The Effect of Intravenous Lipids on Lung Function in Acute Respiratory Distress Syndrome (ARDS)

The purpose of this study is to evaluate the effects of nutritional supplementation with omega-9 "olive-oil" and omega-6 "soybean oil" based lipid emulsions in the Acute Respiratory Distress Syndrome (ARDS). The investigators hypothesize that these specific lipids in combination will immunomodulate the inflammatory reaction that occurs in the lungs of ARDS subjects. This concept is known as "Pharmaconutrition." These lipids will be given intravenously so as to assure administration and only as a supplement to enteral nutrition which all subjects will also receive. The omega-9 will be compared to the omega-6 formulation which is the only FDA approved formulation of use in the United States since its development in 1961 by Fresenius-Kabi, Bad Homburg, Germany. The investigators plan to perform a bronchoscopy with lavage within 24 hours of enrollment, begin the lipid administration and continue it for 96 hours after which time the investigators will repeat bronchoscopy with lavage to assess changes. The lipid administration will cease following the second bronchoscopy. The fluid obtained from lavage combined with serum samples obtained at the time of bronchoscopy will be analyzed for inflammatory mediators and cell counts. Clinical data tracing will include but not be limited to: ventilator days, nutritional status, ICU time, oxygenation and lung compliance, and 30-day mortality.

We will use standard clinical criteria including but not limited to: fever, pyuria, new inflitrate on chest x-ray, positive blood cultures, abscess detected on imaging, leukocytosis, and positive skin or soft-tissue cultures to identify presence of new bacterial infections occurring after enrollment.

Inclusion Criteria: diagnosed with predisposing condition causing ARDS are mechanically ventilated through an endotracheal tube have enteral feeding access have central venous access have a PaO2:FiO2 ratio of less than 200 have bilateral pulmonary infiltrates on chest x-ray Exclusion Criteria: sedation requiring the use of diprivan (after enrollment) a clinical diagnosis of left ventricular failure lung cancer hematologic malignancy severe dyslipidemia condition precluding bronchoscopy including inability to maintain oxygen saturations greater than 90% per pulse oximetry despite conventional mechanical ventilation severe immunosuppression use of NSAIDS within previous 24 hours HIV positive pregnancy hypersensitivity to egg or soybean oil active myocardial infarction acute pancreatitis if complicated by hypertriglyceridemia severe sepsis with 2 or more organ failures