Metabolic response to severe surgical illness: overview

Severe surgical illness results in metabolic responses that mobilize substrate (amino acids and fatty acids) from body stores to support vital organs, enhance resistance to infection, and ensure wound healing. Central to this process is the redistribution of body protein, which moves from skeletal muscle to support the central viscera. If unsupported, this protein-wasting state could result in prolonged convalescence, diminished immunity, and poor wound healing. Present evidence suggests that the central nervous system plays a major role in regulating this protein catabolic response. Infusing exceedingly small quantities of the proinflammatory cytokines into the brain can mimic injury responses, and central cytokine blockade may be one therapeutic approach to attenuating these responses safely in the future. Additional evidence also demonstrates that the function of the hypothalamus and anterior pituitary is dampened during the later stages of severe surgical illness, and the possibility of hormonal replacement therapy needs to be explored.