摘要
目的观察右美托咪定对脑功能正常的重症监护病房(ICU)住院患者的脑血流量(CBF)、脑氧代谢率的相对数值(CMRe)等的影响。方法选择肠癌或骨肿瘤术后脑功能正常的ICU住院患者30例,美国麻醉医师学会分级Ⅰ或Ⅱ级,随机分入对照组和试验组,每组15例。对照组静脉注射负荷剂量的右美托咪定(1μg/kg,注射时间为10min)后以0.4μg·kg-1·h-1维持剂量注射2h,当患者的收缩压<90mmHg(1mmHg=0.133kPa)或舒张压<50mmHg时,经微量静脉输液泵静脉注射多巴胺维持血压至正常低值水平(90/50mmHg);试验组除与对照组使用相同剂量右美托咪定外,试验过程中经微量静脉输液泵静脉注射多巴胺维持患者的血压于用药前水平。采用多普勒超声仪经双侧颈内动脉和椎动脉测定大脑CBF,并采集颈内静脉和股动脉血样行血气分析计算CMRe。分别于用药前及用药70min时记录患者的CBF、CMRe、CBF/CMRe、脑氧摄取率(CEO2)、Ramsay镇静评分以及循环和呼吸指标。结果两组用药70min时的CBF和CMRe均较同组用药前显著降低(P值均<0.01)。用药前及用药70min时,两组间CBF和CMRe的差异均无统计学意义(P值均>0.05)。两组组间和组内比较,CBF/CMRe和CEO2的差异均无统计学意义(P值均>0.05)。对照组用药70min时的收缩压、舒张压、平均动脉压(MAP)均较同组用药前显著降低(P值均<0.01),用药前后心率、呼吸频率、脉搏血氧饱和度和动脉血二氧化碳分压的差异均无统计学意义(P值均>0.05);试验组用药前后各项循环和呼吸指标的差异均无统计学意义(P值均>0.05)。对照组用药前的CBF与MAP不相关(r=0.111,P>0.05),用药70min时的CBF与MAP呈正相关(r=0.570,P<0.05)。试验组用药前、用药70min时的CBF与MAP均不相关(r=0.113、0.024,P值均>0.05)。两组患者用药70min时的Ramsay镇静评分均显著高于同组用药前(P值均<0.01)。结论右美托咪定可减少脑功能正常的ICU住院患者的CBF并降低其CMRe。
Objective To observe the effects of dexmedetomidine on cerebral blood flow （CBF） and cerebral metabolic rate equivalent （CMRe） in patients with normal brain function in intensive care unit （ICU）. Methods Thirty postoperative patients in ICU, who suffered from colorectal cancer or bone tumor and had normal brain function and American Society of Anesthesiologists （ASA） grade I - II, were randomly divided into control group and experimental group （n = 15）. In the control group, a loading dose of dexmedetomidine （1 IJg/kg for 10 mins） was intravenously injected and followed by 0.4 μg · kg-1· h-1 maintenance dose for 2 h; dopamine was infused to maintain blood pressure to 90/50 mmHg （1 mmHg= 0. 133 kPa） once the systolic blood pressure （SBP） was less than 90 mmHg or diastolic blood pressure （DBP） was less than 50 mmHg. In addition to the same dose of dexmedetomidine in control group, in the experimental group dopamine was infused to maintain blood pressure at the level before treatment. CBF was determined by measuring bilateral internal carotid artery and vertebral artery with color Doppler ultrasound. Blood samples from jugular vein and femoral artery were taken to determine CMRe. CBF, CMRe, CBF/CMRe, cerebral extraction of oxygen （CEO2）, Ramsay sedation scores, circulation and respiratory parameters were recorded before sedation and at 70 min after adminstration of dexmedetemidine. Results Compared with those before sedation, CBF and CMRe were significantly decreased at 70 min after adminstration of dexmedetomidine in both groups （P〈0.01）. But there were no significant differences in CBF and CMRe between the two groups at the two time points （ P 〉 0. 05）. There were no significant differences in CBF/CMRe and CEO2 neither between the two groups nor within groups at the two time points （P〉0.05）. In the control group SBP, DBP and mean arterial pressure （MAP） at 70 mins after administration of dexmedetomidine were significantly lower compared with those before dexmedetomidine adiministration （P〈0.01）, but heart rate, respiration rate, SpO2 and pace2 had no significant changes （P〉0. 05）. There were no significant differences in circulation or respiratory parameters between pre-sedation and 70 min after adminstration of dexmedetomidine in experimental group （ P〉0. 05）. CBF was not correlated with MAP before sedation （ r = 0.111, P〉0. 05）, while it was positively correlated with MAP at 70 mins after adminstration of dexmedetomidine （r--0. 570, P〈0. 05） in control group. CBF was not correlated with MAP before and after sedation in experimental group （r=0.113 and 0. 024, P;0.05）. Ramsay sedation scores at 70 mins after adminstration of dexmedetomidine were significantly higher than those before sedation in both groups （P〈0.01）. Conclusion Dexmedetomidine can decrease CBF and CMRe in patients with normal brain function in ICU.
出处
《上海医学》
CAS
CSCD
北大核心
2012年第12期1017-1020,共4页
Shanghai Medical Journal
关键词
右美托咪定
脑血流量
脑氧代谢率
多普勒超声
Dexmedetomidine
Cerebral blood flow
Cerebral metabolic rate equivalent
Doppler ultrasound
