Early fish oil supplementation and organ failure in patients with septic shock from abdominal infections: a propensity-matched cohort study

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

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

Fish Oil-Containing Lipid Emulsions in Adult Parenteral Nutrition: A Review of the Evidence

BACKGROUND

There is evidence from laboratory and animal studies that fish oil-containing intravenous lipid emulsions (FOC-IVLEs) have a beneficial effect on inflammation and the immune response, suggesting a possible clinical benefit. Clinical studies of FOC-IVLEs have reported mixed results. The aim of this review is to present findings from recent randomized controlled clinical trials and other quality clinical studies investigating the effects of administering intravenous fish oil alone or as part of a multilipid emulsion and to examine the quality of these studies in an objective, evidence-based manner.

METHODS

Studies comparing FOC-IVLEs with other IVLEs in adults were included. Thirty-four clinical studies were evaluated: 19 investigated levels of inflammatory and immune markers as an endpoint; 13 investigated rates of infection or sepsis; 3 investigated clinical outcomes in septic patients; and 29 investigated general clinical outcomes.

RESULTS

There was conflicting evidence for a beneficial effect of fish oil on levels of inflammatory and immune markers and some evidence that fish oil decreased the rate of postoperative atrial fibrillation. Studies generally reported few statistical differences in clinical outcomes and rates of infection and sepsis with FOC-IVLEs as compared with other IVLEs. The quality of reporting was generally poor, and the presented evidence for comparisons between FOC-IVLEs and other IVLEs was inconclusive or weak.

CONCLUSIONS

There is very little high-quality evidence that FOC-IVLEs have a more beneficial effect than other IVLEs on clinical outcomes in adult patients.

Omega-3 Fish Oil Reduces Mortality Due to Severe Sepsis with Acute Gastrointestinal Injury Grade III

Background:

Sepsis plays an important role in acute gastrointestinal injury (AGI). Our research was designed to determine the effects of omega-3 fish oil (FO) in patients suffering from severe sepsis combined with AGI III, and the ability of FO to modulate immune function.

Methods:

Seventy-eight patients diagnosed with severe sepsis with AGI III and a need for mechanical ventilation were randomized to two groups. In the FO group, 50 g of long chain fatty acid soybean oil (n = 6) and 10 g of FO (n = 3) were administered as total parenteral nutrition (TPN). The control group was treated with 50 g of long chain fatty acid soybean oil without addition of FO to TPN.

Results:

At baseline, there were no significant differences between the two groups. The 60-day mortality was lower in the FO group. Multiple factor logistic regression analysis revealed that intra-abdominal pressure (IAP) and abdominal infection were correlated with the FO intervention. The patients with abdominal infection demonstrated a lower mortality rate, fewer CD3 T lymphocytes, and fewer helper/inducer T lymphocytes in the FO group compared with the control group. After 7 days, the Marshall Score was lower in the FO group than in the control group.

Conclusion:

FO has positive effects in terms of improving the long-term prognosis of patients with severe sepsis with AGI III. Patients with a high IAP and abdominal infection might experience greater benefit from FO. This effect might be due, in part, to immunomodulation.

SUMMARY

Fish oil (FO) has positive effects in terms of improving the long-term prognosis of patients with severe sepsis with acute gastrointestinal injury Grade III

Patients with a high intra-abdominal pressure and abdominal infection might experience greater benefit from FO

This effect might be due, in part, to immunomodulation.

Abbreviations used: AGI: Acute gastrointestinal injury; FO: Fish oil; TPN: Total parenteral nutrition; IAP: Intra-abdominal pressure; ICU: Intensive Care Unit; MODS: Multiple organ dysfunction syndrome; TLR4: Toll-like receptor 4; DNR: Do Not Resuscitate; WGAP: Working Group of Abdominal Problem; EN: Enteral nutrition; BP: Low blood pressure; CRI: Catheter-related infection; PBS: Phosphate-buffered saline; ELFA: Enzyme-linked fluorescent assay; SD: Standard deviation; PUFAs: Polyunsaturated fatty acids; EPA: Eicosapentenoic acid; DHA: Docosahexaenoic acid.

Single-blinded, randomized, and controlled clinical trial evaluating the effects of Omega-3 fatty acids among septic patients with intestinal dysfunction: A pilot study

Sepsis is a systemic inflammatory reaction, which is aggravated by aspects of the immune response that are thought to be inhibited by Omega-3 fatty acids. The aim of the present study was to determine if Omega-3 fatty acid could modulate immunological function and improve survival rate among septic patients with intestinal dysfunction. A total of 48 mechanically ventilated patients with intestinal dysfunction were included in this prospective, randomized and single-blind clinical study. Patients were randomly divided into control (group A) and treatment groups (group B). The treatment protocol for all the participants followed the Sepsis Survival Campaign guidelines, and group B received total parenteral nutrition containing 100 ml of Omega-3 fatty acids (containing 10 g refined fish oil) per day in addition to the standard treatment applied in group A. Group B had a significantly lower mortality rate compared with group A (12.5 vs. 41.7%, P<0.05) during the 28-day follow-up. Group B also had lower Acute Physiology and Chronic Health Evaluation II scores (P<0.05) and lower Marshall scores (P<0.05) at day 7. In addition, group B had a higher ratio of T helper to inducer lymphocytes as well as a higher ratio of CD4 to CD8 lymphocytes (P<0.01 for both) than group A. It was concluded that Omega-3 fatty acids improved T helper/inducer and CD4/CD8 ratios, and may have reduced mortality, among septic patients with intestinal dysfunction.

Krill Oil-In-Water Emulsion Protects against Lipopolysaccharide-Induced Proinflammatory Activation of Macrophages In Vitro

Background: Parenteral nutrition is often a mandatory therapeutic strategy for cases of septicemia. Likewise, therapeutic application of anti-oxidants, anti-inflammatory therapy, and endotoxin lowering, by removal or inactivation, might be beneficial to ameliorate the systemic inflammatory response during the acute phases of critical illness. Concerning anti-inflammatory properties in this setting, omega-3 fatty acids of marine origin have been frequently described. This study investigated the anti-inflammatory and LPS-inactivating properties of krill oil (KO)-in-water emulsion in human macrophages in vitro. Materials and Methods: Differentiated THP-1 macrophages were activated using specific ultrapure-LPS that binds only on the toll-like receptor 4 (TLR4) in order to determine the inhibitory properties of the KO emulsion on the LPS-binding capacity, and the subsequent release of TNF-α. Results: KO emulsion inhibited the macrophage binding of LPS to the TLR4 by 50% (at 12.5 µg/mL) and 75% (at 25 µg/mL), whereas, at 50 µg/mL, completely abolished the LPS binding. Moreover, KO (12.5 µg/mL, 25 µg/mL, or 50 µg/mL) also inhibited (30%, 40%, or 75%, respectively) the TNF-α release after activation with 0.01 µg/mL LPS in comparison with LPS treatment alone. Conclusion: KO emulsion influences the LPS-induced pro-inflammatory activation of macrophages, possibly due to inactivation of the LPS binding capacity.

Innate immunity gene expression changes in critically ill patients with sepsis and disease-related malnutrition

The aim of this study was an attempt to determine whether the expression of genes involved in innate antibacterial response (TL R2, NOD 1, TRAF6, HMGB 1 and Hsp70) in peripheral blood leukocytes in critically ill patients, may undergo significant changes depending on the severity of the infection and the degree of malnutrition. The study was performed in a group of 128 patients with infections treated in the intensive care and surgical ward. In 103/80.5% of patients, infections had a severe course (sepsis, severe sepsis, septic shock, mechanical ventilation of the lungs). Clinical monitoring included diagnosis of severe infection (according to the criteria of the ACC P/SCC M), assessment of severity of the patient condition and risk of death (APACHE II and SAPS II), nutritional assessment (NRS 2002 and SGA scales) and the observation of the early results of treatment. Gene expression at the mRNA level was analyzed by real-time PCR. The results of the present study indicate that in critically ill patients treated in the IC U there are significant disturbances in the expression of genes associated with innate antimicrobial immunity, which may have a significant impact on the clinical outcome. The expression of these genes varies depending on the severity of the patient condition, severity of infection and nutritional status. Expression disorders of genes belonging to innate antimicrobial immunity should be diagnosed as early as possible, monitored during the treatment and taken into account during early therapeutic treatment (including early nutrition to support the functions of immune cells).

Pros and cons of feeding the septic intensive care unit patient

Sepsis is a common disease seen in critically ill patients. Many patients with sepsis are unable to provide nutrition for themselves, and therefore initiating artificial nutrition has become part of routine care for these patients. However, studies investigating the optimal route, composition, volume, and duration of nutrition in critically ill patients with sepsis are lacking. The best recommendations have to be extrapolated from studies in heterogeneous populations of critically ill patients or in those with syndromes such as acute lung injury or acute respiratory distress syndrome (ARDS) where sepsis is a common predisposing etiology. In this review, we summarize pertinent studies that inform clinical practice on providing artificial nutrition to critically ill patients with severe sepsis and make recommendations as to how these studies influence clinical care of these patients.

Do the observational studies using propensity score analysis agree with randomized controlled trials in the area of sepsis?

BACKGROUND AND OBJECTIVES

Sepsis is a leading cause of mortality and morbidity in the intensive care unit, and many studies have been conducted aiming to improve its outcome. Randomized controlled trials (RCTs) and observational studies using propensity score (PS) method are commonly used for this purpose. However, the agreement between these two major methodological designs has never been investigated in this specific area. The present study aimed to compare the effect sizes between RCTs and PS-based studies.

METHODS

Electronic databases including Pubmed, Scopus, and EBSCO were searched to obtain PS-based studies in the area of sepsis. The studies were matched to RCTs or systematic reviews and meta-analysis in terms of population, intervention, control, and outcome. When there were multiple PS-based studies or RCTs in one area, the effect sizes were pooled by using random-effects model and inverse variance method. The comparisons were performed by using differences in the effect size.

RESULTS

A total of 8 topics were identified fulfilling the criterion that at least 1 pair of RCT and PS-based study could be matched. The interventions included activated protein C, low-dose steroid, antithrombin III, combination antibiotic therapy, fish oil supplementation, statin, etomidate for intubation, and recombinant human soluble thrombomodulin. The effect sizes were statistically different between RCTs and PS-based studies in most circumstances (6/8). The pooled mean difference in effect sizes was -0.16 (95% confidence interval, -0.33 to 0.01), indicating a trend towards larger treatment effect in PS studies than in RCTs. The result remains unaltered by restricting to RCTs and PS studies with the largest sample sizes.

CONCLUSION

Our study shows that PS studies tend to report larger treatment effect than RCTs in the field of sepsis, indicating the difference between efficacy trials and effectiveness studies.

Observational studies using propensity score analysis underestimated the effect sizes in critical care medicine

BACKGROUND AND OBJECTIVE

Propensity score (PS) analysis has been increasingly used in critical care medicine; however, its validation has not been systematically investigated. The present study aimed to compare effect sizes in PS-based observational studies vs. randomized controlled trials (RCTs) (or meta-analysis of RCTs).

METHODS

Critical care observational studies using PS were systematically searched in PubMed from inception to April 2013. Identified PS-based studies were matched to one or more RCTs in terms of population, intervention, comparison, and outcome. The effect sizes of experimental treatments were compared for PS-based studies vs. RCTs (or meta-analysis of RCTs) with sign test. Furthermore, ratio of odds ratio (ROR) was calculated from the interaction term of treatment × study type in a logistic regression model. A ROR < 1 indicates greater benefit for experimental treatment in RCTs compared with PS-based studies. RORs of each comparison were pooled by using meta-analytic approach with random-effects model.

RESULTS

A total of 20 PS-based studies were identified and matched to RCTs. Twelve of the 20 comparisons showed greater beneficial effect for experimental treatment in RCTs than that in PS-based studies (sign test P = 0.503). The difference was statistically significant in four comparisons. ROR can be calculated from 13 comparisons, of which four showed significantly greater beneficial effect for experimental treatment in RCTs. The pooled ROR was 0.71 (95% CI: 0.63, 0.79; P = 0.002), suggesting that RCTs (or meta-analysis of RCTs) were more likely to report beneficial effect for the experimental treatment than PS-based studies. The result remained unchanged in sensitivity analysis and meta-regression.

CONCLUSION

In critical care literature, PS-based observational study is likely to report less beneficial effect of experimental treatment compared with RCTs (or meta-analysis of RCTs).

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.

Nutrition support in the intensive care patient

Nutrition intervention plays a significant role in changing patient clinical outcomes in the intensive care unit. Identifying patients at nutrition risk with a validated tool is essential. The decision to use enteral or parenteral nutrition is patient dependent and should include an assessment of the patient's gastrointestinal function. Protein is a critical component of the nutrition prescription, and prescribed levels may need to be higher than current guidelines recommend. Alternative lipids, such as olive oil and fish oil, are still being evaluated for their potential clinical impact. Avoiding nutrition therapy-associated complications, such as catheter infection and hyperglycemia, are important factors in being able to maximize the effectiveness of a nutritional intervention.

[Immunonutrition in intensive care medicine]

The review presents the concept of immunonutrition in enteral and parenteral nutrition of the critically ill. The present indications for supplementing immune enhancing and anti-inflammatory substances are summarized and discussed in accordance with the recent literature and guidelines.