右美托咪定对重型颅脑外伤术后脑氧代谢的影响

Effects on Cerebral Oxygen Metabolism of Severe Traumatic Brain Injury after Operation Treated with Dexmedetomidine

【目的】研究右美托咪定对重型颅脑外伤(STBI)术后患者脑氧代谢的影响。【方法】采用前瞻性随机对照研究。入组患者按随机数字表法分为右美托咪定组(A组)和对照组(B组),最终纳入病例69例,A组37例,B组32例;所有患者术后即转入ICU,给予降低颅内压、维持呼吸、循环功能、防治感染、维持内环境稳定、营养支持、保护脏器功能等综合治疗;A组同时给予右美托咪定0.5μg/(kg·h)静脉泵入,持续72 h;所有患者持续监测心率(HR)、呼吸(R)、平均动脉压(MAP)、脉搏氧饱和度(Sp O2);颈内静脉逆行穿刺置管至颈静脉球部,并分别于入ICU后即刻(0 h)、12、24、48及72 h检测动脉及颈静脉球部血气分析,测得颈静脉球部血氧饱和度(Sjv O2),并计算颈内动脉与颈内静脉血氧含量差(AVDO2)及脑氧摄取率(CERO2);随访90 d,观察28 d病死率及90 d格拉斯哥预后评分(GOS);比较两组上述指标的差异性。【结果】入ICU即刻(0 h)两组HR、R、MAP、Sjv O2、AVDO2、CERO2比较无统计学差异(P>0.05);重复测量资料方差分析发现:A组HR、R、MAP整体水平均低于B组(均为P<0.001);随时间延长,A组患者HR、R、MAP均较B组明显下降(均为P<0.001);A组Sjv O2整体水平高于B组(P=0.005),AVDO2、CERO2整体水平均低于B组(P=0.035;P=0.001);随时间延长,A组患者Sjv O2较B组明显升高,而AVDO2明显降低(P=0.001;P<0.001)。A组90 d预后良好率明显高于B组(P=0.036)。【结论】右美托咪定可以降低STBI患者交感神经系统兴奋性,降低脑氧耗,改善脑氧代谢紊乱,从而发挥脑保护效应,改善患者临床预后。

[ 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, maintenaneerespiration, 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 eatheterizationretrograde 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 = O.O05;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.