术中不同速率输注右美托咪定在全凭静脉麻醉中的量效关系研究

目的：以脑电双频指数（bispectral index，BIS）作为麻醉镇静程度指标，探讨不同速率输注右美托咪定（dexmedetomidine，DEX）对全凭静脉麻醉中丙泊酚用量，术中重要时点血液动力学及麻醉恢复质量的影响。方法：选择拟于全麻下行妇科腹腔镜手术的患者60例（ASAI～II级），根据DEX输注速率不同随机分为四组，即D1、D2、D3和D4组，每组15例，麻醉诱导前四组均给予负荷剂量DEX0．5μg·kg-1，10min输注完毕，继而四组分别以0．2、0．4、0．6和0．8μg·kg^-1·h^-1输注速度持续输注至冲洗腹腔。四组麻醉诱导方法相同，术中以BIS作为麻醉深度指标，根据BIS值调节丙泊酚血浆靶浓度维持麻醉。记录入室用药前（T0）、DEX负荷量输注后（T1）、气腹即刻（T2）、气腹后5min（T3）、气腹后30min（T4）、解除气腹后5min（T5）、拔喉罩即刻（T6）、拔喉罩后1min（T7）时收缩压（SBP）、舒张压（DBP）、心率（HR）、丙泊酚平均用量、苏醒时间、拔喉罩时间、拔喉罩后15rainOAA／s评分、术中及术后24小时内不良反应的发生情况。结果：①D2、D3、D4组丙泊酚平均用量较D1组明显减少（P〈0．05），D3、D4组丙泊酚平均用量较D：组明显减少（P〈0．05）。D3、D4组间差异无统计学意义（P〉0．05）。②与T0比较，Tl～T2时四组SBP、DBP、HR降低（P〈0．05），T3～T4时D3、D4组SBP、DBP、HR降低（P〈0．05），D1、D2组SBP、DBP无明显变化（P〉0．05），T5～T7时四组SBP、DBP、HR降低（P〈0．05）；D3、D4组在T3～T4时SBP、DBP较D1、D2组明显降低（P〈O．05），D1、D2两组间差异无统计学意义（P〉0．05），D3、D4两组间差异无统计学意义（P〉0．05）。③D4组苏醒时间、拔喉罩时间、较Dlq组明显延长（P〈0．05），D4组OAA／s评分较D1-3组明显降低（P〈0．05）。④D4组使用阿托品次数较D1-3组明显增多（P〈0．05），四组术中使用麻黄碱次数和术后24小时内恶心、呕吐、寒战差异无统计学差异（P〉0．05）。结论：在妇科腹腔镜手术中，DEX作为全身麻醉辅助用药，负荷剂量0．5μg·kg-1，术中持续输注速率0．4μg·kg-1·h-1可以有效降低丙泊酚用量，使围手术期的血流动力学保持平稳，不延长苏醒时间和拔喉罩时间，且不良反应更少，值得临床推广应用。

Dose-effect Relationship of the Dexmedetomidine at Different Infusing Rates in the Total Intravenous Anesthesia

Objective： To investigate the effect of different doses of dexmedetomidine （Dex） on propofol dosage and hemodynamics during important time points and anesthesia recovery quality in total intravenous anesthesia. Methods： 60 patients（ASA I~II） who were scheduled for elective through gynecologic laparoscopic surgery in general anaesthesia were randomly divided into four groups by the infusion rate of Dex：Group DI, D2, D3, D4, 15 cases were in each group. All the groups were received DEX 0.5μg·kg^-1 bolus 10 minutes before the anesthesia induction and then 0.2,0.4,0.6,0.8 μg·kg^-1·h^-1 by continuous infusion until flushing abdominal cavity.The same anesthetic induction method was used in the four groups. BIS was used as the index of depth of anesthesia, by which the target plasma concentration of propofol was adjusted to maintain the anesthesia. The systolic blood pressure （SBP）, diastolic blood pressure（DBP）, heart rate（HR） were recorded at time points pre-administration of Dex （To）, after Dex infusion （TI）, pneumoperitoneum （T2）, pneumoperitoneum after 5 min （Ta）, pneumoperitoneum after 30min （T4）, lifting of pneumoperitoneum after 5min （Ts）, extubation （T6）, 1 min after extubation （%）. The average consumption ofpropofol, recovery time, laryngeal mask extubation time, OAA/S sedation score 15min after laryngeal mask extubation and intraoperative and postoperative 24hours adverse reactions were recorded. Results： （1） Compared with group D, the propofol consumption in group D2, D3, D4 were significantly decreased （P〈0.05）. Compared with group D2, the propofol consumption in groupD3, D4 were significantly decreased （P〈0.05）. The difference between group D3 and group D4 was not statistically significant （P〉0.05）. （2）Compared with To, the SBP, DBP, HR were lower at T1-T2 in four groups（P〈0.05）, the SBP, DBP,HR were lower at T3-T4 in groupD3, D4（P〈0.05）, the SBP, DBP were unchanged at T3-T4 in group D1, D2 （P〉0.05）, the SBP, DBP, HR were lower at T6-T7 in four groups（P〈0.05）. The SBP, DBP in group D3, D4 were significantly lower during pneumoperitoneum （T3~ Ts） than group D1, D2 （P〈0.05）, the difference between group D3 and group D4 was not statistically significant （P〉0.05）, the difference between group D1 and group D2 was not statistically significant （P〉0.05）. （3）The recovery time and laryngeal mask extubation time extended in group D4,which was statistically significant compared with group D1-3 （P〈0.05）.Compared with group D1-3, OAA/S sedation score in group D4 significantly decreased（P 〈 0.05）.（4）Compared with groupD1-3,the use of atropinein group Dasignificantly increased（P 〈 0.05）.The intraoperative use of ephedrineand,shiver,nausea,vomiting during 24 hours postoperation was not different among the four groups （P〉0.05）. Conclusions： When Dex was used as a general anesthesia adjuvant during gynecologic laparoscopc surgery, its loading dose 0.5 μg·kg^-1, infusion rate of 0.4 μg·kg^-1·h^-1 may effectively decrease the dosage of propofol, stabilize hemodynamia during the perioperative period, not prolong the recovery time and laryngeal mask extubation time, decrease the adverse reactions, which was worthy of clinical application.