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

Abstract

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.

Providing optimal nutritional support on the intensive care unit: key challenges and practical solutions

“…As n -3 fatty acids compete with n -6 fatty acids in the synthetic pathway for pro-inflammatory eicosanoids, providing the correct ratio of fatty acid types may also be important. Mizock ( 47 ) suggested an optimum ratio of 1:2 n -6 to n -3 whereas other authors have suggested 1:3 ( 46 ) . While clearly some n -6 fatty acids are essential, they are pro-inflammatory and another way of possibly reducing the amount in enteral feeds would be to substitute some of the long-chain TAG for medium-chain TAG.…”

The role of oral supplementation with immunonutrients in the inflammatory response in patients with COVID-19

“…EPA and DHA anti-inflammatory mechanisms include: 1) removal of arachidonic acid from the phospholipid nucleus of inflammatory cell membranes, reducing the production of pro-inflammatory substance; 2) inhibition of synthesis of pro-inflammatory eicosanoids by competition with arachidonic acid in cyclooxygenase and lipoxygenase enzymes; 3) reduction of platelet and leukocyte adhesion in the endothelium; 4) inhibition of inflammatory gene expression; 5) reduction of oxidative lesions by stimulation of glutathione production; 6) improvement of anti-inflammatory resolvin synthesis; 7) a protective lung effect mediated by the reduction of the release of inflammatory mediators derived from the intestine in mesenteric lymphatic vessels and the thoracic duct (Glatzle et al, 2007;Mizock & DeMichele, 2004;Serhan, Arita, Hong, & Gotlinger, 2004).…”

Specialized Enteral Formulas in Acute and Chronic Pulmonary Disease

“…Several of these metabolites, thromboxane A 2 , leukotrienes, and prostaglandin E 2 , have been implicated in the development of acute lung injury. 27,33,34 A specialized enteral formula is available to potentially modulate this inflammatory cascade. The enteral formula offers a modified lipid component containing borage and fish oils, sources of eicosapentaenoic acid (EPA) and γ-linolenic (GLA) acid.…”

“…Vasoconstriction, platelet aggregation, and neutrophil accumulation are reduced when the eicosanoid balance favors anti-inflammatory rather than proinflammatory mediators. 33,36 The specialized enteral formula provides a greater amount of total lipid than do other formulas designed for metabolic stress. Approximately 55% of total calories are provided as lipid compared with a range of 30% to 39% for other metabolic enteral formulas.…”