右美托咪定联合多巴胺对脑外科术后患者脑血流和脑氧代谢率的影响

Effect of Dexmedetomidine on Cerebral Blood Flow and Cerebral Metabolic Rate in Patients after Brain Surgery

目的脑外科术后患者常常因为各种原因而出现躁动、谵妄等不良反应,选择合适的镇静药物有助于避免并发症的出现,方便医护人员对其神志的判断,利于后续的治疗。因此分析研究多巴胺控制血压的基础上右美托咪定(dexmedetomidine,Dex)镇静对脑外科术后患者脑氧代谢率(CMRe)、脑血流量(CBF)等的影响,以便指导临床镇静药物的使用。方法选取25例脑外科术后即转入重症监护室的患者,根据格拉斯哥昏迷评分(GCS)将所有患者分为轻度脑损伤(G1)组,中度脑损伤(G2)组,重度脑损伤(G3)组。所有患者在多巴胺维持基础血压的前提下,静脉泵注Dex。分别在镇静前(t0)、镇静后90 min(t1)及停药后3 h(t2)测定大脑CBF,t0及t1时计算CMRe。多普勒超声仪经双侧椎动脉和颈内动脉测定CBF,根据股动脉及颈静脉球血样计算CMRe。同时记录患者各时点的呼吸频率、SpO2、PaCO2、心率、平均动脉压及Riker镇静躁动评分(SAS)。结果 Dex镇静前后,各组患者CBF差异无统计学意义(P>0.05)。与t0相比,t1时CMRe、CBF/CMRe及PaCO2均无明显改变(P>0.05)。RikerSAS评分在用药t1时明显低于t0(P<0.05)。结论脑外科术后的脑损伤患者,采用多巴胺控制血压的同时Dex镇静是安全可行且行之有效的,对脑损伤患者的CBF和CMRe无明显影响。

OBJECTIVE To investigate the effects of dexmedetomidine combined with dopamine on cerebral blood flow(CBF)and cerebral metabolic rate equivalent (CMRe) in patients after brain surgery. METHODS Twenty-five patients were transferred to the intensive care unit immediately after brain surgery were collected. Patients were divided into three groups, mildbrain injury group(G1), moderatebrain injury group(G2) and severe brain injury group(G3) according to Glasgow coma score (GCS). All patients were sedated with dexmedetomidine, dopamine was infused to maintain blood pressure at the level before treatment during the experiment. CBF was determined by measuring vertebral artery and internal carotid artery blood flow with color Doppler ultrasound at presedation (t0), 90 min of adminstration of dexmedetomidine (t1) and 3 h after discontinuing dexmedetomidine (t2). Blood samples from jugular bulb and femoral artery were taken at presedation and 90 min of adminstration of dexmedetomidine to determine CMRe. respiratory rate, pulse oxygen saturation, PaCO2, mean artery pressure, heart rate, and RikerSAS sedation score were recorded. RESULTS There was no difference in CBF at the three time points in each group (P>0.05). Neither did CMRe, CBF/CMRe and PaCO2 have any change between t0 and t1 (P>0.05). RikerSAS score at t1 was lower than presedation (P<0.05). CONCLUSION Dexmedetomidine combined with dopamine is safe and effective in brain injury patients without causing significant changes in CBF and CMRe.