Endocrine abnormalities in critical care patients with moderate-to-severe head trauma: Incidence, pattern and predisposing factors

Objective: To investigate the incidence and type of endocrine abnormalities in critical care patients with traumatic brain injury (TBI) and to examine their relationships to possible predisposing factors. Design: Prospective study. Setting: General intensive care unit in a university hospital. Patients and participants: Thirty-four TBI patients (27 men, 7 women), having a mean age of 37±16 years, were studied after weaning from mechanical ventilation. Interventions: Baseline endocrine assessment was carried out by measuring cortisol, corticotropin, dehydroepiandrosterone sulfate, free thyroxine, thyrotropin (TSH), testosterone, oestradiol, follicle stimulating hormone (FSH), luteinizing hormone, prolactin, growth hormone and insulin-like growth factor I. Dynamic evaluation was performed by human corticotropin releasing hormone and growth hormone releasing hormone in all patients. Male patients underwent additional investigation with gonadotropin-releasing hormone. Severity of neurological derangement was graded according to Glasgow Coma Scale (GCS), Marshall Computerized Tomographic Classification and intracranial pressure (ICP) levels. Measurements and results: Eighteen of the 34 patients (53%) had an abnormal result in at least one hormonal axis tested, with cortisol hyporesponsiveness and gonadal dysfunction being equally common, affecting 24% of patients. Endocrine abnormalities were associated with a higher brain CT-scan classification score (p=0.02). The GCS on admission correlated positively with baseline FSH (r=0.37, p=0.03), peak FSH (r=0.41, p=0.03), testosterone (r=0.44, p=0.02) and TSH (r=0.39, p=0.03). There were no relations between ICP _max and any baseline or dynamic hormone measurements. Conclusions: Patients with TBI receiving critical care show changes in their neuroendocrine responses, which depend upon clinical and radiological measures of head injury severity. Most common abnormalities include cortisol hyporesponsiveness and hypogonadism.