Intermittent vs. continuous enteral feeding to prevent catabolism in acutely ill adult and pediatric patients

PURPOSE OF REVIEW: In clinical management of acutely ill adults and children, continuous enteral feeding (CEF), being considered the most tolerable approach, in comparison to other temporal patterns of nutrient administration (i.e. intermittent, cyclic and bolus), is the most frequently applied method. However, uncertainties remain about the most efficient approach to counteract protein catabolism. RECENT FINDINGS: In critically ill adults, protein loss is mainly driven by increased protein breakdown whereas, in pediatric patients, acute illness is mainly characterized by blunted regulation of protein synthesis and stunted growth. Kinetic studies in fed adult volunteers indicate that protein synthesis can be stimulated for a limited period only. However, continuous feeding persistently improves protein balance through a sustained suppression of protein breakdown. This leads to the hypothesis that CEF could be more anticatabolic than intermittent enteral feeding (IEF) in these patients. Differently from adults, experimental models of acute disease in growing animals have consistently indicated that IEF can improve protein anabolism more efficiently than CEF, mainly through protein synthesis stimulation. The scarce number of clinical studies in acutely ill adults or pediatric patients, mostly performed with inadequate methodology, could not define the best approach to maintain protein balance. SUMMARY: There is a need for pragmatic studies to directly compare the protein anabolic action of CEF and IEF using accurate methodologies, such as stable isotopes of amino acids, in both adult and pediatric patients with acute illness.