[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): indications, timing and routes of nutrient delivery].

This article discusses basic features of nutritional support in critically-ill patients: general indications, the route of administration and the optimal timing for the introduction of feeding. Although these features form the bedrock of nutritional support, most of the questions related to these issues are lacking answers based on the highest grade of evidence. Moreover, prospective randomized trials that might elucidate some o f these questions would probably be incompatible with good clinical practice. Nevertheless, nutritional support in critically-ill patients unable to voluntarily meet their own nutritional requirements is currently an unquestionable part of their treatment and care and is essential to the successful management of their illness.