右美托咪定复合硝酸甘油在鼻内镜手术控制降压中的效果和血流动力学影响

Efficacy of dexmedetomidine combined with nitroglycerin and the hemodynamic response in controlled hypotension during endoscopic sinus surgery

目的：比较右美托咪定复合硝酸甘油与单独使用硝酸甘油在鼻内镜手术控制降压中的出血量与对血流动力学的影响。方法：选择北京航天总医院2014年9—12月收入院的择期全麻下行鼻息肉切除鼻窦开放术的ASAI～Ⅱ患者40例，依据降压药物的差异将其随机分为两组：对照组（c组）单独使用硝酸甘油降压，右美托咪定组（D组）使用右美托咪定复合硝酸甘油降压，每组20例。两组均采用丙泊酚、舒芬太尼和维库溴铵诱导插管，术中采用丙泊酚与瑞芬太尼输注，间断给予维库溴铵全静脉维持麻醉。D组在诱导后给予右美托咪定1μg·kg-1，容量配置均为20mL，输注时间15min，C组在15rain输注等容量生理盐水。两组均在开始鼻腔消毒时开启硝酸甘油，起始剂量为1汕g·kg-1·min-1，根据术中血压调节输注速度，维持平均动脉压（MAP）为60～70mmHg。手术完成准备填塞止血棉时停止降压。记录两组患者入室后基线（TO）、开始降压前（T1）、降压10min（T2）、降压20min（T3）、降压40min（T4）、停降压后10min（T5）、拔管时（T6）和拔管后10min（T7）的MAP和心率（HR），并记录术中出血量、术野评分（Fromrne法）、降压期间所使用硝酸甘油的平均用量、拔管时间以及拔管后10rain的镇静评分。结果：与们比较，c组的HR仅在Tl和T5明显下降（P〈0．05），而D组的HR在其余各时点（T1～T7）均比TO明显降低（P〈0．05）。c组的MAP在T1一T5时间点与T0比较明显下降（P〈0．05），而在T6和T7时间点则恢复至术前水平；D组MAP在其余各时间点均比’r0明显降低且有统计学差异（P〈0．05）。与c组比较，D组HR在T1、降压期（T2～T4）及T6明显降低（P〈0．05）；D组的MAP在T1，T6和1v7明显低于c组，差异有统计学意义（P〈0．05），两组患者MAP在降压期间（T2，T3，T4）比较未见统计学差异。与C组比较，D组的手术出血量、术野评分、降压所用硝酸甘油的平均使用量均明显下降（P〈0．05），两组拔管时间未见统计学差异。D组在拔管后10min的镇静评分明显高于c组（P〈0．05）。结论：右美托咪定可以增强硝酸甘油的降压作用，联合使用比单独使用硝酸甘油可以明显减少出血，降低硝酸甘油的使用量。右美托咪定1μg·kg-1具有镇静作用，但并不延长拔管时间。

Objective： To compare the effects and hemodynamic responses of dexmedetomidine combined with nitroglycerin and nitroglycerin alone in the induced hypotension during endoscopic sinus surgery. Methods： Forty patients in Beijing Aerospace General Hospital from September to December 2014, ASA I or II, scheduled for endoscopic sinus surgery under general anesthesia, were equally randomly divided into two groups according to dif-ferent drugs for induced hypotension. Patients received either nitroglycerin alone or dexmedetomidine combined with nitroglycerin for controlled hypotension. Both groups were given propofol, sufentanil and vecuronium for induction, and general anesthesia was maintained with propofol and remifentanil. After induction, combination group received dexmedetomidine 1 μg kg-1 at 20 mL within 15 min, while the equal volume of saline was given in nitroglycerin group at the same infusion rate. When the operation began to sterilize the nasal cavity, nitroglycerin was adminis- trated at initial infusion of 1 μg kg-1 min-1 in both groups, and the infusion was adjusted according to the target MAP （60 -70 mmHg）. MAP and HR were measured at designed time-points as follows： baseline （T0）, before controlled hypotension （T1） , 10 rain （T2） , 20 min （ T3 ）, 40 min （T4） after controlled hypotension ; 10 min after end of controlled hypotension （TS） ; extubation （T6） and 10 min after extubation （T1）. Amount of bleeding, surgical field quality score （Fromme） , average usage of nitroglycerin, extubation time and the sedation score at 10 min after extubation were assessed. Results： Compared with TO, HR in nitroglycerin group was significantly lower only at T1 and 35, while HR in combination group was lower than TO at T1 - T7. MAP in nitroglycerin group was significantly decreased than TO at T1 - T5 （P 〈 0.05） ; meanwhile, MAP in combination group was lower than TO at other time-points （P 〈 0.05）. HR was significantly lower in combination group than in nitroglycerin group at T1, T2 - T4 （hypotension period ） and T6 （P 〈 0.05）. MAP in combination group was significantly lower than that in nitroglycerin group at T1, T6 and T7 （P 〈 0.05）. There was no significant difference in MAP at T2, T3 and T4 between the two groups. Amount of bleeding and surgical field quality score were significantly lower in com- bination group than in nitroglycerin group （P 〈 0.05）. The average usage of nitroglycerin was significantly less in combination group than in nitroglycerin group （P 〈 0.05 ）. The sedation score at 10 min after extubation was signif- icantly higher in combination group than in nitroglycerin group （P 〈 0.05）. No significant difference was observed in extubation time between the two groups. Conclusion： Compare to nitroglycerin alone, dexmedetomidine en- hances the effects of nitroglycerin during induced hypotension, and reduces blood loss and the use of nitroglycerin. Dexmedetomidine at the dose of 1 μg kg-1 can provide sedative effect and does not extend the extubation time.