Nutrition in the critically ill patient remains a controversial topic. Most clinicians have viewed nutrition as part of patient care but not as a therapeutic intervention. Recent studies have looked at type and timing of nutrition to determine whether they affect important clinical outcomes.
Large-scale, multicentre randomized trials have found that supplemental parenteral nutrition has a deleterious effect in comparison to enteral nutrition alone. Use of early parenteral nutrition in critically ill patients in whom enteral nutrition was contraindicated did not significantly improve clinical outcomes. Also, low-dose or trophic enteral nutrition has similar benefits with less gastrointestinal complications compared with early full dose caloric feedings. The timing of early nutrition has been defined in most large-scale studies as beginning within 48 h of intubation, though some earlier studies used a 24-h cut-off point with some improved outcomes.
Although not strong, the best available data suggest that critically ill patients should be started on enteral tube feeds within 48 h of intubation whenever possible. The use of parenteral nutrition should be limited within the first 6 days, and not used to augment caloric intake. Finally, similar benefits are seen in patients receiving minimal enteral feeds versus full caloric enteral nutrition.
aDivision of Pulmonary and Critical Care Medicine, Meharry Medical College
bDivision of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
Correspondence to Todd W. Rice, MD, MSc, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, T-1218 MCN, Nashville, TN 37232-2650, USA. Tel: +1 615 322 3412; fax: +1 615 343 7448; e-mail: firstname.lastname@example.org