摘要目的：评价右美托咪啶复合罗哌卡因用于剖宫产硬膜外麻醉中的效果和对新生儿的影响。方法选择2012年1月至2013年3月南京医科大学第一附属医院单胎足月妊娠拟在硬膜外麻醉下行子宫下段剖宫产术的患者60例。采用随机数字表法，将患者分为右美托咪啶复合罗哌卡因组（ RD组）、芬太尼复合罗哌卡因组（ RF组）和生理盐水复合罗哌卡因组（ RN组），每组20例。硬膜外穿刺成功并排除脊麻后，RD组给予0．75％罗哌卡因15 ml复合右美托咪啶1μg／kg，RF组给予0．75％罗哌卡因15 ml复合芬太尼1μg／kg，RN组给予0．75％罗哌卡因15 ml复合0．9％生理盐水2 ml。记录麻醉前（T0）、硬膜外注药完毕后10 min（T1）、30 min（T2）和术毕（T3）4个时点的平均动脉压（ MAP）和心率（ HR）。记录硬膜外阻滞起效时间、最高平面及达最高平面的时间，记录硬膜外阻滞持续时间和感觉阻滞时间。记录患者的Bromage分级和Ramsay镇静评分，记录术中牵拉反应程度。胎儿娩出后，抽取脐静脉血进行血气分析，并记录新生儿1、5 min时的Apgar评分。结果3组患者各时点间MAP、HR和Bromage分级比较差异无统计学意义（P＞0．05）。与RN组比较，RD组和RF组的起效时间、达最高阻滞平面时间缩短[（6．3±2．4）、（8．7±2．3） min 比（10．9±2．7） min，（11．5±3．9）、（16．2±4．6） min 比（19．8±5．2） min，P＜0．05]，阻滞持续时间、感觉阻滞时间延长[（22．5±4．6）、（18．5±3．9）min 比（13．5±3．8）min，（415±92）、（355±86）min 比（273±68）min， P＜0．05]，最高阻滞平面高，镇静程度高，术中牵拉反应轻，RD组寒战的发生率低（5％比40％，P＜0．05），RF组头晕的发生率高（20％比0％，P＜0．05）。与RF组比较，RD组的起效时间、达最高阻滞平面时间缩短，阻滞持续时间、感觉阻滞时间延长，安静合作程度高，嗜睡发生率低。3组脐静脉血气分析、新生儿出生后1 min和5 min时的Apgar评分的比较差异均无统计学意义（均P＞0．05）。结论罗哌卡因复合右美托咪啶可缩短硬膜外麻醉起效时间、延长感觉阻滞时间、增加术中产妇安静合作程度、降低术中牵拉反应和抑制寒战的发生，而对新生儿没有不良影响。

abstractsObjective To explore the anesthetic effect and neonatal effects of dexmedetomidine combined with ropivacaine in the cesarean section under epidural anesthesia .Methods Between January 2012 and March 2013 at the First Affiliated Hospital with Nanjing Medical University , sixty parturients with a single baby at full term in vertex presentation scheduled for caesarean section under epidural anesthesia , were randomly divided into 3 groups (n=20 each) according to the random digits table:dexmedetomidine +ropivacaine ( RD ) , fentanyl +ropivacaine ( RF ) and normal saline +ropivacaine ( RN ) . After identification of the epidural space and a negative aspiration test for blood or cerebrospinal fluid , 15 ml of 0.75% ropivacaine , was administered epidurally in three the groups with addition of 1 μg/kg of dexmedetomidine in RD group , 1 μg/kg of fentanyl in RF group and 2 ml of normal saline in RN group. Recording the mean arterial pressure ( MAP) and heat rate ( HR) before anesthesia ( T0 ) , at 10 min ( T1 )and 30 min (T2) after the end of epidural administration, and at end of operation (T3).Recording the onset time, maximum sensory analgesic level , time to maximum sensory analgesic level , time to two segmental dermatomal regressions , and time to chief complaint of postoperative pain .The modified bromage degrees , sedation scores and traction reaction were also assessed .The Apgar scores at 1 and 5 min were also recorded after delivery, and the blood samples were drawn from umbilical vein for gas analysis .Results MAP, HR and the motor block ( Bromage scale ) were no statistics differences among the three groups ( P>0.05 ) . Compared with RN group , the onset time and the time to maximum sensory analgesic level were significantly earlier [(6.3 ±2.4), (8.7 ±2.3) min vs(10.9 ±2.7) min; (11.5 ±3.9), (16.2 ±4.6) min vs (19.8 ±5.2) min ,P<0.05], the time to two segmental dermatomal regressions and the time to chief complaint of postoperative pain were prolonged significantly [(22.5 ±4.6), (18.5 ±3.9) min vs(13.5 ± 3.8)min;(415 ±92), (355 ±86) min vs( 273 ±68) min,P<0.05], level of sedation and degree of traction reaction were better in RD group and in RF group , and the incidence of shivering was lower in RD group (5% vs 40%, P<0.05), the incidence of dizziness was higher in RF group (20% vs 0, P <0.05).Compared with RF group, the same results were also seen about the onset time , the time to maximum sensory analgesic level , the time to two segmental dermatomal regressions and the time to chief complaint of postoperative pain , and the level of sedation was better , the incidence of drowsiness was lower in RD group.There were no statistics differences about both the blood gas analysis of umbilical vein and the Apgar scores at 1 and 5 min after delivery.Conclusion Administration of dexmedetomidine combined with ropivacaine can provide early onset , establishment of sensory anesthesia , much better sedation levels , decrease the degree of traction reaction and the incidence of shivering , and without adverse neonatal effects .