Assessment of the effect of continuous sedation with mechanical ventilation on adrenal insufficiency in patients with traumatic brain injury.

The aim of this study was to assess the effect of continuous propofol sedation plus prolonged mechanical ventilation on adrenal insufficiency (AI) in patients with traumatic brain injury (TBI). Eighty-five adult patients diagnosed with moderate TBI (Glasgow Coma Scale (GCS) score 9-13) from October 2011 to October 2012 were included in this prospective study. The patients comprised three groups: no mechanical ventilation and sedation (n=27), mechanical ventilation alone (n=24) and mechanical ventilation plus sedation (n=34). The low-dose short Synacthen test was performed at 8:00 on the first, third, and fifth days after TBI. Logistic regression analysis was performed to identify factors affecting the use of mechanical ventilation and sedation, and the incidence of AI. On the fifth day after injury, the mean baseline cortisol and simulated cortisol levels were significantly lower in the mechanical ventilation plus sedation group compared with the other two groups. Multivariate regression analysis showed that the Acute Physiology and Chronic Health Evaluation (APACHE) score was independently associated with treatment with mechanical ventilation and sedation compared to mechanical ventilation alone. Furthermore, hypoxemia on admission and shock were associated with the development of AI. The findings showed that sedation is associated with an increased incidence of AI. Patients with TBI who are treated with continuous sedation should be monitored for AI carefully.