Answer: b, c A broad spectrum of metabolic abnormalities become apparent in sepsis and the systemic inflammatory response syndrome following shock. Disruption of the normal cycles of carbohydrate, lipid, protein, and oxygen metabolism occur as hypermetabolism develops. Through the Cori cycle, lactate from the periphery is shuttled back to the liver, where it is used in the production of glucose. Because pyruvate is converted to alanine in the periphery, flux of alanine also contributes to hepatic gluconeogenesis. The glycolytic oxidation of glucose to pyruvate and its subsequent glugoneogenic regeneration from lactate is an inefficient cycling of substrate. There is no net energy production, but heat is released in significant quantities. Alterations in lipid metabolism cause a progressive rise in the serum triglyceride level as a result of less efficient clearance of exogenous triglycerides coupled with increased hepatic lipogenesis. Profound alterations in protein and amino acid metabolism develop with characteristic changes in amino acid levels, nitrogen balance, and skeletal muscle mass. Initially levels of the branch chain amino acids are reduced, whereas those of the aromatic amino acids are elevated. There is an increase in the oxidative metabolism of protein to meet energy needs and a tremendous mobilization of nitrogen with net negative nitrogen balance. The branch chain amino acids are preferentially utilized in the TCA cycle to maintain an activity that otherwise would be lost from the diminished entry of carbohydrate-and fatty acid-generated acetyl coenzyme A. This results in reduced serum level of leucine, isoleucine and valine