Carbohydrate Metabolism
  • Blood glucose concentrations increase after trauma:
    • Stimulated by cortisol and catecholamine
    • Due to increased hepatic glycogenolysis and gluconeogenesis
    • Peripheral glucose utilisation also decreases
    • Increase in concentration proportional to the degree of injury
  • Hyperglycaemia persists due during catabolic phase:
    • Usual homeostatic mechanisms ineffective
    • Hormones continue to promote glucose production
    • Relative lack of insulin and peripheral insulin resistance observed
Protein Metabolism
  • Protein catabolism occurs to mobilise amino acids:
    • Stimulated by cortisol
    • Amino acids used for energy or converted to acute-phase proteins
  • Predominantly skeletal muscle is broken down:
    • Results in marked wasting and weight loss
  • Visceral protein also catabolised:
    • Can predispose to organ dysfunction
Fat Metabolism
  • Increased lipolysis mobilising triglycerides to glycerol and fatty acids
  • Plasma levels may remain unchanged:
    • Glycerol acts as substrate for gluconeogenesis in the liver
    • Fatty acids re-esterized converted to ketone bodies
  • Stimulated by cortisol, catecholamines and growth hormone