中文摘要：

目的观察右美托咪定对急性呼吸窘迫综合征（ARDS）机械通气患者镇静镇痛效果及呼吸和血流动力学的影响。方法将70例需镇静镇痛的ARDS机械通气患者按照随机原则分为右美托咪定组（D组，35例）和咪达唑仑组（M组，35例）。用微量泵静脉注射给药，D组给予右美托咪定负荷量1μg／kg，10min后继以0．2～0．7μg·kg^-1·h^-1维持；M组给予咪达唑仑负荷量0．06mg／kg后以0．04-0．20mg·kg^-1·h^-1维持。比较两组患者疼痛评分、唤醒时间、机械通气时间、顺行性遗忘以及心率（HR）、收缩压（SBP）、舒张压（DBP）、呼吸频率（RR）和动脉血氧饱和度（SaO：）的变化。结果两组患者性别、年龄及急性生理学与慢性健康状况评分系统Ⅱ（APACHEII）评分比较差异均无统计学意义（均P〉0．05），有可比性。Ramsay评分在2-4分时，D组视觉模拟评分（VAS，分）明显低于M组（2．68±0．47比5．87±0．62，P〈0．01），唤醒时间（h）明显短于M组（0．18±0．04比1．78±0．62。P〈0．01），顺行性遗忘例数明显少于M组（8比33，P〈0．01）；而D组和M组机械通气时间（d）相似（3．65±1．73比3．76±1.61，P〉0．05）。两组用药30min后HR、SBP、DBP,RR均较用药前下降，其中D组HR、SBP、DBP、RR较M组下降明显[HR，次／min：69．4±7．5比80．6±9．3；SBP，mmHg（1mmHg=0．133kPa）：90．8±4．8比98．2±4．3；DBP,mmHg：51．4±6．8比60．2±7．6；RR，次／min：20．5±4．1比22．6±3．2，均P〈0．05）；两组SaO3下降不明显（P〉0．05）。结论右美托咪定是ARDS机械通气患者较理想的镇静镇痛药物。

英文摘要：

Objective To investigate the effects of sedation and analgesia and the influence on respiratory and hemodynamies of dexmedetomidine in treatment of mechanically ventilated patients with acute respiratory distress syndrome （ARDS）. Methods Seventy mechanically ventilated patients with ARDS necessary to take sedative and analgesic drugs were randomly divided into dexmedetomidine group （D group, 35 cases ）and midazolam group （ M group, 35 cases ）. The drugs in both groups were administered by micro pump intravenous injection, the patients in D group were given a loading dose （1 μg/kg ）for 10 minutes and then maintained with 0.2-0.7 μg·kg^-1·h^-1 and the patients in M group were given a loading dose （0.06 mg/kg ）and then maintained with 0.04-0.20 mg·μg·kg^-1·h^-1. Pain symptom, awakening time, length of mechanical ventilation, incidence of anterograde amnesia, and changes in heart rate （HR）, systolic press （SBP）, diastolic press （DBP）, respiratory rate （RR） and arterial oxygen saturation （SaO2 ） were compared between two groups. Results There was no significant difference in gender proportion, age and acute physiology and chronic health evaluation 11 （APACHE ]] ）score between the two groups （all P〉0.05 ）. When the intake dose was adjusted to maintain Ramsay score of 2-4, the score of visual analogue scale （VAS）in D group was obviously lower than that in M group （2.68 ± 0.47 vs. 5.87 ± 0.62, P〈 0.01 ）, the awakening time （hour）was significantly shorter than that in D group （0.18 ± 0.04 vs. 1.78 ± 0.62, P〈 0.01 ）, the case of anterograde amnesia was markedly less in D group than that in M group （8 vs. 33, P〈 0.01 ）, but there was no significant difference in the length （day） of mechanical ventilation （3.65 ± 1.73 vs. 3.76 ± 1.61, P〉O.05 ）. Compared with those before the treatment, the levels of HR, SBP, DBP, RR were remarkably decreased after treatment for 30 minutes in the two groups, in which HR, SBP, DBP and RR were si