[Critically ill patient enteral nutrition in the 21st century].

In order to make estimations on the evolution and near future of enteral nutrition in critically ill adult patients, we have revised the current clinical practices based on the latest guidelines for the provision and assessment of enteral nutrition support therapy. Once revised the suggested guideline recommendations we proceed to discuss the major recently published studies concerning these guidelines. Finally, we commented on several uncertainty areas highlighting priorities for clinical research in the near future. These uncertainty areas were as follows: administration methods of enteral nutrition, gastric residual volume monitorization, other aspects of gastrointestinal tolerance, protein requirements, glycemic monitorization and diabetic specific diets, immune-modulating formulas, permissive underfeeding or trophic enteral nutrition, supplementary nutrition and muscle wasting.