The Impact of Intravenous Fat Emulsion Administration in Acute Lung Injury

Effects of fish oil-containing nutrition supplementation in adult sepsis patients: a systematic review and meta-analysis

BACKGROUND

Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. Although fish oil has been used as an immunonutritional preparations for the treatment of sepsis patients, there is still controversy as to whether it is beneficial to them. We systematically reviewed published clinical trial data to evaluate the effectiveness of fish oil-containing nutrition supplementation in sepsis patients.

METHODS

A systematic search was undertaken in PubMed, Embase, Chinese Biomedicine Database, the Cochrane Library and the China Knowledge Resource Integrated Database to obtain clinical controlled trails. RCTs on nutrition therapy containing fish oil among adult sepsis patients were selected for analysis in comparison with routine therapy.

RESULTS

Twenty-five published trials were included in the meta-analysis. Fish oil-containing nutrition supplementation reduced the mortality compared with the control group (relative risk (RR) 0.74, I ² = 0%). Fish oil also shortened the ICU stay (MD -3.57 days; 95% CI -4.54, -2.59; p<0.00001; I ² = 76%), hospital stay (MD -9.92 days; 95% CI -15.37, -4.46; p = 0.0004; I ² = 91%) and the duration of mechanical ventilation support (MD -2.26; 95% CI -4.27, -0.26; p = 0.03; I ² = 83%). A subgroup analysis based on the route of administration revealed that parenteral administration of fish oil could reduce mortality in septic patients (RR =0.68, I ² = 0%), but no significant difference in mortality was observed in the fish oil group administered by enteral route (RR = 0.80, I ² = 0%). No statistically significant publication biases were detected for the above clinical endpoints (p>0.05).

CONCLUSIONS

Parenteral nutrition containing fish oil could significantly decrease mortality in sepsis patients while enteral administration could not. Fish oil-containing nutrition supplementation.

Use of Intravenous Soybean and Fish Oil Emulsions in Pediatric Intestinal Failure-Associated Liver Disease: A Multicenter Integrated Analysis Report on Extrahepatic Adverse Events

OBJECTIVE

To compare extrahepatic adverse events during fish oil lipid emulsion (FOLE) or soybean oil lipid emulsion (SOLE) treatment in children with intestinal failure-associated liver disease (IFALD).

STUDY DESIGN

In this multicenter integrated analysis, bleeding, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), infections, and signs of lipid emulsion intolerance were compared between FOLE recipients (1 g/kg/d) (n = 189) and historical controls who received SOLE (≤3 g/kg/d) (n = 73).

RESULTS

When compared with SOLE recipients, FOLE recipients had a lower gestational age (30.5 vs 33.0 weeks; P = .0350) and higher baseline direct bilirubin (DB) (5.8 vs 3.0 mg/dL; P < .0001). FOLE recipients had a decreased incidence of bleeding (P < .0001), BPD (P < .001), ROP (P < .0156), bacterial and fungal infections (P < .0001), and lipid intolerance signs (P < .02 for all). Patients with bleeding vs patients without bleeding had higher baseline DB; the ORs for baseline DB (by mg/dL) and treatment (FOLE vs SOLE) were 1.20 (95% CI: 1.10, 1.31; P ≤ .0001) and 0.22 (95% CI: 0.11, 0.46; P ≤ .0001), respectively. In preterm infants, a higher BPD (P < .0001) and ROP incidence (P = .0071) was observed in SOLE recipients vs FOLE recipients.

CONCLUSIONS

Children with IFALD who received FOLE had fewer extrahepatic adverse events, including a decreased incidence of bleeding, preterm comorbidities, and lipid intolerance signs compared with children with IFALD who received SOLE. TRIAL REGISTRATION CLINICALTRIALS.GOV: NCT00910104 and NCT00738101.

Phospholipases A2 as biomarkers in ARDS

Acute respiratory distress syndrome (ARDS) is a multifactorial life-threatening lung injury, characterized by diffuse lung inflammation and increased alveolocapillary barrier permeability. The different stages of ARDS have distinctive biochemical and clinical profiles. Despite the progress of our understanding on ARDS pathobiology, the mechanisms underlying its pathogenesis are still obscure. Herein, we review the existing literature about the implications of phospholipases 2 (PLA2s), a large family of enzymes that catalyze the hydrolysis of fatty acids at the sn-2 position of glycerophospholipids, in ARDS-related pathology. We emphasize on the versatile way of participation of different PLA2s isoforms in the distinct ARDS subgroup phenotypes by either potentiating lung inflammation and damage or by preserving the normal lung. Current research supports that PLA2s are associated with the progression and the outcome of ARDS. We herein discuss the transcellular communication of PLA2s through secreted extracellular vesicles and suggest it as a new mechanism of PLA2s involvement in ARDS. Thus, the elucidation of the spatiotemporal features of PLA2s expression may give new insights and provide valuable information about the risk of an individual to develop ARDS or advance to more severe stages, and potentially identify PLA2 isoforms as biomarkers and target for pharmacological intervention.

Intravenous Lipid Emulsions Affect Respiratory Outcome in Preterm Newborn: A Case-Control Study

(1) Background: Hypertriglyceridemia (HiTG) is a metabolic complication of intravenous lipid emulsions (ILEs) infusion. We aimed to evaluate the influence of HiTG on the respiratory outcome of preterm babies; (2) Methods: We enrolled, in a case-control study, newborns with gestational age <32 weeks or birth weight <1500 g, over a 3-year period. They were divided into cases and controls; cases were defined by the detection of HiTG defined as serum triglycerides (TG) value >150 mg/dL; (3) Results: We enrolled 40 cases and 105 controls. Cases had an increased incidence of bronchopulmonary dysplasia (30.0% vs. 14.3%, p < 0.05) and longer duration of invasive mechanical ventilation (7 days, 95% CI 4-10 days vs. 4 days, 95% CI 1-7 days, p < 0.01) compared to controls. Multivariate analysis confirmed that HiTG independently influenced the duration of invasive mechanical ventilation, also in the subgroups with gestational age ≤28 + 6/7 weeks or birth weight ≤1000 g; (4) Conclusion: Newborns with HiTG related to ILEs had a longer duration of invasive mechanical ventilation. Temporary suspension or reduction in ILEs in the case of HiTG is associated with an improvement of respiratory outcome.

Novel Strategies to Prevent Total Parenteral Nutrition-Induced Gut and Liver Inflammation, and Adverse Metabolic Outcomes

Total parenteral nutrition (TPN) is a life-saving therapy administered to millions of patients. However, it is associated with significant adverse effects, namely liver injury, risk of infections, and metabolic derangements. In this review, the underlying causes of TPN-associated adverse effects, specifically gut atrophy, dysbiosis of the intestinal microbiome, leakage of the epithelial barrier with bacterial invasion, and inflammation are first described. The role of the bile acid receptors farnesoid X receptor and Takeda G protein-coupled receptor, of pleiotropic hormones, and growth factors is highlighted, and the mechanisms of insulin resistance, namely the lack of insulinotropic and insulinomimetic signaling of gut-originating incretins as well as the potentially toxicity of phytosterols and pro-inflammatory fatty acids mainly released from soybean oil-based lipid emulsions, are discussed. Finally, novel approaches in the design of next generation lipid delivery systems are proposed. Propositions include modifying the physicochemical properties of lipid emulsions, the use of lipid emulsions generated from sustainable oils with favorable ratios of anti-inflammatory n-3 to pro-inflammatory n-6 fatty acids, beneficial adjuncts to TPN, and concomitant pharmacotherapies to mitigate TPN-associated adverse effects.

Clinical Nutrition in Critical Care Medicine - Guideline of the German Society for Nutritional Medicine (DGEM)

PURPOSE

Enteral and parenteral nutrition of adult critically ill patients varies in terms of the route of nutrient delivery, the amount and composition of macro- and micronutrients, and the choice of specific, immune-modulating substrates. Variations of clinical nutrition may affect clinical outcomes. The present guideline provides clinicians with updated consensus-based recommendations for clinical nutrition in adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function.

METHODS

The former guidelines of the German Society for Nutritional Medicine (DGEM) were updated according to the current instructions of the Association of the Scientific Medical Societies in Germany (AWMF) valid for a S2k-guideline. According to the S2k-guideline classification, no systematic review of the available evidence was required to make recommendations, which, therefore, do not state evidence- or recommendation grades. Nevertheless, we considered and commented the evidence from randomized-controlled trials, meta-analyses and observational studies with adequate sample size and high methodological quality (until May 2018) as well as from currently valid guidelines of other societies. The liability of each recommendation was described linguistically. Each recommendation was finally validated and consented through a Delphi process.

RESULTS

In the introduction the guideline describes a) the pathophysiological consequences of critical illness possibly affecting metabolism and nutrition of critically ill patients, b) potential definitions for different disease phases during the course of illness, and c) methodological shortcomings of clinical trials on nutrition. Then, we make 69 consented recommendations for essential, practice-relevant elements of clinical nutrition in critically ill patients. Among others, recommendations include the assessment of nutrition status, the indication for clinical nutrition, the timing and route of nutrient delivery, and the amount and composition of substrates (macro- and micronutrients); furthermore, we discuss distinctive aspects of nutrition therapy in obese critically ill patients and those treated with extracorporeal support devices.

CONCLUSION

The current guideline provides clinicians with up-to-date recommendations for enteral and parenteral nutrition of adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function. The period of validity of the guideline is approximately fixed at five years (2018-2023).

Acute Respiratory Distress Syndrome: Etiology, Pathogenesis, and Summary on Management

The acute respiratory distress syndrome (ARDS) has multiple causes and is characterized by acute lung inflammation and increased pulmonary vascular permeability, leading to hypoxemic respiratory failure and bilateral pulmonary radiographic opacities. The acute respiratory distress syndrome is associated with substantial morbidity and mortality, and effective treatment strategies are limited. This review presents the current state of the literature regarding the etiology, pathogenesis, and management strategies for ARDS.

Lipid emulsions for parenterally fed term and late preterm infants

BACKGROUND

Lipid emulsions (LE) form a vital component of infant nutrition for critically ill, late preterm or term infants, particularly for those with gastrointestinal failure. Conventionally used soybean oil-based LE (S-LE) have high polyunsaturated fatty acid (PUFA) content and phytosterols, which may contribute to adverse effects including parenteral nutrition-associated liver disease (PNALD).

OBJECTIVES

To compare the safety and efficacy of all LE for parenteral nutrition (PN) in term and late preterm infants (between 34 weeks' gestation and 36 weeks' and six days' gestation) with or without surgical conditions or PNALD within first six months of life, using all possible direct comparisons.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 5), MEDLINE (1946 to 18 June 2018), Embase (1974 to 18 June 2018), CINAHL (1982 to 18 June 2018), MIDRIS (1971 to 31 May 2018), conference proceedings, trial registries (ClinicalTrials.gov and the WHO's Trials Registry), and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled studies in term and late preterm infants, with or without surgical conditions or PNALD.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of Cochrane Neonatal. We used the GRADE approach to assess the quality of evidence for important outcomes in addition to reporting the conventional statistical significance of results.

MAIN RESULTS

The review included nine randomised studies (n = 273). LE were classified in three broad groups: 1. all fish oil-containing LE including pure fish oil (F-LE) and multisource LE (e.g. medium-chain triglycerides (MCT)-olive-fish-soybean oil-LE (MOFS-LE), MCT-fish-soy oil-LE (MFS-LE) and olive-fish-soy-LE (OFS-LE)); 2. conventional pure S-LE; 3. alternative-LE (e.g. MCT-soy-LE (MS-LE), olive-soy-LE (OS-LE) and borage oil-based LE).We considered four broad comparisons: 1. all fish oil LE versus non-fish oil LE (6 studies; n = 182); 2. fish oil LE versus another fish oil LE (0 studies); 3. alternative-LE versus S-LE (3 studies; n = 91); 4. alternative-LE versus another alternative-LE (0 studies) in term and late preterm infants (0 studies), term and late preterm infants with surgical conditions (7 studies; n = 233) and term and late preterm infants with PNALD/cholestasis (2 studies; n = 40).PNALD/cholestasis was defined as conjugated bilirubin (Cbil) 2 mg/dL or greater and resolution of PNALD/cholestasis as Cbil less than 2 mg/dL. We put no restriction on timing of PNALD detection. There was heterogeneity in definitions and time points for detecting PNALD in the included studies.We found one study each in surgical infants and in infants with cholestasis, showing no evidence of difference in incidence or resolution of PNALD/cholestasis (Cbil cut-off: 2 mg/dL) with use of fish oil-containing LE compared to S-LE.We considered an outcome allowing for any definition of PNALD (different Cbil cut-off levels). In infants with surgical conditions and no pre-existing PNALD, meta-analysis showed no difference in the incidence of PNALD/cholestasis (any definition) with use of fish oil-containing LE compared to S-LE (typical risk ratio (RR) 1.20, 95% confidence interval (CI) 0.38 to 3.76; typical risk difference (RD) 0.03, 95% CI -0.14 to 0.20; 2 studies; n = 68; low-quality evidence). In infants with PNALD/cholestasis (any definition), use of fish oil-LEs was associated with significantly less cholestasis compared to the S-LE group (typical risk ratio (RR) 0.54, 95% confidence interval (CI) 0.32 to 0.91; typical risk difference (RD) -0.39, 95% CI -0.65 to -0.12; number needed to treat for additional beneficial outcome (NNTB) 3, 95% CI 2 to 9; 2 studies; n = 40; very low-quality evidence). This outcome had very low number of participants from two small studies with differences in study methodology and early termination in one study, which increased uncertainty about the effect estimates.One study in infants with cholestasis reported significantly better weight gain with a pure fish oil LE compared to a 10% S-LE (45 g/week, 95% CI 15.0 to 75.0; n = 16; very low-quality evidence). There were no significant differences in growth parameters in studies with surgical populations.For the secondary outcomes, in infants with cholestasis, one study (n = 24) reported significantly lower conjugated bilirubin levels but higher gamma glutamyl transferase levels with MOFS-LE (SMOFlipid) versus S-LE (Intralipid) and another study (n = 16), which was terminated early, reported significantly higher rates of rise in alanine aminotransferase (ALT) and conjugated bilirubin levels in the S-LE group compared to pure F-LE (Omegaven).In surgical infants, two studies each reported on hypertriglyceridaemia and Cbil levels with one study in each outcome showing significant benefit with use of a F-LE and the other study showing no difference between the groups. Meta-analysis was not performed for either of these outcomes as there were only two studies showing conflicting results with high heterogeneity between the studies.There was no evidence of differences in death, sepsis, alkaline phosphatase and ALT levels in infants with surgical conditions or cholestasis (very low-quality evidence).One study reported neurodevelopmental outcomes at six and 24 months in infants with surgical conditions (n = 11) with no evidence of difference with use of pure F-LE versus S-LE. Another study in infants with cholestasis (n = 16) reported no difference in head growth velocity between pure F-LE versus S-LE.GRADE quality of evidence ranged from low to very low as the included studies were small single-centre studies. Three of the six studies that contributed data to the review were terminated early for various reasons.

AUTHORS' CONCLUSIONS

Based on the current review, there is insufficient data from randomised studies to determine with any certainty, the potential benefit of any LE including fish oil-containing LEs over another LE, for prevention or resolution of PNALD/cholestasis or any other outcomes in term and late preterm infants with underlying surgical conditions or cholestasis. There were no studies in infants without surgical conditions or cholestasis.Further research is required to establish role of fish oil or lipids from other sources in LEs to improve PNALD/cholestasis, and other clinical outcomes in parenterally fed term and late preterm infants.

Lipid emulsions for parenterally fed preterm infants

BACKGROUND

Conventionally used soybean oil-based lipid emulsion (S-LE) have high polyunsaturated fatty acid (PUFA) content and phytosterols that may contribute to adverse effects in preterm infants. The newer lipid emulsions (LE) from different lipid sources are currently available for use in preterm infants.

OBJECTIVES

To compare the safety and efficacy of all LE for parenteral nutrition (PN) in preterm infants (less than 37 weeks' gestation) including preterm infants with surgical conditions or parenteral nutrition-associated liver disease (PNALD)/cholestasis using direct comparisons and pair-wise meta-analyses.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 5), MEDLINE (1946 to 18 June 2018), Embase (1974 to 18 July 2018), CINAHL (1982 to 18 June 2018), MIDRIS (1971 to 31 May 2018), conference proceedings, trial registries (ClinicalTrials.gov and WHO's Trials Registry and Platform), and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled studies in preterm infants with or without surgical conditions or PNALD within the first six months of life.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of Cochrane Neonatal. We used the GRADE approach to assess the quality of evidence for important outcomes in addition to reporting statistical significance of results.

MAIN RESULTS

We included 29 studies (n = 2037) in this review. LE were classified in three broad groups: 1. all fish oil-containing LE including pure fish oil-LE (F-LE) and multisource LE (e.g. medium-chain triglycerides (MCT)-olive-fish-soybean oil-LE (MOFS-LE), MCT-fish-soybean oil-LE (MFS-LE) and olive-fish-soybean oil-LE (OFS-LE); 2. conventional S-LE; 3. alternative-LE (e.g. MCT-soybean oil-LE (MS-LE), olive-soybean oil-LE and borage oil-based LE).We considered the following broad comparisons: fish oil LE versus non-fish oil LE; fish oil LE versus another fish oil LE; alternative-LE versus S-LE; alternative-LE versus another alternative-LE in preterm infants less than 37 weeks' gestation, preterm infants with surgical conditions and preterm infants with PNALD/cholestasis. Separate subgroup comparisons of each LE preparation were included within these broader groups.Most studies in preterm infants used PN for mean duration of four weeks or less and for longer duration in infants with cholestasis or surgical conditions.We defined the primary outcome of PNALD/cholestasis as conjugated bilirubin (Cbil) 2 mg/dL or greater and resolution of PNALD/cholestasis as Cbil less than 2 mg/dL. There was heterogeneity in definitions used by the included studies with Cbil cut-offs ranging from 17.1 μmol/L (1 mg/dL) up to 50 μmol/L (about 3 mg/dL).In preterm infants, meta-analysis found no evidence of a difference in the incidence of PNALD/cholestasis (Cbil cut-off: 2 mg/dl) between fish oil-LEs and all non-fish oil LEs (typical risk ratio (RR) 0.61, 95% confidence interval (CI) 0.24 to 1.56; typical risk difference (RD) -0.03, 95% CI -0.08 to 0.02; 4 studies; n = 328; low-quality evidence).We also considered an outcome allowing for any definition of PNALD (different Cbil cutoffs). In the meta-analysis for PNALD/cholestasis, using any definition and restricted to low or unclear risk of bias studies, there was no evidence of a difference between fish oil LE and all non-fish oil LE for incidence of cholestasis (typical RR 0.80, 95% CI 0.53 to 1.21; typical RD -0.02, 95% CI -0.05 to 0.02; 10 studies; n = 1024; low-quality evidence). There was no evidence of difference in subgroup meta-analyses of individual LE types in any comparison.In preterm infants with surgical conditions or cholestasis, there was only one small study each reporting no evidence of a difference in incidence or resolution of cholestasis respectively with use of a pure F-LE versus S-LE (using a Cbil cut-off of 2 mg/dL).In preterm infants with PNALD/cholestasis (using any definition), the meta-analysis showed significantly less cholestasis with the use of fish oil-LE compared to S-LE (typical RR 0.54, 95% CI 0.32 to 0.91; typical RD -0.39, 95% CI -0.65 to -0.12; number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 2 to 9; 2 studies; n = 40; very low-quality evidence). However, this outcome had a very low number of participants from two small studies with methodological differences, one of which was terminated early, increasing the uncertainty about effect estimates.There were no differences between LE types in pair-wise meta-analyses for growth in preterm infants. There was paucity of studies in preterm infants with surgical conditions or cholestasis to perform meta-analyses for growth and most other outcomes.In the secondary outcomes for preterm infants, there was no difference between fish-oil LE and non-fish oil LE in meta-analysis for severe retinopathy of prematurity (ROP) (stage 3 or greater, or requiring surgery: typical RR 0.80, 95% CI 0.55 to 1.16; typical RD -0.03, 95% CI -0.07 to 0.02; 7 studies; n = 731; very low-quality evidence). There were no differences in the LE types in pair-wise meta-analyses for death, bronchopulmonary dysplasia (BPD), ventilation duration, patent ductus arteriosus, sepsis, necrotising enterocolitis, intraventricular haemorrhage, periventricular leukomalacia, jaundice, hyperglycaemia, hypertriglyceridaemia, intrahepatocellular lipid content and conjugated bilirubin levels in any comparison.In surgical infants, one study (n = 19) reported no differences in death, sepsis rates, Cbil and neurodevelopmental outcomes with pure F-LE versus S-LE.In infants with cholestasis, there were no evidence of differences in death or sepsis in meta-analyses between fish oil-LE and S-LE; (2 studies; n = 40; very low-quality evidence).

AUTHORS' CONCLUSIONS

In the current review, we did not find any particular LE with or without fish oil to be better than another LE in preterm infants for prevention of PNALD/cholestasis, growth, mortality, ROP, BPD and other neonatal outcomes.In preterm infants with surgical conditions or cholestasis, there is currently insufficient evidence from randomised studies to determine with any certainty if fish oil LEs offer advantage in prevention or resolution of cholestasis or in any other clinical outcome.Further research, with larger well-designed trials, is warranted to evaluate the ideal composition of LE in preterm infants and the role of fish oil-containing and other LEs in the prevention and resolution of PNALD, ROP and other clinical outcomes.

Lipid emulsions for parenterally fed preterm infants

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

The primary objective is to compare the effectiveness and safety of lipid formulations from different sources, including soybean oil‐based, multicomponent, olive oil‐based, and fish oil–based, in parenterally fed preterm infants.

The secondary objective is to determine the effectiveness and safety of alternative lipid emulsions compared with soybean oil‐based lipid emulsions in relation to gestational age (less than 30 weeks' gestation; 30 weeks' gestation or more), birth weight (1000 grams or less; more than 1000 grams), clinical condition (surgical patients, patients with established cholestasis).

Lipids in the intensive care unit: Recommendations from the ESPEN Expert Group

This article summarizes the presentations given at an ESPEN Workshop on "Lipids in the ICU" held in Tel Aviv, Israel in November 2014 and subsequent discussions and updates. Lipids are an important component of enteral and parenteral nutrition support and provide essential fatty acids, a concentrated source of calories and building blocks for cell membranes. Whilst linoleic acid-rich vegetable oil-based enteral and parenteral nutrition is still widely used, newer lipid components such as medium-chain triglycerides and olive oil are safe and well tolerated. Fish oil (FO)-enriched enteral and parenteral nutrition appears to be well tolerated and confers additional clinical benefits, particularly in surgical patients, due to its anti-inflammatory and immune-modulating effects. Whilst the evidence base is not conclusive, there appears to be a potential for FO-enriched nutrition, particularly administered peri-operatively, to reduce the rate of complications and intensive care unit (ICU) and hospital stay in surgical ICU patients. The evidence for FO-enriched nutrition in non-surgical ICU patients is less clear regarding its clinical benefits and additional, well-designed large-scale clinical trials need to be conducted in this area. The ESPEN Expert Group supports the use of olive oil and FO in nutrition support in surgical and non-surgical ICU patients but considers that further research is required to provide a more robust evidence base.

Obesity-Induced Endoplasmic Reticulum Stress Causes Lung Endothelial Dysfunction and Promotes Acute Lung Injury

RETRACTED: Obesity is a significant risk factor for acute respiratory distress syndrome. The mechanisms underlying this association are unknown. We recently showed that diet-induced obese mice exhibit pulmonary vascular endothelial dysfunction, which is associated with enhanced susceptibility to LPS-induced acute lung injury. Here, we demonstrate that lung endothelial dysfunction in diet-induced obese mice coincides with increased endoplasmic reticulum (ER) stress. Specifically, we observed enhanced expression of the major sensors of misfolded proteins, including protein kinase R-like ER kinase, inositol-requiring enzyme α, and activating transcription factor 6, in whole lung and in primary lung endothelial cells isolated from diet-induced obese mice. Furthermore, we found that primary lung endothelial cells exposed to serum from obese mice, or to saturated fatty acids that mimic obese serum, resulted in enhanced expression of markers of ER stress and the induction of other biological responses that typify the lung endothelium of diet-induced obese mice, including an increase in expression of endothelial adhesion molecules and a decrease in expression of endothelial cell-cell junctional proteins. Similar changes were observed in lung endothelial cells and in whole-lung tissue after exposure to tunicamycin, a compound that causes ER stress by blocking N-linked glycosylation, indicating that ER stress causes endothelial dysfunction in the lung. Treatment with 4-phenylbutyric acid, a chemical protein chaperone that reduces ER stress, restored vascular endothelial cell expression of adhesion molecules and protected against LPS-induced acute lung injury in diet-induced obese mice. Our work indicates that fatty acids in obese serum induce ER stress in the pulmonary endothelium, leading to pulmonary endothelial cell dysfunction. Our work suggests that reducing protein load in the ER of pulmonary endothelial cells might protect against acute respiratory distress syndrome in obese individuals.

Lipid Injectable Emulsions: 2006

Lipid injectable emulsions are an essential source of fatty acids, as well as a daily source of calories. They have been used in the clinical setting for almost 40 years, but despite this, there are no established official standards governing pharmaceutical quality. After 15 years of development, the United States Pharmacopeia (USP), which writes such standards for all FDA-approved pharmaceuticals, is poised to adopt an official monograph for lipid injectable emulsions that sets pharmaceutical requirements on all manufacturers placing limits on pH, free fatty acid concentrations and globule size (both mean droplet size and the population of large fat globules larger than 5 micrometers). Recent animal data has shown pathophysiologic changes in vital organs for lipids that fall outside the USP-proposed globule size limits. From a clinical perspective, newer lipid injectable emulsions show great promise in certain patient settings, most notably in the intensive care unit in both adults and infants. The clinical use of alternative oils, such as medium-chain triglycerides, fish oil and olive oil show benefits over conventional soybean oil formulations. In adults, for example, the administration of omega-fatty acids via soybean oil-based lipids produces a heightened inflammatory response via production of 2-series prostaglandins, whereas substitution of a portion of the lipid with omega-3 fatty acids via fish oil can favorably dampen the inflammatory response. In infants, for example, substitution of soybean oil with fish oil has recently been shown to reverse parenteral nutrition-associated liver disease. These advances should lead to safer infusion therapy in patients receiving lipid injectable emulsions.

The Acute Respiratory Distress Syndrome: Role of Nutritional Modulation of Inflammation Through Dietary Lipids

The acute respiratory distress syndrome (ARDS) is the most serious form of acute hypoxic respiratory failure. ARDS represents the expression of an acute, diffuse, inflammatory process in the lungs consequent to a variety of infectious and noninfectious conditions. It is characterized pathologically by damage to pulmonary epithelial and endothelial cells, with subsequent alveolar-capillary leak and exudative pulmonary edema. The main clinical features of ARDS include rapid onset of dyspnea, severe defects in gas exchange, and imaging studies demonstrating diffuse pulmonary infiltrates. The role of nutrition in the management of ARDS has traditionally been supportive. Recent research has demonstrated the potential of certain dietary oils (eg, fish oil, borage oil) to modulate pulmonary inflammation, thereby improving lung compliance and oxygenation, and reducing time on mechanical ventilation. This article reviews the alterations in the immune response that underlie ARDS, discusses the physiology of dietary oils as immunonutrients, summarizes animal and human studies that explore the therapeutic effects of dietary oils, and provides clinical recommendations for their use.

Systematic review of clinical adverse events reported after acute intravenous lipid emulsion administration

BACKGROUND

Intravenous lipid emulsions (ILEs) were initially developed to provide parenteral nutrition. In recent years, ILE has emerged as a treatment for poisoning by local anesthetics and various other drugs. The dosing regimen for the clinical toxicology indications differs significantly from those used for parenteral nutrition. The evidence on the efficacy of ILE to reverse acute toxicity of diverse substances consists mainly of case reports and animal experiments. Adverse events to ILE are important to consider when clinicians need to make a risk/benefit analysis for this therapy.

METHODS

Multiple publication databases were searched to identify reports of adverse effects associated with acute ILE administration for either treatment of acute poisoning or parenteral nutrition. Articles were selected based on pre-defined criteria to reflect acute use of ILE. Experimental studies and reports of adverse effects as a complication of long-term therapy exceeding 14 days were excluded.

RESULTS

The search identified 789 full-text articles, of which 114 met the study criteria. 27 were animal studies, and 87 were human studies. The adverse effects associated with acute ILE administration included acute kidney injury, cardiac arrest, ventilation perfusion mismatch, acute lung injury, venous thromboembolism, hypersensitivity, fat embolism, fat overload syndrome, pancreatitis, extracorporeal circulation machine circuit obstruction, allergic reaction, and increased susceptibility to infection.

CONCLUSION

The emerging use of ILE administration in clinical toxicology warrants careful attention to its potential adverse effects. The dosing regimen and context of administration leading to the adverse events documented in this review are not generalizable to all clinical toxicology scenarios. Adverse effects seem to be proportional to the rate of infusion as well as total dose received. Further safety studies in humans and reporting of adverse events associated with ILE administration at the doses advocated in current clinical toxicology literature are needed.

Prolonged Laboratory Interference After Administration of Intravenous Lipid Emulsion Therapy

BACKGROUND

Pancreatitis and laboratory interference are rarely reported complications of intravenous lipid emulsion (ILE) therapy. We report a case of significant laboratory interference after ILE administration.

CASE REPORT

A 43-year-old female was admitted to the hospital after an unwitnessed ingestion of propranolol, tramadol, zolpidem, and alprazolam. She was intubated and treated with intravenous normal saline, insulin/glucose, and norepinephrine infusions due to hypotension. Two bolus doses and one maintenance dose of 20 % ILE were administered. Beginning approximately 2 h after ILE administration, laboratory assays were unable to be performed due to the presence of lipemia. The patient developed refractory hypotension and was transferred to a tertiary care center. Upon admission to the ICU, the patient received one additional bolus of 20 % ILE. Laboratory assays were again attempted but were unable to be adequately performed due to a pinkish-white discoloration of the patient's blood. Percutaneous femoral extracorporeal membrane oxygenation (ECMO) was initiated, but laboratory interference noted with the arterial blood gas analyzer prevented the analysis of oxygenation. The patient's hemodynamic condition did not improve; she expired 31 h after initial admission.

CASE DISCUSSION

In one previous report, centrifugation was effective in removing more than 90 % of glycerol-banked triglycerides, thus minimizing lipid interference with laboratory assays. We noted persistent laboratory interference for more than 20 h after ILE administration, despite ultracentrifugation of specimens.

CONCLUSION

Clinicians should be aware that ILE administration may cause significant and prolonged interference with laboratory assays, which may affect the monitoring of critically ill patients.

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.

Alternative lipid emulsions versus pure soy oil based lipid emulsions for parenterally fed preterm infants

BACKGROUND

The pure soybean oil based lipid emulsions (S-LE) conventionally used for parenteral nutrition (PN) in preterm infants have high polyunsaturated fatty acid (PUFA) content. The newer lipid emulsions (LE) from alternative lipid sources with reduced PUFA content may improve clinical outcomes in preterm infants.

OBJECTIVES

To determine the safety and efficacy of the newer alternative LE compared with the conventional S-LE for PN in preterm infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group (CNRG) to search the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 7), MEDLINE (1946 to 31 July 2015), EMBASE (1947 to 31 July 2015), CINAHL (1982 to 31 July 2015), Web of Science (31 July 2015), conference proceedings, trial registries (clinicaltrials.gov, controlled-trials.com, WHO's ICTRP), and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials in preterm infants (< 37 weeks), comparing newer alternative LE with S-LE.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of the CNRG. We assessed the quality of evidence for important outcomes using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, in addition to reporting the conventional statistical significance of results.

MAIN RESULTS

Fifteen studies (N = 979 infants) are included in this review. Alternative LE including medium chain triglycerides/long chain triglycerides (MCT/LCT) LE (3 studies; n = 108), MCT-olive-fish-soy oil-LE (MOFS-LE; 7 studies; n = 469), MCT-fish-soy oil-LE (MFS-LE; 1 study; n = 60), olive-soy oil-LE (OS-LE; 7 studies; n = 406), and borage-soy oil-LE (BS-LE; 1 study; n = 34) were compared with S-LE. The different LE were also considered together to compare 'all fish oil containing-LE' versus S-LE (7 studies; n = 499) and 'all alternative LE' versus S-LE (15 studies; n = 979). Some studies had multiple intervention arms and were included in more than one comparison. No study compared pure fish oil-LE or structured-LE to S-LE.The GRADE quality of evidence (GRADE QoE) ranged from 'low' to 'very low.' Evidence came mostly from small single centre studies, many focusing on biochemical aspects as their primary outcomes, with optimal information size not achieved for the important clinical outcomes in any comparison.In the primary outcomes of the review there was a pooled effect towards decreased bronchopulmonary dysplasia (BPD) in OS-LE vs S-LE (4 studies, n = 261) not reaching statistical significance (typical risk ratio (RR) 0.69, 95% confidence interval (CI) 0.46 to 1.04, I² = 32%; typical risk difference (RD) -0.08, 95% CI -0.17 to 0.00, I² = 76%; GRADE QoE: 'very low'). No difference in BPD was observed in any other comparison. There were no statistically significant differences in the primary outcomes of death, growth rate (g/kg/day) or days to regain birth weight in any comparison.Retinopathy of prematurity (ROP) stage 1-2 was reported to be statistically significantly lower in one single centre study (n = 80) in the MOFS-LE group compared with the S-LE group (1/40 vs 12/40, respectively; RR 0.08, 95% CI 0.01 to 0.61; RD -0.27, 95% CI -0.43 to -0.12; number needed to benefit (NNTB) 4, 95% CI 2 to 8). However there were no statistically significant differences in the secondary outcome of ROP ≥ stage 3 in any of the individual studies or in any comparison (GRADE QoE: 'low' to 'very low'). No other study reported on ROP stages 1 and 2 separately.There were no statistically significant differences in the secondary outcomes of sepsis, PN associated liver disease (PNALD)/cholestasis, ventilation duration, necrotising enterocolitis (NEC) ≥ stage 2, jaundice requiring treatment, intraventricular haemorrhage grade III-IV, periventricular leukomalacia (PVL), patent ductus arteriosus (PDA), hypertriglyceridaemia, and hyperglycaemia in any comparison.No study reported on neurodevelopmental outcomes or essential fatty acid deficiency.

AUTHORS' CONCLUSIONS

All lipid emulsions in this review appeared to be safe and were well tolerated in preterm infants. Compared with the pure soy oil based LE, use of MOFS-LE was associated with a decrease in the early stages (1-2) of ROP in one study. However there were no statistically significant differences in clinically important outcomes including death, growth, BPD, sepsis, ROP ≥ stage 3, and PNALD with the use of newer alternative LE versus the conventional pure soy oil based LE (GRADE QoE ranged from 'low' to 'very low'). Currently there is insufficient evidence to recommend any alternative LE over S-LE or vice versa in preterm infants.Larger randomised studies focusing on important clinical outcomes, targeting specific 'at risk' population subgroups (e.g. extreme prematurity, long term PN, etc), and exploring the effect of different proportions of lipid constituents are required to evaluate the effectiveness of newer lipid emulsions compared with the conventional pure soy based LE in preterm infants.

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.

Complications following antidotal use of intravenous lipid emulsion therapy

The primary objective is to identify and describe the complications associated with the use of intravenous lipid emulsion (ILE) therapy as an antidote for lipophilic drug toxicity. This study is a retrospective chart review of patients treated with ILE at two academic medical centers between 2005 and 2012. Based on previously reported complications, we hypothesized that pancreatitis, ARDS, and lipemia-induced laboratory interference might occur. Clinical definitions of these complications were defined a priori. Subjects treated with ILE who did not develop at least one complication were excluded. A total of nine patients were treated with ILE during the study period, six of whom experienced potential complications as a result of the ILE. Two patients developed pancreatitis, and four patients had lipemia-induced interference of interpretation of laboratory studies, despite ultracentrifugation. Laboratory interference precluded one patient from being an organ donor. Three patients developed ARDS; although temporally associated, a causal relationship between ILE and the development of ARDS cannot be clearly established. As ILE is increasingly used for less severe cases of drug toxicity, clinicians should be aware of potential complications associated with its use. A risk-benefit assessment for the use of ILE should be implemented on a case-by-case basis.

Evaluating the effects and safety of intravenous lipid emulsion on haloperidol-induced neurotoxicity in rabbit

There are many reports on the effect of intravenous lipid emulsion (ILE) as an antidote in drugs related toxicities. We determined the effects of ILE on neurotoxicity of haloperidol (HA), a highly lipophilic antipsychotic, as a model of antipsychotics poisoning. We used six groups of five male rabbits. Two groups received distilled water intravenously followed by infusions of either 18 mL/kg of normal saline or ILE 20%, after 30 minutes. The third group received 18 mL/kg of normal saline after HA (2.6 mg/kg) administration. The three other groups received ILE 20% solution (6, 12, and 18 mL/kg) following HA injection. Catalepsy scores, temperature, pupil size, and mortality rate were measured at 0, 0.5, 1, 2, 3, 4, 8, and 24 hours after HA administration began. Blood and tissue samples were taken from all animals at 24 hours or at death time for biochemical, cell count, and pathological studies. ILE reversed cataleptic scores, miotic pupils, and hypothermia of HA intoxication much faster than normal saline (P < 0.001). Biochemical complications and mortality rate of the animals were significantly higher in the HA + 18 mL/Kg ILE group. ILE reversed sings of HA neurotoxicity; however, synergistic effect of high dose of ILE and HA increased complications and mortality.

Immunomodulation by fish-oil containing lipid emulsions in murine acute respiratory distress syndrome

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is a major cause of mortality in intensive care units. Patients with ARDS often require parenteral nutrition with lipid emulsions as essential components. Besides being an energy supply, these lipid emulsions might display differential modulatory effects on lung integrity and inflammation.

METHODS

In a pre-emptive strategy, we investigated the impact of three different intravenously infused lipid emulsions on lung morphology, leukocyte invasion, protein leakage and cytokines in a murine model of ARDS. Mice received an infusion of normal saline solution, a pure long-chain triglycerides (LCT) emulsion, a medium-chain triglycerides (MCT) containing mixed emulsion (LCT/MCT), or a fish oil (FO) containing mixed emulsion (LCT/MCT/FO) before lipopolysaccharide (LPS) challenge.

RESULTS

Mice pre-infused with fish oil-containing lipid emulsion showed decreased leukocyte invasion, protein leakage, myeloperoxidase activity, and cytokine production in their alveolar space after LPS challenge compared to mice receiving LCT or LCT/MCT. In line with these findings, lung morphology assessed by histological staining after LPS-induced lung injury improved faster in the LCT/MCT/FO group. Concerning the above mentioned parameters, no significant difference was observed between mice infused with LCT or the combination of LCT and MCT.

CONCLUSION

Fish oil-containing lipid emulsions might exert anti-inflammatory and pro-resolving effects in the murine model of acute lung injury. Partial replacement of n-6 fatty acids with n-3 fatty acids may thus be of benefit for critically ill patients at risk for ARDS which require parenteral nutrition.

Potential influence of intravenous lipids on the outcomes of acute pancreatitis

Parenteral nutrition (PN) has been associated with a higher rate of adverse outcomes compared with enteral feeding in patients with acute pancreatitis (AP). However, PN may be necessary when feeding via the enteral route is poorly tolerated or impossible, and PN is recommended as a second-line nutrition therapy in AP. Intravenous (IV) lipids are commonly used as a part of PN in patients with AP. While the adverse outcomes related to the use of PN in AP have commonly been attributed to infectious complications, data suggest that the unsaturated fatty acids in the triglycerides used in IV lipids may contribute to the development of organ failure. We discuss the clinical and experimental data on this issue and the alternative lipid emulsions that are being studied.

A randomized controlled trial investigating the effects of parenteral fish oil on survival outcomes in critically ill patients with sepsis: a pilot study

INTRODUCTION

Death from sepsis in the intensive care unit (ITU) is frequently preceded by the development of multiple organ failure as a result of uncontrolled inflammation. Treatment with ω-3 has been demonstrated to attenuate the effects of uncontrolled inflammation and may be clinically beneficial.

METHOD

A randomized control trial investigating the effects of parenteral ω-3 was carried out. Consecutive patients diagnosed with sepsis were entered into the study and randomized to receive either parenteral ω-3 or standard medical care only. The primary outcome measure was a reduction in organ dysfunction using the Sequential Organ Failure Assessment (SOFA) score as a surrogate marker. The secondary outcome measures were mortality, length of stay, mean C-reactive protein (CRP), and days free of organ dysfunction/failure.

RESULTS

Sixty patients were included in the study. The baseline demographics were matched for the two cohorts. Patients treated with parenteral ω-3 were associated with a significant reduction in new organ dysfunction (Δ-SOFA 2.2 ± 2.2 vs. 1.0 ± 1.5, P = .005 and maximum-SOFA 10.1 ± 4.2 vs. 8.1 ± 3.2, P = .041) and maximum CRP (186.7 ± 78 vs. 141.5 ± 62.6, P = .019). There was no significant reduction in the length of stay between cohorts. Patients treated with ω-3 in the strata of less severe sepsis had a significant reduction in mortality (P = .042).

CONCLUSION

The treatment of critically ill septic patients with parenteral ω-3 is safe. It is associated with a significant reduction in organ dysfunction. It may be associated with a reduction in mortality in patients with less severe sepsis.

Clinical experience with intravenous lipid emulsion for drug-induced cardiovascular collapse

Intravenous lipid emulsion (ILE) is an emerging therapy for refractory cardiotoxicity due to lipid-soluble drugs. The purpose of this study was to assess survival to hospital discharge, effects on hemodynamic parameters, and adverse event occurrence for patients who were treated with ILE as part of the resuscitative effort for drug-induced cardiotoxicity. This is a multicenter retrospective chart review of inpatients at three tertiary referral medical centers receiving ILE for drug-induced cardiotoxicity between November 2007 and March 2009. Nine cases with drug-induced cardiovascular collapse, defined as cardiac arrest or refractory shock, were selected for review if patients received either bolus or infusion of ILE in any combination. No interventions were done. The main outcome measures were survival to hospital discharge, effect on hemodynamic parameters, and adverse event. Hemodynamic vital signs (heart rate, systolic blood pressure, diastolic blood pressure, calculated mean arterial pressure [MAP]) were measured before administration of ILE and up to five measurements (if available) were recorded after administration of ILE. Attribution of adverse events was determined by assignment of Naranjo adverse drug reaction (ADR) likelihood score (3) with adjudication of three medical toxicologists; disagreements were settled by majority consensus. Of nine cases identified based on inclusion criteria (three cardiac arrest, six refractory shock), five (55%) survived to hospital discharge. ILE regimens were bolus alone in five patients and bolus plus infusion in four patients. Hemodynamic trends in response to ILE demonstrated no difference in MAP immediately pre- and post-administration of ILE (p = NS). Administration of infusion (versus boluses alone) did not demonstrate a statistically significant improvement in MAP. Adverse events due to ILE therapy that were categorized as "possible" or "probable" based on Naranjo scores included lipemia, digit amputation, lung injury, renal failure, and deep venous thrombosis. ILE administered to patients with drug-induced cardiovascular collapse was associated with 55% survival but with clinically significant adverse effects. At this time, ILE should be restricted to cardiotoxicity involving cardiac arrest or refractory shock until further prospective studies can better evaluate risks and benefits of ILE therapy.

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

Background

The use of lipid emulsions has been associated with changes in lung function and gas exchange which may be mediated by biologically active metabolites derived from arachidonic acid. The type and quantity of the lipid emulsions used could modulate this response, which is mediated by the eicosanoids. This study investigates the use of omega-3 fatty acid-enriched lipid emulsions in ARDS patients and their effects on eicosanoid values.

Methods

Prospective, randomized, double-blind, parallel group study carried out at the Intensive Medicine Department of Vall d'Hebron University Hospital (Barcelona-Spain). We studied 16 consecutive patients with ARDS and intolerance to enteral nutrition (14 men; age: 58 ± 13 years; APACHE II score 17.8 ± 2.3; Lung Injury Score: 3.1 ± 0.5; baseline PaO₂/FiO₂ ratio: 149 ± 40). Patients were randomized into two groups: Group A (n = 8) received the study emulsion Lipoplus^® 20%, B. Braun Medical (50% MCT, 40% LCT, 10% fish oil (FO)); Group B (n = 8) received the control emulsion Intralipid^® Fresenius Kabi (100% LCT). Lipid emulsions were administered for 12 h at a dose of 0.12 g/kg/h. We measured LTB₄, TXB₂, and 6-keto prostaglandin F_1α values at baseline [immediately before the administration of the lipid emulsions (T-0)], at the end of the administration (T-12) and 24 hours after the beginning of the infusion (T 24) in arterial and mixed venous blood samples.

Results

In group A (FO) LTB₄, TXB₂, 6-keto prostaglandin F_1α levels fell during omega-3 administration (T12). After discontinuation (T24), levels of inflammatory markers (both systemic and pulmonary) behaved erratically. In group B (LCT) all systemic and pulmonary mediators increased during lipid administration and returned to baseline levels after discontinuation, but the differences did not reach statistical significance. There was a clear interaction between the treatment in group A (fish oil) and changes in LTB₄ over time.

Conclusions

Infusion of lipids enriched with omega-3 fatty acids produces significant short- term changes in eicosanoid values, which may be accompanied by an immunomodulatory effect.

Trial registration

ISRCTN63673813.

Alterations in adipose tissue during critical illness: An adaptive and protective response?

RATIONALE

Critical illness is characterized by lean tissue wasting, whereas adipose tissue is preserved. Overweight and obese critically ill patients may have a lower risk of death than lean patients, suggestive of a protective role for adipose tissue during illness.

OBJECTIVES

To investigate whether adipose tissue could protectively respond to critical illness by storing potentially toxic metabolites, such as excess circulating glucose and triglycerides.

METHODS

We studied adipose tissue morphology and metabolic activity markers in postmortem biopsies of 61 critically ill patients and 20 matched control subjects. Adipose morphology was also studied in in vivo biopsies of 27 patients and in a rabbit model of critical illness (n = 22).

MEASUREMENTS AND MAIN RESULTS

Adipose tissue from critically ill patients revealed a higher number and a smaller size of adipocytes and increased preadipocyte marker levels as compared with control subjects. Virtually all adipose biopsies from critically ill patients displayed positive macrophage staining. The animal model demonstrated similar changes. Glucose transporter levels and glucose content were increased. Glucokinase expression was up-regulated, whereas glycogen and glucose-6-phosphate levels were low. Acetyl CoA carboxylase protein and fatty acid synthase activity were increased. Hormone-sensitive lipase activity was not altered, whereas lipoprotein lipase activity was increased. A substantially increased AMP-activated protein kinase activity may play a crucial role.

CONCLUSIONS

Postmortem adipose tissue biopsies from critically ill patients displayed a larger number of small adipocytes in response to critical illness, revealing an increased ability to take up circulating glucose and triglycerides. Similar morphologic changes were present in vivo. Such changes may render adipose tissue biologically active as a functional storage depot for potentially toxic metabolites, thereby contributing to survival.

Intravenous lipid emulsion as antidote beyond local anesthetic toxicity: a systematic review

OBJECTIVES

The objective was to asses the efficacy of lipid emulsion as antidotal therapy outside the accepted setting of local anesthetic toxicity.

METHODS

Literature was accessed through PubMed, OVID (1966-February 2009), and EMBASE (1947-February 2009) using the search terms "intravenous" AND ["fat emulsion" OR "lipid emulsion" OR "Intralipid"] AND ["toxicity" OR "resuscitation" OR "rescue" OR "arrest" OR "antidote"]. Additional author and conference publication searches were undertaken. Publications describing the use of lipid emulsion as antidotal treatment in animals or humans were included.

RESULTS

Fourteen animal studies, one human study, and four case reports were identified. In animal models, intravenous lipid emulsion (ILE) has resulted in amelioration of toxicity associated with cyclic antidepressants, verapamil, propranolol, and thiopentone. Administration in human cases has resulted in successful resuscitation from combined bupropion/lamotrigine-induced cardiac arrest, reversal of sertraline/quetiapine-induced coma, and amelioration of verapamil- and beta blocker-induced shock.

CONCLUSIONS

Management of overdose with highly lipophilic cardiotoxic medications should proceed in accord with established antidotal guidelines and early poisons center consultation. Data from animal experiments and human cases are limited, but suggestive that ILE may be helpful in potentially lethal cardiotoxicity or developed cardiac arrest attributable to such agents. Use of lipid emulsion as antidote remains a nascent field warranting further preclinical study and systematic reporting of human cases of use.

Formulation of multifunctional oil-in-water nanosized emulsions for active and passive targeting of drugs to otherwise inaccessible internal organs of the human body

Oil-in-water (o/w) type nanosized emulsions (NE) have been widely investigated as vehicles/carrier for the formulation and delivery of drugs with a broad range of applications. A comprehensive summary is presented on how to formulate the multifunctional o/w NE for active and passive targeting of drugs to otherwise inaccessible internal organs of the human body. The NE is classified into three generations based on its development over the last couple of decades to make ultimately a better colloidal carrier for a target site within the internal and external organs/parts of the body, thus allowing site-specific drug delivery and/or enhanced drug absorption. The third generation NE has tremendous application for drug absorption enhancement and for 'ferrying' compounds across cell membranes in comparison to its first and second generation counterparts. Furthermore, the third generation NE provides an interesting opportunity for use as drug delivery vehicles for numerous therapeutics that can range in size from small molecules to macromolecules.

Phospholipase A2 subclasses in acute respiratory distress syndrome

Phospholipases A2 (PLA2) catalyse the cleavage of fatty acids esterified at the sn-2 position of glycerophospholipids. In acute lung injury-acute respiratory distress syndrome (ALI-ARDS) several distinct isoenzymes appear in lung cells and fluid. Some are capable to trigger molecular events leading to enhanced inflammation and lung damage and others have a role in lung surfactant recycling preserving lung function: Secreted forms (groups sPLA2-IIA, -V, -X) can directly hydrolyze surfactant phospholipids. Cytosolic PLA2 (cPLA2-IVA) requiring Ca2+ has a preference for arachidonate, the precursor of eicosanoids which participate in the inflammatory response in the lung. Ca(2+)-independent intracellular PLA2s (iPLA2) take part in surfactant phospholipids turnover within alveolar cells. Acidic Ca(2+)-independent PLA2 (aiPLA2), of lysosomal origin, has additionally antioxidant properties, (peroxiredoxin VI activity), and participates in the formation of dipalmitoyl-phosphatidylcholine in lung surfactant. PAF-AH degrades PAF, a potent mediator of inflammation, and oxidatively fragmented phospholipids but also leads to toxic metabolites. Therefore, the regulation of PLA2 isoforms could be a valuable approach for ARDS treatment.

A 6-year review of total parenteral nutrition use and association with late-onset acute respiratory distress syndrome among ventilated trauma victims

AIM

To establish whether total parenteral nutrition (TPN) for ventilated trauma victims is associated with late-onset acute respiratory distress syndrome (ARDS) independent of ventilation and transfusion parameters.

METHOD

Intensive care unit data over 6 years from a level I centre regarding all trauma victims > or = 16 years old who underwent mechanical ventilation within the first 48 h of admission were examined. Patients were prospectively followed for late ARDS. Variables were examined for significant changes over time and independent associations with late ARDS were determined.

RESULTS

Of 2346 eligible patients among whom 404 (17.2%) were exposed to TPN, 192 (8.2%) met criteria for late ARDS. The incidence of late ARDS among those exposed to TPN was 28.7% (116/404) compared with 3.9% (76/1942) among those not so exposed. Adjustments for potential confounding associated risk factors were made.

CONCLUSIONS

TPN administration is independently associated with late ARDS, and its use among critically ill trauma victims should be carefully scrutinised.

Role of lipid emulsion administration in acute lung injury during liver transplant rejection: a case report

We report the case of a 58-year-old woman who developed rejection and acute lung injury 10 days after an orthotopic liver transplantation while receiving total parenteral nutrition. Examination of bronchoalveolar lavage fluid revealed large lipid droplets in the alveolar macrophages. Intensification of the immunosuppressive therapy attenuated the liver allograft rejection followed by resolution of lung injury.