Metabolic responses of the critically ill patient.

The care of the critically ill patient has become the point of convergence for substrate and energy metabolism, vital organ support, and cell biology. This article includes a brief review of normal metabolism and its endocrine regulation. The metabolic response to injury is reviewed with special attention to insulin resistance. The metabolic response to infection is considered in the light of rapidly emerging information on inflammatory mediators. Finally, brief attention is given to microcirculation and pericellular fluid as sites of metabolic regulation that have the potential for contributing to each of the three converging disciplines.