Metabolism and Artificial Nutrition in the Critically Ill

The critically ill patient in intensive care often has to face signifi cant metabolic alterations caused directly by the illness or secondary by complications (i.e. infections, organ failure or sepsis). Situatio ns of rapidly evolving altered metabolism are maintained by or can tri gger complex hormonal reactions, which in turn promote further metabol ic derangements. Surgery or trauma patients and those afflicted by sep tic complications can present significant nitrogen loss with consequen t altered protein, carbohydrate or lipid metabolism. Further knowledge regarding the pathophysiology of metabolism and how abnormal stimulat ion of pyhsiological mechanisms can alter the consumption of principal energy substrates is necessary for optimal care of patients with alte red metabolic functions.