肠内喂养 持续与间断.pptVIP

“ ” Controversies and Misconceptions in Intensive Care Unit Nutrition .. Although clinical data are sparse, intermittent bolus feeding has numerous potential advantages over continuous feeding including preservation of muscle mass; preservation of intestinal, hepatic, and gallbladder function; and improved glycemic control. Protein provided as a continuous infusion, especially in high doses, suppresses muscle synthesis. Whey protein (high in leucine) promotes greater muscle synthesis compared with casein or soy-based enteral formulas background Continuous enteral feeding of critically ill adults seemsto be the standardof care around the world.1 This is not physiologic and may be associated with complications and side effects. Experimental animal and human data have demonstrated the negative effects of continuous tube feeding on muscle synthesis, hepatic and intestinal structure and function, and multiple metabolic and endocrine effects when compared with intermittent bolus feeding, as detailed next. muscle synthesis Insulin and the branched-chain amino acid, leucine, play a critical role in muscle synthesis by activating AKT/protein kinase B and mammalian target of rapamycin (mTOR), respectively。 In humans a bolus of whey protein (high in leucine) results in the pulsatile release of insulin; a pulsatile increase in intramuscular leucine concentration; and an increase in the synthetic rate of muscle, which peaks at 90 minutes and returns to baseline at 180 minutes. organ dysfunction GLP-1, GIP, blood GIP and GLP-1 levels and insulin receptor phosphorylation and phosphatidylinositol- 3-kinase levels in liver and muscle were significantly reduced with continuous feeding as opposed to intermittent feeding Insul inresistance, hepatic steatosis, and hepatic inflammation were greater with continuous feeding. The incretins GIP and GLP-1 play an Important role in preparing the pancreas to handle incoming nutrient