THE RELATIONSHIP BETWEEN HORMONAL MEDIATORS AND SYSTEMIC HYPERMETABOLISM AFTER SEVERE HEAD-INJURY

The relationships of hormonal mediators to the systemic hypermetabolis m and catabolism of head injury were studied in 15 patients with sever e head injuries. Resting energy expenditure (REE), urinary nitrogen ba lance, and plasma glucose concentration were measured daily for the fi rst 2 weeks after injury as the major indicators of hypermetabolism. T hese dependent variables were correlated with daily measurements of ur inary epinephrine, norepinephrine, metanephrine, normetanephrine, dopa mine, and cortisol, and with plasma levels of insulin, glucagon, and C -reactive protein. Urinary catecholamine and cortisol excretion were m arkedly elevated in these patients throughout the 2 weeks of study. Ca techolamine excretion peaked between days 7 and 10, whereas cortisol e xcretion tended to be highest on day 5 after injury. Urinary levels of norepinephrine, normetanephrine, and cortisol were highest in the two patients with Glasgow Coma Scale scores of 4. Plasma insulin and gluc agon concentrations were elevated on day 1 after injury and tended to increase throughout the 2-week period of study. The variables signific antly associated with REE were the severity of injury, reflected by th e GCS score, the urinary excretion of norepinephrine during the first 2 days after injury, and the urinary excretion of epinephrine and nore pinephrine during days 3 to 7 after injury. A negative nitrogen balanc e was associated with the urinary excretion of epinephrine and norepin ephrine, with caloric balance, and with plasma C-reactive protein duri ng days 1 and 2 after injury. During days 3 to 7, a negative nitrogen balance was associated with the urinary excretion of epinephrine and n orepinephrine and with caloric balance, and during days 8 to 14, a neg ative nitrogen balance was associated primarily with urinary cortisol excretion.