Effects of intravenous fat emulsions on lung function in patients with acute respiratory distress syndrome or sepsis

Early versus late parenteral nutrition in term and late preterm infants: a randomised controlled trial

BACKGROUND

There is limited evidence regarding the optimal time to commence parenteral nutrition (PN) in term and late preterm infants.

DESIGN

Single-centre, non-blinded, exploratory randomised controlled trial.

SETTING

A level-3 neonatal unit in a stand-alone paediatric hospital.

PATIENTS

Infants born ≥34 weeks of gestation and ≤28 days, who needed PN. Eligible infants were randomised on day 1 or day 2 of admission.

INTERVENTIONS

Early (day 1 or day 2 of admission, N=30) or late (day 6 of admission, N=30) PN.

MAIN OUTCOME MEASURES

Plasma phenylalanine and F2-isoprostane levels on day 4 and day 8 of admission. Secondary outcomes were amino-acid and fatty-acid profiles on day 4 and day 8, and clinical outcomes.

RESULTS

The postnatal age at randomisation was similar between the groups (2.3 (SD 0.8) vs 2.3 (0.7) days, p=0.90). On day 4, phenylalanine levels in early-PN infants were higher than in late-PN (mean (SD) 62.9 (26.7) vs 45.5 (15.3) µmol/L; baseline-adjusted percentage difference 25.8% (95% CI 11.6% to 39.9%), p<0.001). There was no significant difference in phenylalanine levels between the two groups on day 8. There was no significant difference between the groups for F2-isoprostane levels on day 4 (early-PN mean (SD) 389 (176) vs late-PN 419 (291) pg/mL; baseline-adjusted percentage difference: -4.4% (95% CI -21.5% to 12.8%) p=0.62) and day 8 (mean (SD) 305 (125) vs 354 (113) pg/mL; adjusted mean percentage difference -16.1 (95% CI -34.1 to 1.9) p=0.09).Postnatal growth restriction for weight was less severe in the early-PN group (change in weight z-score from baseline to discharge: -0.6 (0.6) vs -1.0 (0.6); p=0.02). The incidence of hyperglycaemia was greater in the early-PN group (20/30 (66.7%) vs 11/30 (36.7%), p=0.02).

CONCLUSIONS

The timing of the commencement of PN did not seem to affect the degree of oxidative stress in critically ill term and late preterm infants. The effect of transiently high plasma phenylalanine with early PN on clinical outcomes requires further investigation.

TRIAL REGISTRATION NUMBER

ACTRN12620000324910.

Intravenous lipid emulsion for the treatment of poisonings in 313 dogs and 100 cats (2016-2020)

Introduction

The aim of this retrospective study was to analyze the effect and potential adverse effects of intravenous lipid emulsion (ILE) in poisoned dogs and cats over a 5 years period.

Methods

Medical records of 313 dogs and 100 cats receiving ILE between 2016-2020 were analyzed for suspected toxicant, clinical signs, ILE dosages and frequency, the effect and adverse effects of ILE, and patient outcome.

Results

Dogs and cats were poisoned with mostly unidentified toxicants (48%), rodenticides (8%), recreational drugs and nuts (7% each) and other toxicants. Clinical signs included neurologic deficits (63%), cardiovascular signs (29%), thermoregulation (21%) or gastrointestinal abnormalities (17%). Treatment with ILE was initiated within a median of 6.0 h (1.0-91.0 h) after poisoning. Dogs and cats received a total amount of median 8.0 mL/kg (1.5-66.6 mL/kg) and 15.8 mL/kg (1.8-69.4 mL/kg) ILE, respectively. A positive effect was observed in 74% of the patients, whereas clinical signs worsened in 4% of the patients after ILE administration. No subjective effect was detected in 22% of the patients. Suspected or possible adverse effects of ILE occurred in 6% of the patients, including neurological signs (temporarily reduced consciousness and ataxia), bradycardia, hyperthermia, vomiting, diarrhea, respiratory distress, worsening of the general behavior, facial swelling, and thrombophlebitis. The overall survival rate was 96%. One dog who potentially experienced adverse events was euthanized.

Conclusion

ILE treatment was successful in most patients but can be associated with adverse effects. Administration of ILE should be carefully selected on an individual basis after weighing the possible benefits against potential adverse effects.

Metabolic Support in Acute Respiratory Distress Syndrome: A Narrative Review

Nutritional support for acute respiratory distress syndrome (ARDS) patients shares metabolic notions common to other critically ill conditions. Nevertheless, it generates specific concern regarding the primary limitation of oxygen supply and the complications of carbon dioxide elimination, as well as the significant metabolic alterations due to the body's response to illness. In the present narrative review, after briefly summarizing the pathophysiology of critical illness stress response and patients' metabolic requirements, we focus on describing the characteristics of metabolic and artificial nutrition in patients with acute respiratory failure. In patients with ARDS, several aspects of metabolism assume special importance. The physiological effects of substrate metabolism are described for this setting, particularly regarding energy consumption, diet-induced thermogenesis, and the price of their clearance, transformation, and storage. Moreover, we review the possible direct effects of macronutrients on lung tissue viability during ARDS. Finally, we summarize the noteworthy characteristics of metabolic control in critically ill patients with ARDS and offer a suggestion as to the ideal methods of metabolic support for this problem.

Early versus late parenteral nutrition in term and late preterm infants: study protocol for a randomised controlled trial

BACKGROUND

Despite the wide use of parenteral nutrition (PN) in neonatal intensive care units (NICU), there is limited evidence regarding the optimal time to commence PN in term and late preterm infants. The recommendations from the recently published ESPGHAN/ESPEN/ESPR/CPEN and NICE guidelines are substantially different in this area, and surveys have reported variations in clinical practice. The aim of this randomised controlled trial (RCT) is to evaluate the benefits and risks of early versus late PN in term and late preterm infants.

METHODS/DESIGN

This study is a single-centre, non-blinded RCT in the NICU of Perth Children's Hospital, Western Australia.A total of 60 infants born ≥34 weeks of gestation who have a high likelihood of intolerance to enteral nutrition (EN) for at least 3-5 days will be randomised to early (day 1 or day 2 of admission) or late commencement (day 6 of admission) of PN after informed parental consent. In both groups, EN will be commenced as early as clinically feasible. Primary outcomes are plasma phenylalanine and plasma F₂-isoprostane levels on Day 4 and Day 8 of admission. Secondary outcomes are total and individual plasma amino acid profiles, plasma and red blood cell fatty acid profiles, in-hospital all-cause mortality, hospital-acquired infections, length of hospital/NICU stay, z scores and changes in z scores at discharge for weight, height and head circumference, time to full EN, duration of respiratory (mechanical, non-invasive) support, duration of inotropic support, the incidence of hyper and hypoglycaemia, incidence of metabolic acidosis, liver function, blood urea nitrogen, and C-reactive protein (CRP).

DISCUSSION

This RCT will examine the effects of early versus late PN in term and late preterm infants by comparing key biochemical and clinical outcomes and has the potential to identify underlying pathways for beneficial or harmful effects related to the timing of commencement of PN in such infants.

TRIAL REGISTRATION

ANZCTR; ACTRN12620000324910 (3rd March 2020).

Fatal accidental lipid overdose with intravenous composite lipid emulsion in a premature newborn: a case report

BACKGROUND

Tenfold or more overdose of a drug or preparation is a dreadful adverse event in neonatology, often due to an error in programming the infusion pump flow rate. Lipid overdose is exceptional in this context and has never been reported during the administration of a composite intravenous lipid emulsion (ILE).

CASE PRESENTATION

Twenty-four hours after birth, a 30 weeks' gestation infant with a birthweight of 930 g inadvertently received 28 ml of a composite ILE over 4 h. The ILE contained 50% medium-chain triglycerides and 50% soybean oil, corresponding to 6 g/kg of lipids (25 mg/kg/min). The patient developed acute respiratory distress with echocardiographic markers of pulmonary hypertension and was treated with inhaled nitric oxide and high-frequency oscillatory ventilation. Serum triglyceride level peaked at 51.4 g/L, 17 h after the lipid overload. Triple-volume exchange transfusion was performed twice, decreasing the triglyceride concentration to < 10 g/L. The infant's condition remained critical, with persistent bleeding and shock despite supportive treatment and peritoneal dialysis. Death occurred 69 h after the overdose in a context of refractory lactic acidosis.

CONCLUSIONS

Massive ILE overdose is life-threatening in the early neonatal period, particularly in premature and hypotrophic infants. This case highlights the vigilance required when ILEs are administered separately from other parenteral intakes. Exchange transfusion should be considered at the first signs of clinical or biological worsening to avoid progression to multiple organ failure.

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.

Parenteral Nutrition and Cardiotoxicity

Parenteral nutrition (PN) is a life-saving nutritional therapy for those situations when patients are unable to receive enteral nutrition. However, despite a multitude of benefits offered by PN, it is associated with a variety of side effects, most notably parenteral nutrition-associated liver disease (PNALD). Adverse effects of PN on other organ systems, such as brain and cardiovascular system, have been poorly studied. There have been several case reports, studies, and a recent animal study highlighting cardiotoxic effects of PN; however, much remains unclear about the underlying mechanisms causing cardiac damage. In this review, we propose a series of potential mechanisms behind PN-associated heart injury, and we provide an overview of therapeutic strategies and recent scientific advances.

Lipid Use in Hospitalized Adults Requiring Parenteral Nutrition

In hospitalized patients, lipid emulsions are an integral part of balanced parenteral nutrition. Traditionally, a single lipid source, soybean oil, has been given to patients and was usually regarded as just a source of energy and to prevent essential fatty-acid deficiency. However, mixtures of different lipid emulsions have now become widely available, including mixtures of soybean oil, medium-chain triglycerides, olive oil, and fish oil. Fish oil is high in the ω-3 polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). There is a growing body of evidence that these ω-3 fatty acids can exert beneficial immunomodulatory, anti-inflammatory, and inflammation-resolution effects across a wide range of patient groups including surgical, cancer, and critically ill patients. At least in part, these effects are realized via potent specialized pro-resolution mediators (SPMs). Moreover, parenteral nutrition including ω-3 fatty acids can result in additional clinical benefits over the use of standard lipid emulsions, such as reductions in infection rates and length of hospital and intensive care unit stay. Clinical and experimental evidence is reviewed regarding lipid emulsion use in a variety of hospitalized patient groups, including surgical, critically ill, sepsis, trauma, and acute pancreatitis patients. Practical aspects of lipid emulsion use in critically ill patients are also considered, such as how to determine and fulfill energy expenditure, how and when to consider parenteral nutrition, duration of infusion, and safety monitoring.

Guidelines for parenteral and enteral nutrition in geriatric patients in China

Based on the expert consensus on parenteral and enteral nutrition support for geriatric patients in China in 2013, domestic multidisciplinary experts were gathered to summarize the new evidence in the field of elderly nutritional support at home and abroad. The 2013 consensus was comprehensively updated and upgraded to a guideline by referring to the World Health Organization (WHO) guidelines for the Grading of Recommendations Assessment, Development, and Evaluation system for grading evidence. These guidelines were divided into two parts: general conditions and common diseases. After discussion by all members of the academic group and consultation with relevant experts, 60 recommendations were ultimately established as standardized nutritional support in the field of geriatrics in China.

Early versus late parenteral nutrition for critically ill term and late preterm infants

BACKGROUND

Recently conducted randomised controlled trials (RCTs) suggest that late commencement of parenteral nutrition (PN) may have clinical benefits in critically ill adults and children. However, there is currently limited evidence regarding the optimal timing of commencement of PN in critically ill term and late preterm infants.

OBJECTIVES

To evaluate the benefits and safety of early versus late PN in critically ill term and late preterm infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (5 April 2019), MEDLINE Ovid (1966 to 5 April 2019), Embase Ovid (1980 to 5 April 2019), EMCare (1995 to 5 April 2019) and MEDLINE via PubMed (1966 to 5 April 2019). We searched for ongoing or recently completed clinical trials, and also searched the grey literature and reference lists of relevant publications.

SELECTION CRITERIA

We included RCTs comparing early versus late initiation of PN in term and late preterm infants. We defined early PN as commencing within 72 hours of admission, and late PN as commencing after 72 hours of admission. Infants born at 37 weeks' gestation or more were defined as term, and infants born between 34 and 36⁺⁶ weeks' gestation were defined as late preterm.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the trials, extracted the data and assessed the risk of bias. Treatment effects were expressed using risk ratio (RR) and risk difference (RD) for dichotomous outcomes and mean difference (MD) for continuous data. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Two RCTs were eligible for inclusion. Data were only available from a subgroup (including 209 term infants) from one RCT in children (aged from birth to 17 years) conducted in Belgium, the Netherlands and Canada. In that RCT, children with medium to high risk of malnutrition were included if a stay of 24 hours or more in the paediatric intensive care unit (PICU) was expected. Early PN and late PN were defined as initiation of PN within 24 hours and after day 7 of admission to PICU, respectively. The risk of bias for the study was considered to be low for five domains and high for two domains. The subgroup of term infants that received late PN had significantly lower risk of in-hospital all-cause mortality (RR 0.35, 95% confidence interval (CI) 0.14 to 0.87; RD -0.10, 95% CI -0.18 to -0.02; number needed to treat for an additional beneficial outcome (NNTB) = 10; 1 trial, 209 participants) and neonatal mortality (death from any cause in the first 28 days since birth) (RR 0.29, 95% CI 0.10 to 0.88; RD -0.09, 95% CI -0.16 to -0.01; NNTB = 11; 1 trial, 209 participants). There were no significant differences in rates of healthcare-associated blood stream infections, growth parameters and duration of hospital stay between the two groups. Neurodevelopmental outcomes were not reported. The quality of evidence was considered to be low for all outcomes, due to imprecision (owing to the small sample size and wide confidence intervals) and high risk of bias in the included studies.

AUTHORS' CONCLUSIONS

Whilst late commencement of PN in term and late preterm infants may have some benefits, the quality of the evidence was low and hence our confidence in the results is limited. Adequately powered RCTs, which evaluate short-term as well as long-term neurodevelopmental outcomes, are needed.

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.

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.

The Effects of Immediate Enteral Feeding with a Formula Containing High Levels of ω-3 Fatty Acids in Patients After Surgery for Esophageal Cancer

BACKGROUND

We investigated whether supplementation of enteral nutrition (EN) with omega-3 polyunsaturated acids (PUFAs) affected platelet aggregation, coagulation activity, and inflammatory response in the early stages after esophageal cancer surgery.

METHODS

Twenty-eight patients with esophageal cancer who underwent the same surgical procedure were selected for this study. All patients received EN, which was started immediately after the operation and was increased to a maximum volume of 1500 ml/day by the third postoperative day (POD). Eleven patients received a conventional EN formula (Ensure Liquid), while the remaining 17 patients received a different formula rich in omega-3 PUFAs (Racol [RAC]). Several markers of coagulation and fibrinolysis were determined in POD 2, while the concentrations of interleukin (IL)-6, IL-8, 6-keto-PGF1alpha and thromboxane B2 were determined on PODs 1, 3, and 5.

RESULTS

A total of 27 patients completed the study, 11 in the Ensure Liquid group and 16 in the RAC group. Administration of RAC significantly inhibited the postoperative decrease in platelet count. The level of D-dimer was attenuated significantly in the RAC group. Plasma IL-8 levels were decreased significantly in the RAC group on PODs 1 and 3. The anti-inflammatory effects of omega-3 PUFAs were confirmed by the clinical findings of lower body temperature. The plasma concentration of 6-keto-PFG1alpha also tended to decrease in the RAC group with a significant difference on POD 5.

CONCLUSIONS

Early EN with a large amount of omega-3 PUFAs in reduced platelet aggregation, coagulation activity, and cytokine production. All these effects would be expected to be beneficial in patients following esophageal cancer surgery. The clinical significance of the changes in eicosanoid production remains to be established.

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.

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.

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

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

Use of early inhaled nitric oxide therapy in fat embolism syndrome to prevent right heart failure

Fat embolism syndrome (FES) is a life-threatening condition in which multiorgan dysfunction manifests 48–72 hours after long bone or pelvis fractures. Right ventricular (RV) failure, especially in the setting of pulmonary hypertension, is a frequent feature of FES. We report our experience treating 2 young, previously healthy trauma patients who developed severe hypoxemia in the setting of FES. Neither patient had evidence of RV dysfunction on echocardiogram. The patients were treated with inhaled nitric oxide (NO), and their oxygenation significantly improved over the subsequent few days. Neither patient developed any cardiovascular compromise. Patients with FES that have severe hypoxemia and evidence of adult respiratory distress syndrome (ARDS) are likely at risk for developing RV failure. We recommend that these patients with FES and severe refractory hypoxemia should be treated with inhaled NO therapy prior to the onset of RV dysfunction.

Lipid resuscitation in pediatric patients - need for caution?

A 3-year-old child was successfully resuscitated following bupivacaine cardiotoxicity with 20% intravenous lipid emulsion (ILE). Large volume of ILE was used targeting clinically adequate perfusion. Subsequently, there were features of ventilation/perfusion (V/P) mismatch.

[Calories, proteins - what does the intensive care patient need?]

It is increasingly recognized that the nutrition of critically ill patients is a highly complex activity with many unanswered questions. Much research has been performed showing that early enteral nutrition helps to avoid complications. In addition, it has already been shown that the calorie goal as the sole diet goal rather plays a minor role, if one pays attention to sufficient supply of proteins. The diet of the different patient groups with their very individual physiological conditions and their very different diseases are another difficile question in nutritional therapy. The question about the best access path currently appears clearly to be the way of enteral nutrition. Although there seems to be no clear advantage to the gastric or jejunal route, the gastric tube is apparently used more often in clinical practice due to the ease of placement. Reflux control is also currently controversially discussed. To assess the intestinal transport capacity, control of reflux is inevitable, but the amount of reflux that should be considered as cut-off criteria is still unclear. The field of immunonutrition or the substitution of selenium, glutamine, and other substances requires further research. The goal of this article is to provide the reader with a review of the current literature concerning nutritional needs of intensive care patients.

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 in intensive care medicine: Part 2: special nutritional problems]

Therapy of intensive care patients is often complicated by co-morbidities or complex systemic disorders such as sepsis. The necessity to generate an individualized nutritional regime has gained in importance in recent years as this essential part of supportive care has a direct impact on the prognosis of the patient. In the present article a special focus is put on particular questions of nutritional aspects of intensive care patients. The current guidelines and study data on disorders relevant in intensive care medicine, such as acute or chronic renal and liver failure, acute respiratory distress syndrome and sepsis are presented and discussed. Another focus is the establishment of an adequate nutritional regime for patients after operations or suffering from multiple trauma.

[Nutrition and acute respiratory failure]

Acute respiratory distress syndrome (ARDS) is characterized by the formation of a protein-rich alveolar edema caused by increased permeability of the alveolocapillary membrane. The key clinical feature is refractory arterial hypoxemia, which in severe cases necessitates the application of extracorporeal membrane oxygenation. Besides lung-protective ventilation as a confirmed therapeutic option, supportive therapy is an integral part of ARDS management. In this context, modern and individualized nutritional regimens are of special importance; however, their prognostic impact, especially of immunonutrition, for ARDS patients is controversial. In this review, basic features of nutrition in intensive care medicine and ARDS-specific aspects (e.g., immunonutrition) are presented and discussed.

Caveolar uptake and endothelial-protective effects of nanostructured lipid carriers in acid aspiration murine acute lung injury

PURPOSE

Nanostructured lipid carriers (NLC), nanosized phospholipids/triglyceride particles developed for drug delivery, are considered biologically inactive. We assessed the efficacy of unloaded NLC as experimental treatment for acute lung injury (ALI).

METHODS

To induce ALI, C57Black/6 male mice received intratracheal injections of HCl or saline; A single dose of 16 mg/Kg NLC or saline was injected intravenously concomitantly with HCl challenge. NLC uptake mechanisms and effects on endothelial permeability and signaling were studied in cultured endothelial cells and neutrophils.

RESULTS

NLC pre-treatment attenuated pulmonary microvascular protein leak, airspace inflammatory cells, thrombin proteolytic activity and histologic lung injury score 24 h post insult. Using fluorescence measurements and flow cytometry in mouse lung microvascular endothelial cell culture homogenates, we determined that NLC rendered fluorescent by curcumin labeling are taken up by endothelial cells from mice expressing caveolin-1, the coat protein of caveolar endocytic vesicles, but not from caveolin-1 gene-disrupted mice, which lack caveolae. In contrast, conventional emulsions (CE), consisting of larger particles, were not incorporated. In addition, NLC pre-treatment of cultured human lung microvascular endothelial cells abrogated thrombin-induced activation of p44/42, albumin permeability response, actin cytoskeletal remodeling and interleukin-6 production. Finally, NLC but not CE abrogated lipopolysaccharide-triggered interleukin-8 release.

CONCLUSIONS

NLC are engulfed by endothelial caveolae and possess endothelial-protective effects. These novel properties may be of potential utility in ALI.

Iloprost improves endothelial barrier function in lipopolysaccharide-induced lung injury

The protective effects of prostacyclin and its stable analogue iloprost are mediated by elevation of intracellular cyclic AMP (cAMP) leading to enhancement of the peripheral actin cytoskeleton and cell-cell adhesive structures. This study tested the hypothesis that iloprost may exhibit protective effects against lung injury and endothelial barrier dysfunction induced by bacterial wall lipopolysaccharide (LPS). Endothelial barrier dysfunction was assessed by measurements of transendothelial permeability, morphologically and by analysis of LPS-activated inflammatory signalling. In vivo, C57BL/6J mice were challenged with LPS with or without iloprost or 8-bromoadenosine-3',5'-cyclic monophosphate (Br-cAMP) treatment. Lung injury was monitored by measurements of bronchoalveolar lavage protein content, cell count and Evans blue extravasation. Iloprost and Br-cAMP attenuated the disruption of the endothelial monolayer, and suppressed the activation of p38 mitogen-activated protein kinase (MAPK), the nuclear factor (NF)-κB pathway, Rho signalling, intercellular adhesion molecular (ICAM)-1 expression and neutrophil migration after LPS challenge. In vivo, iloprost was effective against LPS-induced protein and neutrophil accumulation in bronchoalveolar lavage fluid, and reduced myeloperoxidase activation, ICAM-1 expression and Evans blue extravasation in the lungs. Inhibition of Rac activity abolished the barrier-protective and anti-inflammatory effects of iloprost and Br-cAMP. Iloprost-induced elevation of intracellular cAMP triggers Rac signalling, which attenuates LPS-induced NF-κB and p38 MAPK inflammatory pathways and the Rho-dependent mechanism of endothelial permeability.

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.

Fish oil-containing lipid emulsions in patients with sepsis

Lipid emulsions based on soybean oil have been an integral part of parenteral nutrition supplying n-6 fatty acids, with possible negative effects in critically ill patients. Newer lipid emulsions supply less n-6 fatty acids. In addition, fish oil-based lipids may be included in the lipid component of parenteral nutrition. While clinical benefits of lipid emulsions with a reduced fraction in n-6 lipids and the addition of fish oil have been described in postoperative patients, data are less clear in critically ill or septic patients. Recent data suggest that beneficial effects may be achieved when used early but clearly more data are needed to come to a definitive conclusion. The present commentary will highlight current data in critically ill and septic patients and the use of fish oil as a part of parenteral nutrition.

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.

Effect of short-term intralipid infusion on the immune response during low-dose endotoxemia in humans

Novel anti-inflammatory effects of insulin have recently been described, and insulin therapy to maintain euglycemia suppresses the plasma levels of free fatty acids (FFA) and increases the survival of critically ill patients. We aimed to explore the effect of short-term high levels of plasma FFA on the inflammatory response to a low dose of endotoxin. Fourteen healthy male volunteers underwent the following two trials in a randomized crossover design: 1) continuous infusion of 20% Intralipid [0.7 ml.kg(-1).h(-1) (1.54 g/kg)] for 11 h, and 2) infusion of isotonic saline for 11 h (control). In each trial, heparin was given to activate lipoprotein lipase, and an intravenous bolus of endotoxin (0.1 ng/kg) was given after 6 h of Intralipid/saline infusion. Blood samples and muscle and fat biopsies were obtained before the Intralipid/saline infusion and before as well as after infusion of an endotoxin bolus. Plasma levels of FFA, triglycerides, and glycerol were markedly increased during the Intralipid infusion. Endotoxin exposure induced an increase in plasma levels of TNF-alpha, IL-6, and neutrophils and further stimulated gene expression of TNF-alpha and IL-6 in both skeletal muscle and adipose tissue. The systemic inflammatory response to endotoxin was significantly pronounced during Intralipid infusion. Short-term hyperlipidemia enhances the inflammatory response to endotoxin, and skeletal muscle and adipose tissue are capable of producing essential inflammatory mediators after endotoxin stimulation.

Congenital NOS2 deficiency prevents impairment of hypoxic pulmonary vasoconstriction in murine ventilator-induced lung injury

Hypoxic pulmonary vasoconstriction (HPV) preserves systemic arterial oxygenation during lung injury by diverting blood flow away from poorly ventilated lung regions. Ventilator-induced lung injury (VILI) is characterized by pulmonary inflammation, lung edema, and impaired HPV leading to systemic hypoxemia. Studying mice congenitally deficient in inducible nitric oxide synthase (NOS2) and wild-type mice treated with a selective NOS2 inhibitor, L-N(6)-(1-iminoethyl)lysine (L-NIL), we investigated the contribution of NOS2 to the impairment of HPV in anesthetized mice subjected to 6 h of either high tidal volume (HV(T)) or low tidal volume (LV(T)) ventilation. HPV was estimated by measuring the changes of left lung pulmonary vascular resistance (LPVR) in response to left mainstem bronchus occlusion (LMBO). LMBO increased the LPVR similarly in wild-type, NOS2(-/-), and wild-type mice treated with L-NIL 30 min before commencing 6 h of LV(T) ventilation (96% +/- 30%, 103% +/- 33%, and 80% +/- 16%, respectively, means +/- SD). HPV was impaired in wild-type mice subjected to 6 h of HV(T) ventilation (23% +/- 16%). In contrast, HPV was preserved after 6 h of HV(T) ventilation in NOS2(-/-) and wild-type mice treated with L-NIL either 30 min before or 6 h after commencing HV(T) ventilation (66% +/- 22%, 82% +/- 29%, and 85% +/- 16%, respectively). After 6 h of HV(T) ventilation and LMBO, systemic arterial oxygen tension was higher in NOS2(-/-) than in wild-type mice (192 +/- 11 vs. 171 +/- 17 mmHg; P < 0.05). We conclude that either congenital NOS2 deficiency or selective inhibition of NOS2 protects mice from the impairment of HPV occurring after 6 h of HV(T) ventilation.

Immunomodulation by n-3- versus n-6-rich lipid emulsions in murine acute lung injury--role of platelet-activating factor receptor

OBJECTIVE

Cytokines, platelet-activating factor (PAF), and eicosanoids control local and systemic inflammation. Conventional soybean oil-based lipid emulsions used for parenteral nutrition may aggravate the leukocyte inflammatory response or adhesion to the vessel wall. Fish oil-based lipid emulsions, in contrast, may exert an anti-inflammatory effect.

DESIGN

We investigated the impact of lipid emulsions on leukocyte invasion, protein leakage, and cytokines in two murine models of acute inflammation.

SETTING

Research laboratory of a university hospital.

SUBJECTS

Wild-type mice and PAF-receptor knockout mice.

INTERVENTIONS

Mice received an infusion of normal saline, fish oil- or soybean oil-based lipid emulsions before lipopolysaccharide challenge.

MEASUREMENTS AND MAIN RESULTS

Preinfusion with soybean oil resulted in increased leukocyte invasion, myeloperoxidase activity, and protein leakage and exaggerated release of tumor necrosis factor (TNF)-alpha as well as macrophage inflammatory protein (MIP)-2 into the alveolar space after intratracheal lipopolysaccharide challenge. In contrast, preinfusion with fish oil reduced leukocyte invasion, myeloperoxidase activity, protein leakage, and TNF-alpha as well as MIP-2 generation. Corresponding profiles were found in plasma following intraperitoneal lipopolysaccharide application: Soybean oil increased but fish oil decreased the TNF-alpha and MIP-2 formation. When PAF-receptor-deficient mice were challenged with lipopolysaccharide, leukocyte invasion, lung tissue myeloperoxidase, cytokine generation, and alveolar protein leakage corresponded to those observed in wild-type animals. Fish oil and soybean oil lost their diverging effects on leukocyte transmigration, myeloperoxidase activity, leakage response, and cytokine generation in these knockout mice. Similarly, the differential impact of both lipid emulsions on these lipopolysaccharide-provoked changes was suppressed after pretreating animals with a PAF-receptor antagonist.

CONCLUSIONS

Fish oil- vs. soybean oil-based lipid infusions exert anti- vs. proinflammatory effects in murine models of acute inflammation. The PAF/PAF-receptor-linked signaling appears to be a prerequisite for this differential profile.

Mechanism of hypoxemia in acute lung injury evaluated by multidetector-row CT

RATIONALE AND OBJECTIVES

Hypoxic pulmonary vasoconstriction (HPV) is a homeostatic mechanism causing pulmonary arterial constriction in response to local hypoxia, redistributing blood flow to lung regions with better oxygenation and ventilation. We present the use of computed tomographic (CT) volume and perfusion imaging to show differences in the mechanisms of hypoxemia from alterations in blood flow distribution within different animal models of acute lung injury (ALI).

MATERIALS AND METHODS

Three anesthetized, instrumented, and ventilated sheep were studied, two with induced ALI and one with native pneumonia. One subject was injured by using intravenous infusion of lipopolysaccharide (LPS), and the other, by repetitive saline lavage. Subjects were imaged using multidetector-row CT (MDCT) before and after injury. Lung volume scans were gated to the respiratory cycle. Contrast injection perfusion images were electrocardiogram gated. Computer-based image analysis quantified regional blood flow and total lung, air, and tissue volumes.

RESULTS

Total lung air fraction was decreased in both ALI models. In lavage injury, there was a decrease in perfusion to dependent poorly aerated regions, with perfusion shifting to nondependent regions. Conversely, LPS injury greatly increased perfusion to dependent poorly aerated regions. In the subject with pneumonia, decreasing fraction of inspired oxygen redistributed blood flow into the injured regions.

CONCLUSIONS

MDCT techniques can be used to investigate regional lung perfusion and lung volume distributions to explain physiological mechanisms in ALI. Our findings suggest that after lavage injury, blood flow is redistributed, consistent with preserved HPV and resulting in better oxygenation despite greater lung volume loss compared with LPS injury. In native pneumonia, HPV inactivation can be localized to the injured regions.

Benefit of an enteral diet enriched with eicosapentaenoic acid and gamma-linolenic acid in ventilated patients with acute lung injury*

OBJECTIVE

To explore the effects of an enteral diet enriched with eicosapentaenoic acid (EPA), gamma-linolenic acid (GLA), and antioxidants on the respiratory profile and outcome of patients with acute lung injury.

DESIGN

Single-center, prospective, randomized, controlled, unblinded study.

SETTING

General intensive care department of a tertiary-care, university-affiliated hospital.

PATIENTS

A total of 100 patients with acute lung injury, diagnosed according to the American-European Consensus Conference on ARDS.

INTERVENTIONS

Patients were randomized to receive the standard isonitrogenous, isocaloric enteral diet or the standard diet supplemented with EPA and GLA for 14 days.

MEASUREMENTS AND MAIN RESULTS

Patient demographics, Acute Physiology and Chronic Health Evaluation II score, and type of admission were noted at admission. Compared with baseline oxygenation (EPA + GLA group vs. control group), by days 4 and 7, patients receiving the EPA + GLA diet showed significant improvement in oxygenation (PaO(2)/FIO(2), 317.3 +/- 99.5 vs. 214.3 +/- 56.4 and 296.5 +/- 165.3 vs. 236.3 +/- 79.8, respectively; p < .05). Compliance was significantly higher in the EPA + GLA group observed at day 7 (55.1 +/- 46.5 vs. 35.2 +/- 20.0 mL/mbar, p < .05). No significant difference was found in nutritional variables. Resting energy expenditure was significantly higher in patients in the EPA + GLA group, but their body mass index was also higher (p < .05). A significant difference was found in length of ventilation (p < .04) in favor of the EPA + GLA group. There was no between-group difference in survival.

CONCLUSIONS

In patients with acute lung injury, a diet enriched with EPA + GLA may be beneficial for gas exchange, respiratory dynamics, and requirements for mechanical ventilation.

Nutrition support for patients in the intensive care unit

Enteral nutrition (EN) is the mainstay of nutrition delivery within intensive care seeking to capitalise on its benefits for the gastrointestinal tract and associated immune system, but this has brought new challenges in delivery to the sick. The hoped for benefit has led to the mistaken belief by some that parenteral nutrition (PN) is no longer required. However, a greater appreciation of the risks of EN delivery in the sick patient combined with improvements in PN formulation and use help explain why PN is not as risky as some have believed. Real outcome benefits have been described with the new glutamine containing PN formulations. PN remains important in the presence of gastrointestinal feed intolerance or failure.

Propofol attenuates oxidant-induced acute lung injury in an isolated perfused rabbit-lung model

PURPOSE

Reactive oxygen species have been strongly implicated in the pathogenesis of acute lung injury (ALI). Some animal studies suggest that free radical scavengers inhibit the onset of oxidant-induced ALI. Propofol (2,6-diisopropylphenol) is chemically similar to phenol-based free radical scavengers such as the endogenous antioxidant vitamin E. Both in vivo and in vitro studies have suggested that propofol has antioxidant potential. We hypothesized that propofol may attenuate ALI by acting as a free-radical scavenger.

METHODS

We investigated the effects of propofol on oxidant-induced ALI induced by purine and xanthine oxidase (XO), in isolated perfused rabbit lung, in two series of experiments. In series 1, we examined the relationship between the severity of ALI and the presence of hydrogen peroxide (H2O2). In series 2, we evaluated the effects of propofol on attenuating ALI and the dose dependence of these effects. The lungs were perfused for 90 min, and we evaluated the effects on the severity of ALI by monitoring the pulmonary capillary filtration coefficient (Kfc), pulmonary arterial pressure (Ppa), and the pulmonary capillary hydrostatic pressure (Ppc).

RESULTS

In series 1, treatment with catalase (an H2O2 scavenger) prior to the addition of purine and XO resulted in complete prevention of ALI, suggesting that H2O2 may be involved closely in the pathogenesis of ALI. In series 2, pretreatment with propofol at concentrations in excess of 0.5 mM significantly inhibited the increases in the Kfc values, and that in excess of 0.75 mM significantly inhibited the increase in the Ppa values.

CONCLUSION

Propofol attenuates oxidant-induced ALI in an isolated perfused rabbit lung model, probably due to its antioxidant action.

Perioperative administration of parenteral fish oil supplements in a routine clinical setting improves patient outcome after major abdominal surgery

BACKGROUND & AIMS

It is hypothesized that provision of pre- and/or postoperative omega-3 fatty acids to surgical patients in clinical routine improves clinical outcome.

METHODS

Retrospective evaluation of a 2-year-longitudinal data base of ICU patients (n=249) elected for major abdominal surgery. Group I (n=110): postoperative standard parenteral nutrition (1.2 g amino acids, 0.3 g glutamine dipeptide, 0.6 g lipids, 4 g/kg glucose; energy ratio glucose to lipid 2:1); group II (n=86): part of postoperative lipid emulsion replaced by fish oil; group III (n=53): in addition 2-3 days preoperative fish oil supplementation (max. 100 ml/d).

RESULTS

A decrease in mortality was observed in group III compared to group I (P=0.02). The number of patients requiring mechanical ventilation was lower with perioperative fish oil (n=34 in groups I and II. 10 in III, P<0.05). The number of days in ICU was not different (group I: 7.6 days, group II: 7.0, group III: 7.3), the length of hospital stay was shorter in group I (group I: 29.2 days, group II: 24.9, group III: 22.2, P<0.05 vs I).

CONCLUSIONS

In a retrospective evaluation, perioperative provision of parenteral fish oil (ca. 10 g/day) beneficially influences patient outcome probably by modulating the immune response.

The Impact of Intravenous Fat Emulsion Administration in Acute Lung Injury

The aim of this study was to evaluate the effect of parenteral nutrition containing medium- and long-chain triglycerides on the function of the respiratory system and to investigate mechanisms involved in this process. We studied 13 patients with acute respiratory distress syndrome (ARDS), 8 receiving lipid and 5 placebo, and 6 without ARDS, receiving lipid. Bronchoalveolar lavage (BAL) was performed before and 1 hour after administration of lipid or placebo. In patients with ARDS, lipid administration resulted in deterioration of oxygenation (Pa(O(2))/FI(O(2)): from 129 +/- 37 to 95 +/- 42), compliance of respiratory system (from 39.2 +/- 12 to 33.1 +/- 9.2 ml/cm H(2)O), and pulmonary vascular resistance (from 258 +/- 47 to 321 +/- 58 dyne x s x cm(-5)). In the BAL fluid of the same group, an increase in total protein and phospholipid concentrations, phospholipase activities, platelet-activating factor and neutrophils, as well as alterations in BAL lipid profile were observed. No significant changes were observed in the control or in the ARDS-Placebo groups. In conclusion, this study indicates that administration of medium- and long-chain triglycerides in patients with ARDS causes alterations in lung function and hemodynamics. Inflammatory cells, possibly activated by lipids, release phospholipase A(2) and platelet-activating factor, enhancing edema formation, inflammation, and surfactant alterations.