Early Versus Delayed Enteral Feeding to Treat People With Acute Lung Injury or Acute Respiratory Distress Syndrome (The EDEN Study)

Overview

Acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are medical conditions that occur when there is severe inflammation and increased fluids in both lungs, making it difficult for the lungs to function properly. Hospital treatment for a person with ALI/ARDS often includes the use of a breathing machine, or ventilator, until the person is able to breathe without assistance. Initiating proper nutrition through a feeding tube early in a person's hospital stay may help to improve recovery, but the optimal timing, composition, and amount of feeding treatments remain unknown. This study will evaluate whether early or delayed full-calorie feeding through a feeding tube is more effective in reducing recovery time and increasing survival rates in people with ALI/ARDS.

ALI/ARDS involves extensive inflammation in the lungs that can lead to rapid respiratory failure. These conditions are most commonly caused by pneumonia, generalized infection, or severe trauma to the lungs, but can also be less commonly caused by smoke or salt water inhalation, drug overdose, or shock. For some people, ALI/ARDS resolves without treatment, but many severe cases result in hospitalization in the intensive care unit (ICU), where 30% to 40% of cases end in mortality. Current treatments for ALI/ARDS include assisted breathing with a ventilator, supportive care, and management of the underlying causes. Enteral feeding, in which patients receive nutrition through a feeding tube, plays an important role in treatment, too. Some recent studies have shown that enteral feeding initiated soon after a patient begins assisted breathing is associated with a shorter hospital stay and a better chance of survival than delayed enteral feeding. However, other studies have shown the opposite, and studies on optimal feeding volume and composition have shown conflicting results. This study will evaluate the effects of early versus delayed full-calorie enteral feeding on mortality, ventilator-free days, ICU-free days, and organ failure in people with ALI/ARDS. Upon admission to the ICU, a dietary evaluation will be done on each participant to determine goal, or full-calorie, feeding rates, which will be based on body weight and daily energy consumption. Participants will also undergo baseline assessments and procedures, which will include vital sign measurements, blood draws, a frontal chest radiograph, ventilator settings, and placement of a feeding tube. Participants will be randomly assigned to receive initial enteral feedings that are either minimal (trophic) or full-calorie. All participants will begin enteral feeding within 6 hours of treatment assignment. Participants assigned to initial minimal enteral feedings will receive feedings at 10 cubic centimeters (cc) per hour, to be continued at this rate for 144 hours, provided that the participant remains on the ventilator. After the 144 hours, the feeding rate will be advanced to full-calorie rates. Participants assigned to initial full-calorie enteral feedings will receive feedings at 25 cc per hour, and the feeding rate will be increased by 25 cc per hour every 6 hours until the goal rate is reached. During enteral feedings, gastric residual volumes (GRVs) will be checked every 6 to 12 hours to assure acceptable levels. Participants will complete enteral feedings upon hospital discharge, Day 28 of treatment, death, or ability to achieve 48 hours of unassisted breathing. Blood pressure, heart rate, ventilation settings, and various blood factors will be measured during treatment. Phone-based follow-up assessments will occur at Months 6 and 12 after ICU discharge and will include measurements of health-related quality of life; psychological, neurocognitive, and physical activity outcomes; healthcare utilization; and mortality.