不同辅助用药对针药复合麻醉下心内直视手术呼吸循环功能的影响

Effect of Dexmedetomidine and Midazolam on Respiration and Circulation Functions in Patients Undergoing Open Heart Surgery under Acupuncture-assisted General Anesthesia

目的：观察右美托咪啶和咪唑安定作为辅助用药在针药复合麻醉下行心内直视手术中对呼吸和循环功能的影响。方法：针药复合麻醉下行心内直视手术60例，随机分为右美托咪啶组30例（右美托咪啶，负荷剂量1μg／kg，维持量0．2～1μg·kg^-1·h^-1）和咪唑安定组30例（咪唑安定，负荷剂量0．05mg／kg，维持量0．01～0．03mg·^-1·h^-1）。两组均采用针刺辅助麻醉，针刺穴位为双侧云门、中府、列缺、内关，手术过程中电针持续刺激。比较两组手术不同时段（基础值T0、切皮时T1、劈胸骨时T2、建立体外循环前T3、心脏复跳后T4、停体外循环后T5、出室时T6）动脉氧分压（PaO2）、动脉二氧化碳分压（PaCO2）、动脉血氧饱和度（SPO2）、平均动脉压（MAP）、心率（HR）的变化，进行麻醉效果评分，并比较两组自主呼吸恢复时间和苏醒时间的差异。结果：在呼吸功能方面，右美托咪啶组和咪唑安定组在T1、T2、T3和T6 4个时间点上PaO2、PaCO2、SPO2两组间差异有统计学意义（P〈0．05），且右美托咪啶组各时间段相对变异较小（P〉0．05），而咪唑安定组波动较大（P〈0．05）。循环方面，两组MAP组间、组内比较差异均无统计学意义（P〉0．05）；右美托咪啶组T1-6的HR明显低于本组T0时，并低于同时段咪唑安定组（P〈0．05），咪唑安定组T1-6的HR与T0比较明显增加（P〈0．05）。右美托咪啶组麻醉效果好于咪唑安定组（P〈0．05），自主呼吸恢复更快（P〈0．05），两组苏醒时间的差异无统计学意义（P〉0．05）。结论：右美托咪啶作为辅助用药在针药复合麻醉下行心内直视手术中麻醉效果更为满意，对呼吸及循环的影响小。

Objective To evaluate the effect of Dexmedetomidine and Midazolam on respiratory and circulation in patients experiencing open heart surgery under acupuncture-assisted general anesthesia. Methods Sixty patients undergoing open heart surgery （cardiac valve replacement surgery and aortic valve replacement surgery） were randomly and equally divided into Dexmedetomidine （D） and Midazolam （M） groups. Electroacupuncture （EA） was applied to bilateral Yunmen （LU 2）, Zhongfu （LU 1）, Lieque （LU 7） and Neiguan （PC 6）. For patients of group D, Dexmedetomidine （i. v., loading dose： 1 μg/kg, and succedent dose： 0.2- 1 μg·kg^-1·h^-1 ） was given. For patients of group M, Midazolam （i. v., loading dose： 0.05 mg/kg, succedent dose： 0.01t0.03 mg · kg^-1· h^-1） was given. Arterial oxygen pressure （PaO2）, arterial carbondioxide tension （PaCO2）, 02 saturation （SPO2）, mean arterial pressure （MAP）, heart rate （HR）, anesthetic effect, time of spontaneous breathing recovery, and time of resuscitation were recorded before operation （T0）, immediately after skin incision （T1）, immediately after sternotomy （T2）, before suspension of cardiopulmonary bypass （CPB, T3 ）, immediately after cardiac re-beating （T4）, immediately after CPB cessation （T3）, and at the end of surgery （T6）. Results Before operation, no significant differences were found between the group D and M in the levels of PaO2, PaCO2 and SPO2 （P〉0.05）. The PaO2 and SPO2 levels after skin incision, sternotomy, before suspension of CPB and at the end of surgery were significantly lower in group M than in group D （P〈0.05）, while the levels of PaCO2 after skin incision, sternotomy, before suspension of CPB and at the end of surgery, and HR after skin incision, sternotomy, before suspension of CPB, after heart re-beating,after CPB cessation and at the end of surgery in group M were considerably higher than those in group D （P〈0.05）. in addition, the time of spontaneous breathing recovery of group M was signifi- cantly later than that of group D （ P〈0.05）. No significant differences were found between the two groups in MAP levels at the 6 time-points during surgery, in the PaO2, PaCO2 and SPO2 levels at the time-points of post-cardiac re-beating, and after CPB cessation （P〉0.05）. It suggested that the respiration and circulation states in group D were more smoothly than those in group M. There was no significant difference between the two groups in the time of resuscitation （P〈0.05）. Conclusien Dexmedetomidine is superior to Midazolam in analgesia, and improving respiration and circulation functions for open heart surgery patients under acupuncture-assisted general anesthesia.