Early nutritional therapy: the role of enteral and parenteral routes

Early nutrition is defined as the initiation of nutritional therapy within 48 h of either hospital admission or surgery. However, optimal timing for initiation of nutritional therapy through either enteral or parenteral routes remains poorly defined with the existing data. We reviewed the recent literature investigating the role of early enteral and parenteral nutrition in critical illness and perioperative care.

Recent studies in both trauma/surgical and nonsurgical patients support the superiority of early enteral over early parenteral nutrition. However, late commencement of enteral feeding should be avoided if the gastrointestinal tract is functional. Both prolonged hypocaloric enteral feeding and hypercaloric parenteral nutrition should be avoided, although the precise caloric target remains controversial.

Early enteral nutrition remains the first option for the critically ill patient. However, there seems to be increased favor for combined enteral-parenteral therapy in cases of sustained hypocaloric enteral nutrition. The key issue is when the dual regimen should be initiated. Although more study is required to determine the optimal timing to initiate a combined enteral-parenteral approach, enteral nutrition should be initiated early and parenteral nutrition added if caloric-protein targets cannot be achieved after a few days.