盐酸右美托咪定对脑额叶α_1和θ波频率的影响

Effects of dexmedetomidine on α_1-band and θ-band frequencies of frontal lobe

目的探讨静脉滴注盐酸右美托咪定对大脑额叶α_1和θ波频率的影响。方法择期下肢手术行椎管内麻醉患者60例,随机分为观察组和对照组各30例。麻醉前,观察组静脉滴注盐酸右美托咪定0.3μg/kg,对照组静脉滴注等体积生理盐水;2组均采用腰-硬联合阻滞麻醉。入室后行定量脑电图监测至手术结束,选取入室5 min(T_0)、给药30 min(T_1)、手术结束(T_2)3个时间点前后无伪差脑电图60s,观察并记录2组患者大脑左、右额叶α_1和θ波频率。结果 T_0、T_1时,2组左、右侧额叶θ和α_1波频率比较差异无统计学意义(P>0.05);T_2时,观察组左、右侧额叶α_1波频率[(12.44±1.71)、(11.89±1.51)Hz]高于对照组[(9.62±1.05)、(9.15±1.29)Hz],θ波频率[(4.96±0.75)、(5.23±0.83)Hz]低于对照组[(6.78±0.62)、(6.99±0.97)Hz](P<0.05);观察组T_1时左、右侧额叶α_1波频率[(10.06±1.15)、(10.02±1.43)Hz]低于T_0时[(12.30±1.59)、(12.03±1.43)Hz],θ波频率[(7.03±1.01)、(7.07±0.69)Hz]高于T_0时[(4.69±0.69)、(5.24±1.03)Hz](P<0.05),T_2时左、右侧额叶α_1、θ波频率与T_0时比较差异均无统计学意义(P>0.05);对照组左、右侧额叶T1时α_1波频率[(9.73±1.22)、(9.25±1.37)Hz]低于T_0时[(11.70±1.07)、(11.50±1.70)Hz],θ波频率[(6.59±0.81)、(6.96±0.78)Hz]高于T_0时[(4.75±0.76)、(4.90±0.85)Hz](P<0.05),T_2时α_1波频率低于T0时,θ波频率高于T_0时(P<0.05);2组围术期用药比率、手术时间、术中失血量及术中输液量比较差异均无统计学意义(P>0.05)。结论静脉滴注小剂量(0.3μg/kg)盐酸右美托咪定,可使下肢手术椎管内麻醉患者大脑额叶的α_1波频率升高,θ波频率降低;监测定量脑电图有助于术后认知功能障碍的及时发现。

Objective To compare the effect of dexmedetomidine on α_1-band and θ-band frequencies of frontal lobe.Methods Sixty patients undergoing elective lower limbs surgery were randomly divided into observation group and control group,with 30 patients in each group.Before combined spinal-epidural anesthesia,observation group was intravenously infused with 0.3μg/kg of dexmedetomidine and control group was intravenously infused with the equivalent volume of normal saline.Both groups were monitored the quantitative electroencephalography from the beginning to the end of surgery.The θ-band and α_1-band frequencies on the frontal lobes for 60 swithout artifact were observed and recorded at the time points of 5 min after entering the operating room(T_0),30 min after administration(T_1)and at the end of the operation(T_2).Results There were no significant differences in the frequencies of α_1-band and θ-band on the left and right frontal lobes both at T_0 and T_1 between two groups(P>0.05).The frequencies of α_1-band on the left and right frontal lobes at T_2 were significantly higher in observation group((12.44±1.71),(11.89±1.51)Hz)than those in control group((9.62±1.05),(9.15±1.29)Hz),and the frequencies of θ-band((4.96±0.75),(5.23±0.83)Hz)were significantly lower than those in control group((6.78±0.62),(6.99±0.97)Hz)(P<0.05).The frequencies of α_1-band on the left and right frontal lobes in observation group at T_1((10.06±1.15),(10.02±1.43)Hz)were significantly lower than those at T_0((12.30±1.59),(12.03±1.43)Hz),the frequencies of θ-band at T_1((7.03±1.01),(7.07±0.69)Hz)were significantly higher than those at T_0((4.69±0.69),(5.24±1.03)Hz)(P<0.05),and there were no significant differences in the frequencies of α_1-band and θ-band on the left and right frontal lobes at T_2 in comparison with those at T_0 in observation group(P>0.05).The frequencies of α_1-band on the left and right frontal lobes at T_1((9.73±1.22),(9.25±1.37)Hz)were significantly lower than those at T_0((11.70±1.07),(11.50±1.70)Hz),and the frequencies of θ-band on the left and right frontal lobes at T_1((6.59±0.81),(6.96±0.78)Hz)were significantly higher than those at T_0((4.75±0.76),(4.90±0.85)Hz)in control group(P<0.05).The frequency of α_1-band was significantly lower and the frequency of θ-band was signigicantly higher at T_2 than that at T_0 respectively in control group(P<0.05).There were no significant differences in the proportion of drug use,operation lasting time,intraoperative blood loss and intraoperative infusion volume between two groups(P>0.05).Conclusion Intravenous infusion of low-dose dexmedetomidine(0.3μg/kg)can increase the α_1-band frequency and decrease θ-band frequency on the frontal lobes in patients undergoing lower limbs surgery under combined spinal-epidural anesthesia,and monitoring quantitative electroencephalography is helpful for the detection of postoperative cognitive dysfunction in time.