The amount of artificial nutrition required to optimize outcomes in patients with acute lung injury (ALI) is unknown. To address this problem, the Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network, headed by Todd Rice, MD, MS, from VanderbiltUniversityinNashville,Tennessee,USA, conducted a prospective, randomized open-label trial comparing the effect of initial trophic enteral feeding vs. initial protocolized full enteral feeding for the first six days of mechanical ventilation in patients with ALI.

Patients within 48 hours of ALI onset and receiving mechanical ventilation were enrolled from 44 hospitals from January 2008 to March 2011. The feeding strategy intervention was continued until hospital day six. The full-feeding group received enteral nutrition advanced to goal as rapidly as possible; the trophic-feeding group received 10-20 kcal/h. A protocol specified holding parameters for high gastric residual volumes (>400 mL). Postpyloric tubes were used in less than 20% of patients.

According to the study, published in the Journal of the American Medical Association, 508 patients received trophic feeding and 492 patients received full feeding. Both groups were comparable at baseline. There was no difference between groups with regard to the primary endpoint of ventilator-free days; the trophic group averaged 14.9 days, the full group 15.0 days. Sixty-day mortality was not statistically different between the groups (23.2% vs. 22.2% in the trophic vs. full-feeding groups). No significant differences were found between groups in other secondary endpoints, including infectious complications and organ failures. Trophic feedings were associated with less gastrointestinal intolerance. The authors concluded that in patients with ALI, initial trophic feeding for up to six days did not improve outcomes compared with full enteral feeding.

Limitations in this study include possible reporting bias due to the open-label design, and the fact that most patients were treated in medical intensive care units. Underweight patients (i.e., malnourished) were excluded, and 60-day mortality might have been underestimated because patients discharged home were presumed to still be alive. Nevertheless, this rigorously conducted study showed that gastric feeding is feasible early in the course of treatment for ALI and is associated with fewer gastrointestinal complications, although no difference in outcomes is evident.

Concise Critical Appraisal is a regular feature authored by SCCM member Samuel M. Galvagno Jr., DO. Each installment highlights journal articles most relevant to the critical care practitioner.