is inadequate to achieve effective mechanical ventilation; 3) a nutrition plan to facilitate their recovery, maintain their growth, and meet their metabolic needs; 4) goal-directed fluid management to maintain adequate intravascular volume, end-organ perfusion, and optimal delivery of oxygen; and 5) goal-directed RBC transfusion to maintain adequate oxygen delivery. Future clinical trials in pediatric acute respiratory distress syndrome should report sedation, neuromuscular blockade, nutrition, fluid management, and transfusion exposures to allow comparison across studies.

CONCLUSIONS

The Consensus Conference developed pediatric-specific definitions for pediatric acute respiratory distress syndrome and recommendations regarding treatment and future research priorities. These recommendations for nonpulmonary treatment in pediatric acute respiratory distress syndrome are intended to promote optimization and consistency of care for patients with pediatric acute respiratory distress syndrome and identify areas of uncertainty requiring further investigation.

Prospective double-blind randomized study on the efficacy and safety of an n-3 fatty acid enriched intravenous fat emulsion in postsurgical gastric and colorectal cancer patients

Background

A lipid emulsion composed of soybean oil (long-chain triglycerides, LCT), medium-chain triglycerides (MCT) and n-3 poly-unsaturated fatty acids (PUFAs) was evaluated for immune-modulation efficacy, safety, and tolerance in patients undergoing major surgery for gastric and colorectal cancer.

Methods

In a prospective, randomized, double-blind study, 99 patients with gastric and colorectal cancer receiving elective surgery were recruited and randomly assigned to either the study group, receiving the n-3 PUFAs enriched intravenous fat emulsion (IVFE), or the control group, receiving a lipid emulsion comprised of soybean oil and MCTs (0.8 – 1.5 g · kg^-1 · day^-1) as part of total parenteral nutrition (TPN) regimen from surgery (day -1) up to post-operative day 7. Safety and efficacy parameters were assessed on day -1 and post-operative visits on day 1, 3, and 7. Adverse events were documented daily and compared between the groups.

Results

Pro-inflammatory markers, laboratory parameters, and adverse events did not differ prominently between the 2 groups, with the exception of net changes (day 7 minus day -1) of free fatty acids (FFAs), triglyceride, and high-density lipoprotein (HDL). Net decrease of FFAs was remarkably higher in the study group, while the net increase of triglyceride and decrease of HDL was significantly lower.

Conclusions

The n-3 PUFA-enriched IVFE showed improvements in lipid metabolism. In respect of efficacy, safety and tolerance both IVFE were comparable. In patients with severe stress, there is an inflammation-attenuating effect of n-3 PUFAs. Further, adequately powered clinical trials will be necessary to address this question in postsurgical GI cancer patients.

Trial registration

US ClinicalTrials.gov NCT00798447.

Is omega-3 fatty acids enriched nutrition support safe for critical ill patients? A systematic review and meta-analysis

OBJECTIVE

To systematically review the effects of omega-3 poly unsaturated fatty acids (FA) enriched nutrition support on the mortality of critically illness patients.

METHODS

Databases of Medline, ISI, Cochrane Library, and Chinese Biomedicine Database were searched and randomized controlled trials (RCTs) were identified. We enrolled RCTs that compared fish oil enriched nutrition support and standard nutrition support. Major outcome is mortality. Methodological quality assessment was conducted based on Modified Jadad's score scale. For control heterogeneity, we developed a method that integrated I2 test, nutritional support route subgroup analysis and clinical condition of severity. RevMan 5.0 software (The Nordic Cochrane Centre, Copenhagen, Denmark) was used for meta-analysis.

RESULTS

Twelve trials involving 1208 patients that met all the inclusion criteria. Heterogeneity existed between the trials. A random model was used, there was no significant effect on mortality RR, 0.82, 95% confidence interval (CI) (0.62, 1.09), p = 0.18. Knowing that the route of fish oil administration may affect heterogeneity, we categorized the trials into two sub-groups: parenteral administration (PN) of omega-3 and enteral administration (EN) of omega-3. Six trials administered omega-3 FA through PN. Pooled results indicated that omega-3 FA had no significant effect on mortality, RR 0.76, 95% CI (0.52, 1.10), p = 0.15. Six trials used omega-3 fatty acids enriched EN. After excluded one trial that was identified as source of heterogeneity, pooled data indicated omega-3 FA enriched EN significant reduce mortality, RR=0.69, 95% CI [0.53, 0.91] (p = 0.007).

CONCLUSION

Omega-3 FA enriched nutrition support is safe. Due to the limited sample size of the included trials, further large-scale RCTs are needed.

Lipids for intravenous nutrition in hospitalised adult patients: a multiple choice of options

Lipids used in parenteral nutrition provide energy, building blocks and essential fatty acids. Traditionally, these lipids have been based on n-6 PUFA-rich vegetable oils particularly soyabean oil. This may not be optimal because soyabean oil may present an excessive supply of linoleic acid. Alternatives to use of soyabean oil include its partial replacement by medium-chain TAG, olive oil or fish oil, either alone or in combination. Lipid emulsions containing these alternatives are well tolerated without adverse effects in a wide range of hospitalised adult patients. Lipid emulsions that include fish oil have been used in parenteral nutrition in adult patients' post-surgery (mainly gastrointestinal). This has been associated with alterations in patterns of inflammatory mediators and in immune function and, in some studies, a reduction in length of intensive care unit and hospital stay. These benefits are emphasised through recent meta-analyses. Perioperative administration of fish oil may be superior to post-operative administration. Parenteral fish oil has been used in critically ill adults. Here, the influence on inflammatory processes, immune function and clinical endpoints is not clear, since there are too few studies and those that are available report contradictory findings. However, some studies found reduced inflammation, improved gas exchange and shorter length of hospital stay in critically ill patients if they receive fish oil. More and better trials are needed in patient groups in which parenteral nutrition is used and where fish oil may offer benefits.

Respiratory hospitalisation of infants supplemented with docosahexaenoic acid as preterm neonates

AIM

To determine the effect of neonatal docosahexaenoic acid (DHA) supplementation in preterm infants on later respiratory-related hospitalisations.

METHODS

We enrolled 657 infants in a multicentre, randomised, controlled trial designed to study the long-term efficacy of higher dose dietary DHA in infants born <33 weeks' gestation. Treatment was with high DHA (∼1%) compared with standard DHA (∼0.3%) in breast milk or formula, given from the first week of life to term equivalent. Parent-reported hospital admissions to 18 months corrected age were recorded. The proportion of children hospitalised for lower respiratory tract (LRT) conditions and the mean number of hospitalisations per infant were determined.

RESULTS

Twenty-three per cent (154/657) of infants were hospitalised for LRT conditions. Seventy-three per cent (173/238) of admissions were for bronchiolitis. There was no significant effect of higher DHA on the proportion of infants admitted for LRT conditions (high DHA 22% vs. standard DHA 25%, adjusted relative risk 0.92, 95% confidence interval (CI) 0.68-1.24, P = 0.57) or in the mean number of admissions per infant (high DHA 0.34, standard DHA 0.38, adjusted ratio of means 0.91, 95% CI 0.63-1.32, P = 0.62). The sexes responded differently to treatment (interaction P = 0.046), with reduced admissions in boys given high DHA, but this was not statistically significant (high DHA 19%, standard DHA 28%, adjusted relative risk 0.69, 95% CI 0.46-1.04, P = 0.08).

CONCLUSIONS

Hospitalisation for LRT problems in the first 18 months for preterm infants was not reduced by neonatal supplementation with 1% DHA.

Nutritional immunomodulation in critically ill children with acute lung injury: feasibility and impact on circulating biomarkers

OBJECTIVE

Respiratory failure caused by acute lung injury or acute respiratory distress syndrome is associated with significant morbidity in children. Enteral nutrition enriched with eicosapentaenoic acid, γ-linolenic acid and antioxidants (eicosapentaenoic acid + γ-linolenic acid) can safely modulate plasma phospholipid fatty acid profiles, reduce inflammation, and improve clinical outcomes in adults. There is little information regarding the use of enteral eicosapentaenoic acid + γ-linolenic acid to modulate plasma phospholipid fatty acid profiles in children. We sought to determine if continuous feeding of enteral nutrition containing eicosapentaenoic acid, γ-linolenic acid, and antioxidants was feasible in critically ill children with acute lung injury or acute respiratory distress syndrome. We further evaluated the impact of such an approach on the alteration of plasma phospholipid fatty acid concentrations.

DESIGN

Prospective, blinded, randomized, controlled, multicenter trial.

SETTING

PICU.

PATIENTS

Twenty-six critically ill children (age 6.2 ± 0.9 yr, PaO2/FIO2 185 ± 15) with the diagnosis of acute lung injury or acute respiratory distress syndrome.

INTERVENTIONS

Mechanically ventilated children received either eicosapentaenoic acid + γ-linolenic acid or a standard pediatric enteral formula. Clinical, biochemical, plasma fatty acid, and safety data were assessed at baseline, study days 4 and 7.

MEASUREMENTS AND MAIN RESULTS

At baseline, there were no significant differences in the two study groups. Both groups met enteral feeding goals within 30 hrs and had similar caloric delivery. There were no differences in formula tolerance as measured by serum chemistries, liver and renal function, and hematology studies after 7 days of feeding either eicosapentaenoic acid + γ-linolenic acid or pediatric enteral formula. On study day 4 and 7, plasma phospholipid fatty acid profiles in the eicosapentaenoic acid + γ-linolenic acid group showed a significant increase in anti-inflammatory circulating markers.

CONCLUSIONS

Providing enteral nutrition with eicosapentaenoic acid + γ-linolenic acid to critically ill children with lung injury was feasible and caloric goals were met within 30 hrs. This feeding protocol effectively modulated plasma phospholipid fatty acid concentrations to reflect an anti-inflammatory profile. This study provides data to inform future outcome studies using enteral eicosapentaenoic acid + γ-linolenic acid in children with lung injury.

Parenteral omega-3 fatty acids: pouring oil on troubled waters?

A meta-analysis of parenteral fish oil in 23 studies in intensive care unit (ICU) and non-ICU patients reported a reduced infection rate (significant in ICU patients) and shorter lengths of ICU and hospital stays (both non-ICU and ICU patients). Parenteral fish oil reduced inflammation and improved oxygenation index and liver function. The findings of the meta-analysis are discussed in this report.

n-3 fatty acid-enriched parenteral nutrition regimens in elective surgical and ICU patients: a meta-analysis

INTRODUCTION

Previous studies and a meta-analysis in surgical patients indicate that supplementing parenteral nutrition regimens with n-3 polyunsaturated fatty acids (PUFAs), in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is associated with improved laboratory and clinical outcomes in the setting of hyper-inflammatory conditions. Refined or synthetic fish oils are commonly used as a source of EPA and DHA. The objective of the present meta-analysis was to evaluate n-3 PUFA-enriched parenteral nutrition regimens in elective surgical and intensive care unit (ICU) patients.

METHODS

Medline was searched for randomized controlled trials comparing n-3 PUFA-enriched lipid emulsions with standard non-enriched lipid emulsions (i.e. soybean oil, MCT/LCT or olive/soybean oil emulsions) in surgical and ICU patients receiving parenteral nutrition. Extracted data were pooled by means of both random and fixed effects models, and subgroup analyses were carried forward to compare findings in ICU versus non-ICU patients.

RESULTS

A total of 23 studies (n = 1502 patients: n = 762 admitted to the ICU) were included. No statistically significant difference in mortality rate was found between patients receiving n-3 PUFA-enriched lipid emulsions and those receiving standard lipid emulsions (RR = 0.89; 0.59, 1.33), possibly reflecting a relatively low underlying mortality risk. However, n-3 PUFA-enriched emulsions are associated with a statistically and clinically significant reduction in the infection rate (RR = 0.61; 0.45, 0.84) and the lengths of stay, both in the ICU (-1.92; -3.27, -0.58) and in hospital overall (-3.29; -5.13, -1.45). Other beneficial effects included reduced markers of inflammation, improved lung gas exchange, liver function, antioxidant status and fatty acid composition of plasma phospholipids, and a trend towards less impairment of kidney function.

CONCLUSIONS

These results confirm and extend previous findings, indicating that n-3 PUFAs-enriched parenteral nutrition regimens are safe and effective in reducing the infection rate and hospital/ICU stay in surgical and ICU patients.

Omics approaches in cystic fibrosis research: a focus on oxylipin profiling in airway secretions

Cystic fibrosis (CF) is associated with abnormal lipid metabolism, intense respiratory tract (RT) infection, and inflammation, eventually resulting in lung tissue destruction and respiratory failure. The CF RT inflammatory milieu, as reflected by airway secretions, includes a complex array of inflammatory mediators, bacterial products, and host secretions. It is dominated by neutrophils and their proteolytic and oxidative products and includes a wide spectrum of bioactive lipids produced by both host and presumably microbial metabolic pathways. The fairly recent advent of "omics" technologies has greatly increased capabilities of further interrogating this easily obtainable RT compartment that represents the apical culture media of the underlying RT epithelial cells. This paper discusses issues related to the study of CF omics with a focus on the profiling of CF RT oxylipins. Challenges in their identification/quantitation in RT fluids, their pathways of origin, and their potential utility for understanding CF RT inflammatory and oxidative processes are highlighted. Finally, the utility of oxylipin metabolic profiling in directing optimal therapeutic approaches and determining the efficacy of various interventions is discussed.

Increased EPA levels in serum phospholipids of humans after four weeks daily ingestion of one portion chicken fed linseed and rapeseed oil

Since the amounts of arachidonic acid (AA) and EPA in food may have implications for human health, we investigated whether a small change in chicken feed influenced the blood lipid concentration in humans ingesting the chicken. Forty-six young healthy volunteers (age 20-29) were randomly allocated into two groups in a double-blind dietary intervention trial, involving ingestion of about 160 g chicken meat per day for 4 weeks. The ingested meat was either from chickens given a feed concentrate resembling the commercial chicken feed, containing 4% soybean oil (SO), or the meat was from chickens given a feed where the soybean oil had been replaced by 2% rapeseed oil plus 2% linseed oil (RLO).Serum total cholesterol, LDL and HDL cholesterol, triacylglycerols, serum phospholipid fatty acid concentration, blood pressure, body weight and C-reactive protein were determined at baseline and post-intervention. In subjects consuming chicken meat from the RLO group there was a significantly (p < 0.001) increased concentration of EPA in serum phospholipids, and a reduced ratio between AA and EPA. The participants that had a low% of EPA + DHA in serum phospholipids (less than 4.6%), all increased their% of EPA + DHA after the four week intervention period when consuming the RLO chicken. No significant response differences in cholesterol, triacylglycerol, C-reactive protein, body weight or blood pressure were observed between the groups. This trial demonstrates that a simple change in chicken feed can have beneficial effects on amount of EPA and the AA/EPA ratio in human serum phospholipids.