Cortisol response to corticotropin stimulation in trauma patients: influence of hemorrhagic shock.

BACKGROUND: An abnormal adrenocortical function and a vasopressor dependency have been demonstrated during septic shock. Because trauma and hemorrhage are the leading causes of noninfectious inflammatory syndromes, the goal of this study was to assess the adrenal reserve of trauma patients and its relation with clinical course.
METHODS: Cortisol response to an intravenous corticotropin bolus was obtained in 34 young trauma patients (Injury Severity Score =29.1 +/- 7.3) at the end of the resuscitative period ("early phase") and at the end of the first posttraumatic week ("late period"). Cortisol response less than +9 g/dl defined an impaired adrenal function, and the corresponding patient was called a nonresponder. According to the early response, hemorrhagic shock, circulating interleukin-6, need for vasopressor therapy, subsequent organ dysfunction and infection, and outcomes were studied.
RESULTS: Sixteen patients (47%) were nonresponders at the end of the early phase. Hemorrhagic shock was more frequent (69 vs. 28%; = 0.037) and interleukin-6 concentrations were higher (728 +/- 589 vs. 311 +/- 466 pg/ml; = 0.048) in these patients. The early cortisol responses were negatively correlated with the concomitant interleukin-6 serum concentrations (r(2) = 0.298; = 0.003). Four early nonresponders (and shock patients) remained nonresponders during the late phase (25%). Morbidity and mortality were similar in early nonresponders and responders. The duration of norepinephrine treatment and the total amount of infused drug were significantly higher in early nonresponders.
CONCLUSIONS: A sustained impairment of adrenal reserve is frequently observed in trauma patients. This abnormal cortisol response to corticotropin stimulation is related with the inflammatory consequences of hemorrhagic shock and is followed by a prolonged vasopressor dependency.