Alternative lipid emulsions in the critically ill: a systematic review of the evidence

Comparison of catheter-related bloodstream infection rates in pediatric patients receiving parenteral nutrition with soybean oil-based intravenous fat emulsion versus a mixed oil fat emulsion

STUDY OBJECTIVE

To compare rates of catheter-related bloodstream infections (CR-BSI) in pediatric patients who received parenteral nutrition (PN) with either soybean oil-based intravenous fat emulsion (SO-IFE) or mixed oil-IFE (MO-IFE). We hypothesized that the use of MO-IFE would be independently associated with reduced infection rates compared with SO-IFE.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral children's hospital and its associated gastrointestinal rehabilitation clinic (01 January, 2015-31 July, 2019).

PATIENTS

Days of IFE exposure were counted for patients aged <18 years on IFE initiated during the review period, who had a central venous catheter (CVC) placed for PN administration, received IFE at least three times weekly, and for at least 7 days.

MEASUREMENTS

The primary outcome included total and categorical CR-BSI rates expressed as the average with standard error (SE) number of infections per 1000 fat emulsion days. The following categories were specified: Candida albicans, non-albicans Candida spp., coagulase-negative Staphylococcus (CoNS), Enterobacterales, methicillin-resistant S. aureus, methicillin-susceptible S. aureus, and Pseudomonadales. Average infection rate comparisons were quantified as incidence rate ratios (IRR) using generalized linear mixed modeling with a Poisson distribution.

MAIN RESULTS

Seven hundred and forty-three SO-IFE and 450 MO-IFE exposures were reviewed from 1131 patients, totaling 37,599 and 19,796 days of therapy, respectively. From those found significantly different, the average rate of infections with CoNS was 3.58 (SE 0.5)/1000 days of SO-IFE and 1.39 (SE 0.45)/1000 days of MO-IFE (IRR [95% confidence interval, CI]: 0.27 [0.16-0.46]; p < 0.01). Total average rates of infection were 7.33 (SE 0.76)/1000 days of SO-IFE and 4.52 (SE 0.75)/1000 days of MO-IFE (IRR [95% CI]: 0.60 [0.44-0.81]; p < 0.01). Other factors associated with higher infection rates include female gender, neonatal age, and inpatient-only IFE exposure.

CONCLUSIONS

Receipt of MO-IFE was associated with lower rates of CoNS and total CR-BSIs compared with SO-IFE in pediatric patients. These findings could have major implications on IFE selection for pediatric patients receiving PN.

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet (MedD). In this narrative review, we synthesize and illustrate the various characteristics and clinical applications of EVOO and its components—such as oleic acid, hydroxytyrosol, and oleuropein—in the field of clinical nutrition and dietetics. The evidence is split into diet therapy, oleic acid-based enteral nutrition formulations and oral supplementation formulations, oleic acid-based parenteral nutrition, and nutraceutical supplementation of minor components of EVOO. EVOO has diverse beneficial health properties, and current evidence supports the use of whole EVOO in diet therapy and the supplementation of its minor components to improve cardiovascular health, lipoprotein metabolism, and diabetes mellitus in clinical nutrition. Nevertheless, more intervention studies in humans are needed to chisel specific recommendations for its therapeutic use through different formulations in other specific diseases and clinical populations.

Association Between Lack of Blinding and Mortality Results in Critical Care Randomized Controlled Trials: A Meta-Epidemiological Study

OBJECTIVES

To investigate whether intervention effect estimates for mortality differ between blinded and nonblinded randomized controlled trials conducted in critical care. We used a meta-epidemiological approach, comparing effect estimates between blinded and nonblinded randomized controlled trials for the same research question.

DATA SOURCES

Systematic reviews and meta-analyses of randomized controlled trials evaluating a therapeutic intervention on mortality in critical care, published between January 2009 and March 2019 in high impact factor general medical or critical care journals and by Cochrane.

DATA EXTRACTION

For each randomized controlled trial included in eligible meta-analyses, we evaluated whether the trial was blinded (i.e., double-blinded and/or reporting adequate methods) or not (i.e., open-label, single-blinded, or unclear). We collected risk of bias evaluated by the review authors and extracted trial results.

DATA SYNTHESIS

Within each meta-analysis, we compared intervention effect estimates between blinded and nonblinded randomized controlled trials by using a ratio of odds ratio (< 1 indicates larger estimates in nonblinded than blinded randomized controlled trials). We then combined ratio of odds ratios across meta-analyses to obtain the average relative difference between nonblinded and blinded trials. Among 467 randomized controlled trials included in 36 meta-analyses, 267 (57%) were considered blinded and 200 (43%) nonblinded. Intervention effect estimates were statistically significantly larger in nonblinded than blinded trials (combined ratio of odds ratio, 0.91; 95% CI, 0.84-0.99). We found no heterogeneity across meta-analyses (p = 0.72; I2 = 0%; τ2 = 0). Sensitivity analyses adjusting the main analysis on risk of bias items yielded consistent results.

CONCLUSIONS

Intervention effect estimates of mortality were slightly larger in nonblinded than blinded randomized controlled trials conducted in critical care, but confounding cannot be excluded. Blinding of both patients and personnel is important to consider when possible in critical care trials, even when evaluating mortality.

Phytosterolaemia associated with parenteral nutrition administration in adult patients

Vegetable lipid emulsions (LE) contain non-declared phytosterols (PS). We aimed to determine PS content depending on the brand and LE batch, and in adult hospitalised patients treated with parenteral nutrition (PN), to establish the association between plasma and administered PS. Part I was the LE study: totals and fractions of PS in three to four non-consecutive batches from six LE were analysed. Part II was the patient study: patients with at least 7 previous days of PN with 0·8 g/kg per d of an olive/soyabean (O/S) LE were randomised (day 0) 1:1 to O/S or 100 % fish oil (FO) at a dose of 0·4 g/kg per d for 7 d (day 7). Plasma PS, its fractions, total cholesterol on days 0 and 7, their clearance and their association with PS administered by LE were studied. In part I, LE study: differences were found in the total PS, their fractions and cholesterol among different LE brands and batches. Exclusive soyabean LE had the highest content of PS (422·36 (sd 130·46) μg/ml). In part II, patient study: nineteen patients were included. In the O/S group, PS levels were maintained (1·11 (sd 6·98) μg/ml) from day 0 to 7, while in the FO group, significant decreases were seen in total PS (-6·21 (sd 4·73) μg/ml) and their fractions, except for campesterol and stigmasterol. Plasma PS on day 7 were significantly associated with PS administered (R2 0·443). PS content in different LE brands had great variability. PS administered during PN resulted in accumulation and could be prevented with the exclusive administration of FO LE.

[Effectiveness and safety of two lipid emulsions for parenteral nutrition in postsurgical critically ill patients: Clinoleic® versus SMOFlipid®]

Introduction

Introduction: a lipid emulsion (LE) may result in different immunomodulatory effects depending on its fatty acid composition. LEs enriched with fish oil and those based on olive oil (OOBE) have shown advantages over those derived from soybean oil, although very few studies have compared these with each other, and none was performed in critically ill surgical patients. Objectives: to demonstrate non-inferiority for the therapeutic efficacy of SMOFlipid® (enriched with fish oil) versus Clinoleic® (OOBE) in relation to the occurrence of nosocomial infection and other evolutionary parameters. To demonstrate non-inferiority in the safety profile of SMOFlipid® versus Clinoleic® in terms of mortality and adverse events. Material and method: a phase-III, non-inferiority clinical trial performed in critically ill postsurgical patients. The subjects were randomized to receive SMOFlipid® or Clinoleic®. For comparison of qualitative variables case frequencies and percentages were obtained using the Chi-squared test or Fisher's exact test. Means were compared between groups using Student's t-test. A p-value lower than 0.05 was considered statistically significant. The Farrington-Manning, Miettinen-Nurminen, and Gart-Nam tests were applied in the main non-inferiority analysis of the primary endpoint. Results: during de inclusion period 73 patients were selected, 37 of whom received Clinoleic® and 36 SMOFlipid®. Regarding the variable "decrease in nosocomial infections", SMOFlipid® proved to be non-inferior to Clinoleic®. Regarding the main variable "mortality", SMOFlipid® proved to be non-inferior to Clinoleic®. There were no statistically significant differences in the occurrence of adverse effects either. Conclusions: in our study, SMOFlipid® proved to be non-inferior to Clinoleic® in terms of efficacy and safety.

Effect of alternative intravenous lipid emulsion in clinical outcome in non-critically ill patients

INTRODUCTION

Most studies on alternative intravenous lipid emulsion (IVLE) versus conventional IVLE have been conducted in the critically ill patients. The benefits of alternative IVLE in non-critically ill patients is uncertain. We aim to determine clinical outcome difference between alternative IVLE versus conventional IVLE in non-critically ill patients.

METHOD

All patients on parenteral nutrition (PN) from July 2007 to September 2010 were identified. Patients were stratified into two groups: conventional IVLE (soybean oil-based) and alternative IVLEs, namely MCT oil-based, olive oil-based and fish oil-containing IVLE.

RESULT

Three hundred and eighty-eight patients were included in the study. Ninety-one patients received soybean-based IVLE, 59 patients received MCT oil-based IVLE, 141 patients received olive oil-based IVLE and 97 patients received fish oil-containing IVLE. Adjusting the effect of baseline covariates in separate multiple linear/logistic regression models, there were no differences in mortality, readmission, length of stay and infection between conventional IVLE group and alternative IVLEs group, the adjusted p-value was 0.64, 0.06, 0.36 and 0.18 respectively. However, there was a significant change in day 5 CRP between these two groups (8.43 g/L (SD 112.2) vs -41.2 (SD 106.4); adjusted p-value = 0.01). There was no difference in day 5 albumin between these two group (-1.03 (SD 5.1) vs -0.1 (SD 5.3); adjusted p-value = 0.08).

CONCLUSION

Our study showed that pertinent clinical outcomes in non-critically ill patients who received either conventional IVLE or alternative IVLEs were the same. However, there was significant reduction in day-5 CRP in alternative IVLE compared to conventional IVLE.

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.

Intravenous n-3 fatty acids in the critically ill

PURPOSE OF REVIEW

Lipid emulsions are an integral part of parenteral nutrition. Enteral nutrition is the preferred route to feed critically ill patients and parenteral nutrition is used in case of contraindications or when enteral nutrition does not reach the nutritional goals. n-3 Lipids are included into some newer lipid emulsions including fish oil or may be added by a fish oil-based lipid emulsion to lipid emulsion without fish oil. This review focuses on recent clinical trials, metaanalyses, and guidelines of parenteral nutrition with n-3 lipids in critically ill patients.

RECENT FINDINGS

Two single-center studies report a mortality benefit of adding fish oil-based lipid emulsions to the parenteral nutrition. Metaanalyses performed without these two studies had demonstrated beneficial effects of n-3 lipids regarding infections, length of stay, and time of mechanical ventilation but not on mortality. However, all metaanalyses judged the database derived from the underlying studies as not sufficient for a firm recommendation. Consecutively, guidelines and expert groups issue very cautious recommendations for the use of n-3 lipids in parenteral nutrition.

SUMMARY

Beneficial effects of n-3 lipids in trials and metaanalyses became available; however, high-quality multicenter randomized controlled trials are needed before more endorsing recommendation will be available.

ESPEN guideline on clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous guidelines to provide best medical nutritional therapy to critically ill patients have been updated. These guidelines define who are the patients at risk, how to assess nutritional status of an ICU patient, how to define the amount of energy to provide, the route to choose and how to adapt according to various clinical conditions. When to start and how to progress in the administration of adequate provision of nutrients is also described. The best determination of amount and nature of carbohydrates, fat and protein are suggested. Special attention is given to glutamine and omega-3 fatty acids. Particular conditions frequently observed in intensive care such as patients with dysphagia, frail patients, multiple trauma patients, abdominal surgery, sepsis, and obesity are discussed to guide the practitioner toward the best evidence based therapy. Monitoring of this nutritional therapy is discussed in a separate document.

Can Specialized Pro-resolving Mediators Deliver Benefit Originally Expected from Fish Oil?

PURPOSE OF THE REVIEW

Fish oil (FO) supplementation has historically been used by individuals suffering from cardiovascular disease and other inflammatory processes. However, a meta-analysis of several large randomized control trials (RCTs) suggested FO conferred no benefit in reducing cardiovascular risk. Skeptics surmised that the lack of benefit was related to FO dose or drug interactions; therefore, the widely accepted practice of FO consumption was brought into question.

RECENT FINDINGS

Thereafter, Serhan et al. identified specialized pro-resolving mediators (SPMs) to be one of the bioactive components and mechanisms of action of FO. SPMs are thought to enhance resolution of inflammation, as opposed to classic anti-inflammatory agents which inhibit inflammatory pathways. Numerous diseases, including persistent Inflammation, immunosuppression, and catabolic syndrome (PICS), are rooted in a burden of chronic inflammation. SPMs are gaining traction as potential therapeutic agents used to resolve inflammation in cardiovascular disorders, inflammatory bowel disease, sepsis, pancreatitis, and acute respiratory distress syndrome (ARDS). This narrative reviews the history of FO and the various studies that made the health benefits of FO inconclusive, as well as an overview of SPMs and their use in specific disease states.

Biological and Clinical Aspects of an Olive Oil-Based Lipid Emulsion-A Review

Intravenous lipid emulsions (ILEs) have been an integral component of parenteral nutrition for more than 50 years. Numerous formulations are available and are based on vegetable (soybean, olive, coconut) and animal (fish) oils. Therefore, each of these formulations has a unique fatty acid composition that offers both benefits and limitations. As clinical experience and our understanding of the effects of fatty acids on various physiological processes has grown, there is evidence to suggest that some ILEs may have benefits compared with others. Current evidence suggests that olive oil-based ILE may preserve immune, hepatobiliary, and endothelial cell function, and may reduce lipid peroxidation and plasma lipid levels. There is good evidence from a large randomized controlled study to support a benefit of olive oil-based ILE over soybean oil-based ILE on reducing infections in critically ill patients. At present there is limited evidence to demonstrate a benefit of olive oil-based ILE over other ILEs on glucose metabolism, and few data exist to demonstrate a benefit on clinical outcomes such as hospital or intensive care unit stay, duration of mechanical ventilation, or mortality. We review the current research and clinical evidence supporting the potential positive biological and clinical aspects of olive oil-based ILE and conclude that olive oil-based ILE is well tolerated and provides effective nutritional support to various PN-requiring patient populations. Olive oil-based ILE appears to support the innate immune system, is associated with fewer infections, induces less lipid peroxidation, and is not associated with increased hepatobiliary or lipid disturbances. These data would suggest that olive oil-based ILE is a valuable option in various PN-requiring patient populations.

Olive Oil and Soybean Oil Based Intravenous Lipid Emulsions, Liver Biochemistry and Clinical Outcomes

Intravenous lipid emulsions are an essential component of parenteral nutrition (PN). Omega-6 reducing strategies may improve outcomes, including reduced PN associated liver disease, however evidence to support this recommendation is insufficient. The primary objective was to compare serum alkaline phosphatase (ALP), among patients provided with either soybean oil (Intralipid) or predominantly olive oil (Clinoleic) lipid emulsions. In this quasi-experimental study, we reviewed the medical records of surgical and medical adult patients who received lipid emulsions for at least seven consecutive days. Among the 206 patients (110—Intralipid, 96—Clinoleic) there was no significant difference in ALP and remaining liver function tests within 2 weeks of PN therapy initiation between groups, even after control for lipid doses. Macronutrient dosing was similar. Triglyceride level was higher by 0.7 mmol/L in the Clinoleic group; confidence interval 0.21 to 1.1; p = 0.004. The 30-day mortality, length of hospital stay, and proportion of patients admitted to intensive care were not significantly different. The Clinoleic group had a higher infection rate (36% vs. 22%, p = 0.031) and longer intensive care stays (p = 0.045). Well-designed randomized clinical trials comparing these lipid emulsions are necessary to confirm Intralipid superiority over Clinoleic in relation to infections and serum triglycerides.

Intravenous lipid emulsions in the critically ill: an update

PURPOSE OF REVIEW

Purpose of the review is to summarize recent research addressing the role of intravenous lipid emulsions (IVLEs) in the critically ill.

RECENT FINDINGS

Soybean oil-based IVLEs, which are high in the omega-6 polyunsaturated fatty acids, have been largely used in parenteral nutrition over the last several decades. However, it is now generally accepted that the higher content of phytosterols and polyunsaturated fatty acids in soybean oil IVLE may adversely affect the immunological and inflammatory status of the critically ill. In the last few years, alternative IVLEs with lower soybean oil content have been associated with important improvements in clinical outcomes, such as mortality, mechanical ventilation days, and ICU length of stay. Olive oil and fish oil IVLEs have been reported to reduce the incidence of infections, with no clear benefits in other clinical outcomes. Despite the promising results with these new parenteral nutrition strategies, the optimum composition, dosage and indication for alternative IVLEs still remain controversial. Nevertheless, according to current knowledge alternative IVLEs may be associated with improved clinical outcomes and should be considered in critically ill patients requiring parenteral nutrition.

SUMMARY

There is a growing body of evidence suggesting that improved clinical outcomes can be achieved with selective use of alternative IVLEs in parenteral nutrition regimens for the critically ill. More high quality trials are needed, to better evaluate the efficacy of alternative IVLEs.

The science and art of pediatric critical care nutrition

PURPOSE OF REVIEW

Nutritional status and nutrient delivery during critical illness impact clinical outcomes. We have reviewed recent studies that may guide best practices regarding nutrition therapy in critically ill children.

RECENT FINDINGS

Malnutrition is prevalent in the pediatric ICU population, and is associated with worse outcomes. Nutrition support teams, dedicated dietitians, and educational programs facilitate surveillance for existing malnutrition and nutrition risk, but specific tools for the pediatric ICU population are lacking. Estimation of macronutrient requirements is often inaccurate; novel strategies to accurately determine energy expenditure are being explored. Indirect calorimetry remains the reference method for measuring energy expenditure. Enteral nutrition is the preferred route for nutrition in patients with a functioning gut. Early enteral nutrition and delivery of adequate macronutrients, particularly protein, have been associated with improved clinical outcomes. Delivery of enteral nutrition is often interrupted because of fasting around procedures and perceived intolerance. Objective measures for detection and management of intolerance to nutrient intake are required. In low-risk patients who are able to tolerate enteral nutrition, supplemental parenteral nutrition may be delayed during the first week of critical illness.

SUMMARY

Systematic research and consensus-based practices are expected to promote optimal nutritional practices in critically ill children with the potential to improve clinical outcomes.

Resolution of inflammation and sepsis survival are improved by dietary Ω-3 fatty acids

Critical conditions such as sepsis following infection or traumatic injury disturb the complex state of homeostasis that may lead to uncontrolled inflammation resulting in organ failure, shock and death. They are associated with endogenous mediators that control the onset of acute inflammatory response, but the central problem remains the complete resolution of inflammation. Omega-3 enriched lipid emulsions (Ω-3⁺ LEs) were used in experimental studies and clinical trials to establish homeostasis, yet with little understanding about their role on the resolution of inflammation and tissue regeneration. Here, we demonstrate that Ω-3 lipid emulsions (LEs) orchestrate inflammation-resolution/regeneration mechanism during sterile peritonitis and murine polymicrobial sepsis. Ω-3⁺ LEs recessed neutrophil infiltration, reduced pro-inflammatory mediators, reduced the classical monocyte and enhanced the non-classical monocytes/macrophages recruitment and finally increased the efferocytosis in sepsis. The actions of Ω-3⁺ LE were 5-lipoxygenase (5-LOX) and 12/15-lipoxygenase (12/15-LOX) dependent. Ω-3⁺ LEs shortened the resolution interval by 56%, stimulated the endogenous biosynthesis of resolution mediators lipoxin A4, protectin DX and maresin 1 and contributed to tissue regeneration. Ω-3⁺ LEs protected against hypothermia and weight loss and enhanced survival in murine polymicrobial sepsis. We highlighted a role of Ω-3⁺ LEs in regulating key mechanisms within the resolution terrain during murine sepsis. This might form the basis for a rational design of sepsis specific clinical nutrition.

Intravenous Carnitine Administration in Addition to Parenteral Nutrition With Lipid Emulsion May Decrease the Inflammatory Reaction in Postoperative Surgical Patients

BACKGROUND

A prospective randomized study was performed to investigate the validity of intravenous carnitine administration during postoperative parenteral nutrition (PN) with lipid emulsion.

METHODS

Patients undergoing surgery for gastric or colorectal cancer were enrolled in the study and were randomly divided into two groups (n = 8 in each group): 1) group L, who received a peripheral PN (PPN) solution of 7.5% glucose, 30% amino acid, and 20% lipid emulsion; and 2) group LC, who received the same PPN solution, as well as carnitine intravenously. PPN was performed from postoperative day (POD) 1 to POD4. Clinical and laboratory parameters were compared between the two groups; statistical significance was set at P < 0.05.

RESULTS

Serum carnitine concentrations were significantly higher in group LC on POD3 (P < 0.01) and POD7 (P = 0.01). Postoperative changes in laboratory parameters and morbidity were comparable between the two groups. However, the decrease in C-reactive protein from POD3 to POD7 was significantly greater in group LC than in group L (P = 0.011).

CONCLUSION

The results show that intravenous carnitine administration in addition to PN is safe and may be beneficial for recovery from postoperative inflammatory reactions.

Safflower (Carthamus tinctorius L.) oil during pregnancy and lactation influences brain excitability and cortex oxidative status in the rat offspring

OBJECTIVES

To evaluate how safflower oil (SFO) influences brain electrophysiology and cortical oxidative status in the offspring, mothers received a diet with SFO during brain development period.

METHODS

Beginning on the 14th day of gestation and throughout lactation, rats received safflower (safflower group - SG) or soybean oil (control group - CG) in their diet. At 65 days old, cortical spreading depression (CSD) and cortex oxidative status were analyzed in the offspring.

RESULTS

SG presented reduction of the CSD velocity as compared to the CG (SG: 3.24 ± 0.09; CG: 3.37 ± 0.07 mm/min). SFO reduced levels of lipid peroxidation by 39.4%. SG showed the following increases: glutathione-S-transferase, 40.8% and reduced glutathione, 34.3%. However, SFO decreased superoxide dismutase by 40.4% and catalase by 64.1%. To control for interhemispheric effects, since CSD was recorded only in the right cortex, we evaluated the oxidative status in both sides of the cortex; no differences were observed.

DISCUSSION

Data show that when SFO is consumed by the female rats during pregnancy and lactation, the offspring present long-term effects on brain electrophysiology and cortical oxidative state. The present study highlights the relevance of understanding the SFO intake of pregnant and lactating mammals.

Management of parenteral nutrition in critically ill patients

Artificial nutrition (AN) is necessary to meet the nutritional requirements of critically ill patients at nutrition risk because undernutrition determines a poorer prognosis in these patients. There is debate over which route of delivery of AN provides better outcomes and lesser complications. This review describes the management of parenteral nutrition (PN) in critically ill patients. The first aim is to discuss what should be done in order that the PN is safe. The second aim is to dispel “myths” about PN-related complications and show how prevention and monitoring are able to reach the goal of “near zero” PN complications. Finally, in this review is discussed the controversial issue of the route for delivering AN in critically ill patients. The fighting against PN complications should consider: (1) an appropriate blood glucose control; (2) the use of olive oil- and fish oil-based lipid emulsions alternative to soybean oil-based ones; (3) the adoption of insertion and care bundles for central venous access devices; and (4) the implementation of a policy of targeting “near zero” catheter-related bloodstream infections. Adopting all these strategies, the goal of “near zero” PN complications is achievable. If accurately managed, PN can be safely provided for most critically ill patients without expecting a relevant incidence of PN-related complications. Moreover, the use of protocols for the management of nutritional support and the presence of nutrition support teams may decrease PN-related complications. In conclusion, the key messages about the management of PN in critically ill patients are two. First, the dangers of PN-related complications have been exaggerated because complications are uncommon; moreover, infectious complications, as mechanical complications, are more properly catheter-related and not PN-related complications. Second, when enteral nutrition is not feasible or tolerated, PN is as effective and safe as enteral nutrition.

Effects of omega-3 fatty acid nutrition on mortality in septic patients: a meta-analysis of randomized controlled trials

Background

A previous systematic review and meta-analysis reported that omega-3 fatty acids nutrition may reduce mortality in septic patients. As new randomized controlled trials began to accumulate, we conducted an update.

Methods

A PubMed database was searched through Feb 2016, and randomized controlled trials comparing omega-3 fatty acids with control were selected by two reviewers independently.

Results

Eleven trials randomly assigning 808 patients were included in the present study. Using a fixed effects model, we found no significant effect of omega-3 fatty acids on overall mortality (risk ratio 0.84; 95 % confidence interval (CI): 0.67 to 1.05, P = 0.12), or infectious complications (risk ratio 0.95; 95 % CI: 0.72 to 1.25, P = 0.70). However, the duration of mechanical ventilation was markedly reduced by omega-3 fatty acids (weighted mean differences (WMD) = −3.82; 95 % CI: −4.61 to −3.04; P < 0.00001). A significant heterogeneity was found when the duration of hospital (I² = 93 %; WMD = −2.82; 95 % CI: −9.88 to 4.23, P = 0.43), or intensive care stay (I² = 87 %; WMD = −2.70; 95 % CI: −6.40 to 1.00, P = 0.15) were investigated.

Conclusions

Omega-3 fatty acids confer no mortality benefit but are associated with a reduction in mechanical ventilation duration in septic patients. However, low sample size and heterogeneity of the cohorts included in this analysis limits the generalizability of our findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0200-7) contains supplementary material, which is available to authorized users.

Parenteral Nutrition and Infection Risk in the Intensive Care Unit: A Practical Guide for the Bedside Clinician

The safety of parenteral nutrition (PN) administration in critically ill patients has been the subject of much controversy. Historically, PN administration has been associated with an increased risk of bacterial and fungal infections, leading to significant morbidity and mortality. Much of the data showing increased infectious complications compared with either no nutrition or enteral nutrition was derived from early studies conducted in the 1980s-2000s. Poor glucose control and hyperalimentation are confounding factors in many early studies, making it difficult to determine the true PN infection risks. While PN studies conducted during the past 10 years have failed to show the same infection rates, these risks continue to be cited as dogma. Potential reasons for such discordant results include improved glycemic control, avoidance of overfeeding, and improved sterility and central venous catheter care. Understanding the true infectious risk of PN administration in the intensive care unit is necessary to optimize patient care, as inappropriately withholding such nutrition is potentially deleterious. This review is meant to serve as a practical guide to the bedside clinician who is evaluating the risks and benefits of initiating PN in a critically ill patient. Each component of PN will be evaluated based on risk of infection, and the potential ways to mitigate risks will be discussed.

Fish Oil-Based Fat Emulsion Reduces Acute Kidney Injury and Inflammatory Response in Antibiotic-Treated Polymicrobial Septic Mice

Acute kidney injury (AKI) is a common complication in sepsis. This study compared the effects of a fish oil-based with a mixed oil fat emulsion on remote renal injury in an antibiotic-treated septic murine model. Mice were randomly assigned to a normal control (NC) group and three septic groups. Sepsis was induced by cecal ligation and puncture (CLP). The antibiotic was injected intraperitoneally (IP) after CLP and then daily till the time of sacrifice. Three hours after antibiotic treatment, one of the septic groups was injected IP with a fish oil-based emulsion (FO), while the other two groups were given either a mixed oil emulsion (MO) or saline (SC). The septic groups were further divided into two separate time groups, with blood and kidneys samples collected at 24 h or 72 h post-CLP. The results showed that sepsis leads to the activation of neutrophils, T helper (Th)1/Th-2/Th-17 and Treg cells (p < 0.05). Plasma NGAL and mRNA expressions of renal MyD88 and TLR4 were also enhanced (p < 0.05). Compared to the SC group, the group given the fish oil-based emulsion had decreased plasma NGAL by 22% and Treg by 33%. Furthermore, renal gene expressions of MyD88 and TLR4 reduced by 46% and 62%, respectively, whereas heat shock protein 70 and peroxisome proliferator-activated receptor-γ increased by 158% and 69%, respectively (p < 0.05), at Day 3 after CLP. These results suggest that administration of a fish oil-based emulsion has favorable effects, maintaining blood T cell percentage, downregulating Treg expression, attenuating systemic and local inflammation and offering renal protection under conditions of antibiotic-treated polymicrobial sepsis.

Comparison of Formulas Based on Lipid Emulsions of Olive Oil, Soybean Oil, or Several Oils for Parenteral Nutrition: A Systematic Review and Meta-Analysis

Many studies have reported that olive oil-based lipid emulsion (LE) formulas of soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOF) may be a viable alternative for parenteral nutrition. However, some randomized controlled clinical trials (RCTs) have raised concerns regarding the nutritional benefits and safety of SMOFs. We searched principally the MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Scopus, EMBASE, and Cochrane Central Register of Controlled Trials databases from inception to March 2014 for the relevant literature and conducted a meta-analysis of 15 selected RCTs that 1) compared either olive oil- or SMOF-based LEs with soybean oil-based LEs and 2) reported plasma concentrations of α-tocopherol, oleic acid, and ω-6 (n-6) and ω-3 (n-3) long-chain polyunsaturated fatty acids (PUFAs) and liver concentrations of total bilirubin and the enzymes alanine transaminase, aspartate transaminase, alkaline phosphatase, and γ-glutamyl transferase. The meta-analysis suggested that SMOF-based LEs were associated with higher plasma concentrations of plasma α-tocopherol, oleic acid, and the ω-3 PUFAs eicosapentaenoic and docosahexaenoic acid. Olive oil- and SMOF-based LEs correlated with lower plasma concentrations of long-chain ω-6 PUFAs and were similar to soybean oil-based LEs with regard to their effects on liver function indicators. In summary, olive oil- and SMOF-based LEs have nutritional advantages over soybean oil-based LEs and are similarly safe. However, their performance in clinical settings requires further investigation.

Does the type of parenteral lipids matter? A clinical hint in critical illness

BACKGROUND & AIMS

An altered lipid profile is common among intensive care unit (ICU) patients, but evidence regarding the impact of different fatty acid (FA) emulsions administered to patients requiring parenteral nutrition (PN) is scarce. This study aimed to compare the plasma triglycerides (TG) response to two types of commercial lipid emulsions: a structured mixture of long- and medium-chain triglycerides (LCT/MCT) or LCTs with n-9 FA (LCT+) in ICU patients.

METHODS

In this retrospective observational study conducted in a multidisciplinary ICU: two groups were defined by the type of emulsion used. Inclusion criteria were: consecutive patients on PN staying ≥4 days with one TG determination before commencing PN and at least one during PN. Recorded variables included energy intake, amount and type of nutritional lipids, propofol dose, glucose and protein intake, laboratory parameters, and all drugs received. Hypertriglyceridemia (hyperTG) was defined as TG >2 mmol/L.

RESULTS

The dynamic impact of the emulsion was analyzed in 187/757 patients completing the inclusion criteria (112 LCT/MCT and 75 LCT+). The demographic variables, severity indices, diagnostic categories, and outcomes did not differ between the two groups. Seventy-seven patients (41%) presented hyperTG. Both groups received similar daily energy (1604 versus 1511 kcal/day), lipids (60 versus 61 g/day), and glucose intake (233 versus 197 g/day). There was no increase of TG concentration in those receiving the LCT/MCT emulsion compared to those receiving the LCT+ emulsion (0 and 0.2 mmol/L, respectively, p < 0.05).

CONCLUSION

LCT/MCT emulsions are associated with a less pronounced increase of plasma TG levels than LCT+ emulsions.

Nutrition and metabolic support for critically ill patients

PURPOSE OF REVIEW

Acute critical illness increases the risk of malnutrition, are more obese, and have multiple comorbidities and frequent pre-existing nutritional deficits. There is a vast amount of research and literature being written on nutritional practices in the critically ill. We review and discuss herein the important nutrition literature over the past 12 months.

RECENT FINDINGS

Sarcopenia, defined as loss of skeletal mass and strength, is associated with increased mortality and morbidity, particularly in elderly patients with trauma. Ultrasound is emerging as a noninvasive and promising method of measuring muscularity. Measuring gastric residuals and postpyloric feeding may not decrease rates of pneumonia in critically ill patients. Trophic and full feeding lead to similar long-term functional and cognitive outcomes in patients with acute respiratory distress syndrome.

SUMMARY

Nutrition and metabolic support of critically ill patients is a complex and diverse topic. Nutritional measurements, requirements, and modes and routes of delivery are currently being studied to determine the best way to treat these complicated patients. We present just a few of the current controversial topics in this fascinating arena.

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.

[Fish oil containing lipid emulsions in critically ill patients: Critical analysis and future perspectives]

Third-generation lipid emulsions (LE) are soybean oil sparing strategies with immunomodulatory and antiinflammatory effects. Current evidence supporting the use of intravenous (i.v) fish oil (FO) LE in critically ill patients requiring parenteral nutrition or receiving enteral nutrition (pharmaconutrient strategy) mainly derives from small phase ii clinical trials in heterogenous intensive care unit patient's population. Over the last three years, there have been published different systematic reviews and meta-analyses evaluating the effects of FO containing LE in the critically ill. Recently, it has been demonstrated that i.v FO based LE may be able to significantly reduce the incidence of infections as well as mechanical ventilation days and hospital length of stay. Nonetheless, more robust evidence is required before giving a definitive recommendation. Finally, we strongly believe that a dosing study is required before new phase iii clinical trials comparing i.v FO containing emulsions versus other soybean oil strategies can be conducted.

Nutritional support in critical illness and recovery

An adequate nutritional status is crucial for optimum function of cells and organs, and for wound healing. Options for artificial nutrition have greatly expanded in the past few decades, but have concomitantly shown limitations and potential side-effects. Few rigorous randomised controlled trials (RCTs) have investigated enteral or parenteral nutritional support, and evidence-based clinical guidance is largely restricted to the first week of critical illness. In the early stages of critical illness, whether artificial feeding is better than no feeding intervention has been given little attention in existing RCTs. Expected beneficial effects of various forms of early feeding interventions on rates of morbidity or mortality have generally not been supported by results of recent high-quality RCTs. Thus, whether nutritional interventions early in an intensive care unit (ICU) stay improve outcomes remains unclear. Trials assessing feeding interventions that continue after the first week of critical illness and into the post-ICU and post-hospital settings are clearly needed. Although acute morbidity and mortality will remain important safety parameters in such trials, primary outcomes should perhaps, in view of the adjunctive nature of nutritional intervention in critical illness, be focused on physical function and assessed months or even years after patients are discharged from the ICU. This Series paper is based on results of high-quality RCTs and provides new perspectives on nutritional support during critical illness and recovery.

Long-chain polyunsaturated fatty acids supplementation in preterm infants

PURPOSE OF REVIEW

Extremely low birth weight and very low birth weight infants are born immature and are commonly sick and are, therefore, not able to receive appropriate enteral or sufficient parenteral nutrition to meet the needs for optimal brain, lung and gut growth and development.

RECENT FINDINGS

We provide an updated view of essential fatty acid metabolism and discuss the potential protective effect of fatty acids that serve as precursors for eicosanoids and docosanoids. The balance of n-3 or n-6 long-chain polyunsaturated fatty acids (LCPUFAs) supplied may enhance or ameliorate the effects of hypoxia, inflammation, infection, thrombosis and oxidative damage of key organs (lung, brain and retina). In addition, n-3 and n-6 LCPUFAs are necessary for normal structure and function of the central nervous system and sensory organ development. These lipids generate eicosanoids that are mediators of oxidative damage, as well as potential protectors of retina, brain cortex, lung and vascular endothelium.

SUMMARY

n-3 and n-6 LCPUFAs may condition in part the long-term consequences of preterm birth. Early n-3 and n-6 LCPUFA supply may moderate the impact of hypoxia and oxidative damage, thus affecting the recovery from injury, later organ (brain, retina, lung, gut, liver and skin) growth and neurodevelopmental outcomes.

Proceedings From FDA/A.S.P.E.N. Public Workshop: Clinical Trial Design for Intravenous Fat Emulsion Products, October 29, 2013

The development of intravenous fat emulsion (IVFE) is the culmination of physiological, biochemical, nutritional, and medical scientific advancements. IVFEs have the ability to deliver critical nutritional substrates to the patient. Recent literature purports that they may also play roles in modulation of immune functionality and pulmonary physiology, but data supporting these potential benefits are limited. While soybean-based IVFEs have comprised the dominant fat in U.S. markets, a number of other novel IVFEs may prove to optimize the care of children and adults in both hospitalized and home settings. The October 2013 U.S. Food and Drug Administration (FDA)/American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) Public Workshop brought together scientists, researchers, and clinical experts to present updated clinical perspectives of IVFEs, including historical development, current state of usage throughout the world, and considerations for the regulatory approval of new IVFEs in the United States.

The effects of different IV fat emulsions on clinical outcomes in critically ill patients

OBJECTIVE

To examine the effects of different IV fat emulsions on clinical outcomes in critically ill patients.

DESIGN

Secondary analysis of data from a prospective multicenter study.

SETTING

An international sample of ICUs.

PATIENTS

Adult patients who were admitted to the ICU for more than 72 hours, were mechanically ventilated within 48 hours, received exclusive parenteral nutrition for more than or equal to 5 days, and did not change IV fat emulsion type during the data collection period.

INTERVENTIONS

Demographic and clinical data were collected for up to 12 days, until death, or discharge from the ICU, whichever came first. Clinical outcomes were recorded at 60 days following ICU admission.

MEASUREMENTS

Lipid-free, soybean, medium-chain triglyceride, olive, and fish oils in parenteral nutrition were compared using an adjusted Cox proportional hazard model to examine time to termination of mechanical ventilation alive, time to ICU discharge alive, and time to hospital discharge alive.

MAIN RESULTS

A total of 451 patients were included in this study: 70 (15.5%) in the lipid-free group, 223 (49.5%) in the soybean oil group, 65 (14.4%) in the medium-chain triglyceride group, 74 (16.4%) in the olive oil group, and 19 (4.9%) in the fish oil group. When compared with lipid-free parenteral nutrition, patients who received fish oil had a faster time to ICU discharge alive (hazard ratio, 1.84; 95% CI, 1.01-3.34; p = 0.05). When compared with soybean oil, patients who received olive oil or fish oil had a shorter time to termination of mechanical ventilation alive (hazard ratio, 1.43; 95% CI, 1.06-1.93; p = 0.02 and hazard ratio, 1.67; 95% CI, 1.00-2.81; p = 0.05, respectively) and a shorter time to ICU discharge alive (hazard ratio, 1.76; 95% CI, 1.30-2.39; p < 0.001 and hazard ratio, 2.40; 95% CI, 1.43-4.03; p = 0.001, respectively).

CONCLUSIONS

Use of alternative IV fat emulsions in parenteral nutrition, particularly olive and fish oil, was associated with improved clinical outcomes.