Hypocortisolism Following Acute Traumatic Brain Injury And Its Clinical Significance

Objective To investigate the serum status of total cortisol(TC), corticoster-oid-binding-globulin (CBG), free cortisol (FC) and free cortisol index (FCI) within14days after acute traumatic brain injury(TBI), and to find out the functional status of adrenal cortex, then help to guide clinical administration of glucocorticoids(GCs).Methods The research was carried out in neurosurgical department of General Hospital, Tianjin Medical University and neurosurgical department of Jinghai Hospi-tal in Tianjin. From January2007to February2008,38TBI patients with an admit-ting post-trauma period within24h were included in this study,30non-stress indi-viduals were studied as contrast. Serum status of TC and CBG was measured by ra-dioimmunoassay, FC and FCI was calculated by Coolens equation. Data were ana-lyzed with SPSS16.0,p<0.05was considered statistical significance. So the dynamic changes of the related hormones after different degrees of acute TBI was elucidated, meanwhile, adrenal cortex function was evaluated in these patients.Results In most patients of this group, within24h following acute TBI, TC, FC and FCI were higher than non-stress contrast(P<0.05), then dropped gradually, and returned to normal level about14days later. Adrenal insufficiency(AI) was observed in9patients,7patients (77.8%) of them showed poor outcome; there was no adrenal insufficiency in the other29patients during the research period, but1patients(3.4%) of them showed poor outcome. The incidence of the poor prognosis between the two group had statistical significance (P<0.05), so the occurrence of the AI was one of the key factors leading to poor prognosis.Conclusions Compared with control groups, TC, FC and FCI were higher and reached a peak in mild, moderate, and severe group after acute traumatic brain in-jury(TBI). TC were higher in mild, moderate, and severe injured group, especially in severe group. FC were higher in severe, moderate, and mild injured group. FCI were higher in severe and moderate injured group. TC, FC and FCI elevated rapidly, then decreased gradually, returned to normal level on day14after acute traumatic brain injury(TBI). The level of TC in favorable outcome group returned to normal range quicker than poor outcome group, nearly2days later. All patients didn’t appear AI on the1st and3rd day, but the AI incidence rate attained the peak(77.7%) on the7th day, and reduce gradually later on.Al occurrence closely related to bad outcomes. The AI most occur on the7th day after acute traumatic brain injury(TBI); In TBI earlier period,TC、FC were significant higher in different damaged groups, during this high-level condition, high dose GCs chemotherapy, further raising the GCs level in the body, can not necessarily strengthen the GCs nerve protection function, and instead, probably cause apoptosis side effects. Therefor, in earlier period, no hypocortisolism, the high dose GCs che-motherapy should be carefully considered. Blood TC, especially FC dynamic meas-uring can better objectively reflect patient physical stress condition, adrenocortical function and active cortisol, avoiding unnecessary GCs application. If patients have hypocortisolism or other definite application indication, do not inhibit GCs applica-tion. at this time, rational therapy to the AI, may act as a key role to improve a TBI patient outcome.