Abstract: 【Objective】 To investigate the effects on cerebral oxygen metabolism of severe traumatic brain injury after operation treated with dexmedetomidine. 【Methods】 A prospective randomized controlled study was conducted. 69 patients with severe traumatic brain injury after operation were divided randomly into dexmedetomidine group (group A) with 37 cases andcontrol group (group B) with 32 cases. All patients were transferred into ICU after operationimmediately

and were given combined therapy

such as reducing intracranial pressure

maintenancerespiration

prevention of infection

nutritional support

protection the function oforgans and so on. The patients of group A were also given dexmedetomidine with 0.5 μg/(kg·h) injected intravenously for 72 h. Heart rate (HR)

respiratory (R)

mean arterial pressure (MAP)

pulse oxygen saturation (SpO2) were monitored and the internal jugular vein catheterizationretrograde to the jugular bulb in all patients. The blood gas analysis of artery and jugular venous bulb were detected at 0 h

12 h

24 h

48 h

72 h after transferred to ICU. The jugular bulb venous oxygen saturation(SjvO2) was measured and the arterial to jugular venous oxygen content difference(AVDO2) and cerebral oxygen extraction(CERO2) were calculate. The 28-day mortality and Glasgow outcome score(GOS) after 90 days of surgery were recorded to examine effect of theraphy. 【Results】 There was no significant difference in HR

MAP

R

SjvO2

AVDO2

CERO2 between two groups at 0 h(P > 0.05). The overall level of HR

R and MAP of group A was lower than that of group B(all P < 0.001). The levels of HR

R and MAP of group A were significantly decreased with the time prolonged (all P < 0.001). The overall level of SjvO2 of group A was higher

while AVDO2 and CERO2 were lower than that of group B (P = 0.005;P = 0.035;P = 0.001).The SjvO2 of group A was significantly raised while AVDO2 of group B was significantly decreased with the time prolonged (P = 0.001; P < 0.001). Rate of good prognosis in group A was significantly higher than that in group B(P = 0.036). 【Conclusion】 Treated with dexmedetomidine on severe traumatic brain injury after operation could reduce the excitability of the sympathetic nervous system

improve the cerebral oxygen metabolism disorder

decrease cerebral oxygen consumption and play cerebral protective roles.