静脉应用右美托咪定对全麻甲状腺手术患者手术后早期恢复的影响

Effects of dexmedetomidine intravenous infusion on the early recovery process of patients undergoing thyroid surgery with general anesthesia

目的探讨静脉应用右美托咪定（dexmedetomidine，DEX）对全麻甲状腺手术患者手术后早期恢复的影响，并观察不同给药方法的可能作用。方法选择全麻下行择期甲状腺手术患者90例，年龄20岁-59岁，美国麻醉医师协会（ASA）分级Ⅰ～Ⅱ级，按随机数字表法分为3组：负荷量泵注组（D1组）、持续泵注组（D2组）和对照组（C组），每组30例。常规诱导气管插管后行机械通气。术中采用七氟醚吸入，维持平均动脉压mean arterial pressure，MAP）在±25％诱导前水平，脑电双频谱指数在45±10。间断静注芬太尼和顺式阿曲库铵维持麻醉。术前10min，D1组先单次静脉泵注DEX0．5μg／kg 10min，后持续静脉泵注生理盐水；D2组持续静脉泵注DEX0．5μg·kg^-1·h^-1；C组持续静脉泵注生理盐水；3组均在手术结束前30min时停止泵注。记录：用药情况；诱导前（T0）、术毕（T1）、拔管前（T2）、拔管时（T3）及拔管后1、3、5、10、15、30、45min（T4-T10）时的循环、呼吸和意识的变化；苏醒时间；拔管期间呛咳评分和镇静操动评分；拔管后30min时视觉模拟评分（visual analog scale，VAS）和Ramsay镇静评分；应用简易智力量表测定术前1d和术后1d的认知功能；副作用情况。结果①D1、D2、C组七氟醚用量分别为（49±9）MAC[最低肺泡有效浓度（minimum alveolar concentration）]·min、（61±14）MAC·min和（73±6）MAC·min，3组比较差异均有统计学意义（P〈0．05）；②与T0时比较，T2-T5时C组MAP和心率（heart rate，HR）显著升高（P〈0．05）；与C组比较，T1-T4、T6-T8时D1组和D2组MAP显著降低（P〈0．05），T3～T6时HR显著降低（P〈0．05）；③D1组和D2组呛咳评分、镇静躁动评分、VAS评分显著低于C组（P〈0．05）；④D1组和D2组躁动、高血压、心动过速的发生率显著低于C组（P〈0．05）；D1组术中心动过缓发生率（46．7％）显著高于D2组（26．7％）和C组（16．7％）（P〈0．05）；⑤3组患者的苏醒时间、Ramsay镇静评分和简易智力量表评分比较，差异无统计学意义（P〉0．05）.结论静脉给予DEX能保持甲状腺手术患者全麻恢复期血流动力学稳定，减少呛咳和躁动的发生，不影响苏醒和术后早期认知功能。DEX持续泵注致心动过缓较负荷量泵注更少。

Objective To evaluate the effects and feasibility of different intravenous infusion with dexmedetomidine （DEX） on the early recovery process of patients undergoing thyroid surgery with general anesthesia. Methods Ninety patients aged 20-59 years with American society of anesthesiologists physical status Ⅰ or Ⅱ , who were scheduled for elective thyroid surgery, were randomized into 3 groups： DEX loading dose intravenous infusion group （DEX 0.5 μg/kg in 10 min, followed by normal saline, n= 30, group D1）, DEX continuous intravenous infusion group （DEX 0.5 μg·kg^-1·h^-1, n=30, group D2） and control group （group C）. After induction with fentanyl, propofol and rocuronium, all patients were performed tracheal intubation and mechanical ventilation. Anesthesia was maintained with sevoflurane, fentanyl and cisatracurium were given at 40 min intervals until 30 min before the end of the operation. Patients in the 3 groups were all started intravenous infusion at 10 min before the operation and discontinued at 30 min before the end of the operation. During the operation the concentration of sevoflurane was varied to maintain mean artery pressure （MAP） within ±25% of the preinduction values and bispectral index within 45 ±10. The consumption of sevoflurane,the dosage of DEX, fentanyl and cisatracurium were observed. MAP, heart rate （HR）, pulse oxygen saturation and bispectral index were recorded at the time-points of before induction （T0）, terminal of operation （T1）, before extubation （T2）, immediately extubation （T3）, 1, 3, 5, 10, 15, 30, 45 min after extubation （T4-T10）. The recovery time from the end of the operation to spontaneous breath, eye opening, extubation and orientation were also recorded. The cough reflex scores and sedation-agitation scale during extubation, the visual analogue scale and Ramsay sedation scale at 30 min after extubation,the preoperative and postoperative cognitive function by using mini-mental state examination , and the incidences of side effects were assessed. Results （1） The consumption of sevoflurane of group D1 [ （49±9） MAC （minimum alveolar concentration）· min] and D2 [ （61 ± 14） MAC· min] were significantly lower than that of group C[（73±6） MAC·min]（P〈0.05）. （2） Compared with To, values of MAP and HR increased statistically at T2-T5 in group C （P〈0. 05）. Compared with group C, values of MAP at T1-T4, T6-T8 and HR at T3- T6 decreased statistically in group D1 and D2 （P〈0.05）. （3） The scores of cough reflex, sedation-agitation scale and visual analogue scale were significantly lower in group D1 and D2 than in group C （P〈0.05）. （±） The incidence of agitation, high blood pressure and tachycardia were significantly lower in group D1 and D2 than in group C （P〈0.05）. The bradycardia incidence of group D1（46.7%）during the operation were significantly higher than that of group D2 （26.7%） and group C（16.7%） （P〈0.05）. （5） There were no significant differences in recovery time, Ramsay sedation scale, mini-mental state examination scores among the 3 groups （P〉0.05）. Conclusions DEX intravenous infusion in patients undergoing thyroid surgery with general anesthesia can keep stable perioperative hemodynamics, relieve cough reflex, agitation incidence and level, while did not prolong recovery time and affect the early postoperative cognitive function. Its continuous intravenous infusion is an optimal choice than its loading dose intravenous infusion.