摘要目的 研究右美托咪定(dexmedetomidine,DEX)和盐酸吗啡对慢性阻塞性肺病急性发作期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)行机械通气患者呼吸力学的影响. 方法 入选AECOPD伴呼吸衰竭行机械通气患者40例;在同样的分钟通气量和呼气末正压的设置下,采用随机对照的方法分为两组(对照组、试验组),每组20例,对照组使用吗啡进行镇静治疗,实验组使用盐酸DEX.记录两组患者急性生理功能和慢性健康状况评分系统Ⅱ(acute physiology and chronic health evaluation,APACHEⅡ)评分、脑电双频指数(bispectral index,BIS)评分、Ramsay镇静评分等指标.比较两组患者镇静前后生命体征、血气的变化和镇静后呼吸力学参数的变化. 结果 与对照组比较,实验组中平均动脉压(mean arterial pressure,MAP)和脉搏[(80±3) mm Hg比(75±4) mm Hg(1 mm Hg=0.133 kPa)和(90±3)次/min比(79±3)次/min]降低(P＜0.01),平均气道压(mean airway pressure,Paw)、平台压(plateau pressure,Pplat)[(7.5±0.7)cm H2O比(6.2±0.6)cm H2O (1 cm H2O=0.098 kPa)、(19.8±1.7) cm H2O比(18.0±l.1) cm H2O]明显降低(P＜0.01),峰食道压力(peak esophageal pressure,PPEAKES)、PFEAK ES与基准食道压力差(the peak esophageal manometry reference esophagus pressure difference,dPES)[(-3.4±0.7)cm H2O比(-5.4±1.0)cm H2O、(-6.9±1.0)cm H2O比(-9.8±1.3)cm H2O]变大(P＜0.01),吸气末屏气期间的跨肺压(folding screen the end of the suction gas during transpulmonary pressure,Ptp Plat)、肺静态顺应性(pulmonary static compliance,Cst)[(25.5±2.3) em H2O比(26.0±2.6) cm H2O、(20.5±1.9) cm H2O比(20.1±1.2)cm H2O]变化无统计学意义(P＞0.05),气道阻力(airway resistance,Raw)[(20.3±09)cmH2O·L4·s-2比(15.6±1.4) cm H2O·L-1 ·s-1]变小(P＜0.01),患者呼吸功(patient work of breathing,WOBp)[(0.11±0.02)j/L 比(0.16±0.04) j/L]明显增加(P＜0.01),机械呼吸功(mechanical work of breathing,WOBv)[(0.49±0.10) j/L比(0.43±0.06)j/L]明显降低(P＜0.05).机械通气时间、重症监护室(ICU)入住时间[(76±5)h比(64±3)h、(6.0±1.5)d比(4.6±0.9)d]减少(P＜0.05).结论 与吗啡比较,DEX能提高机械通气患者的镇静效果、降低Raw、提高肺顺应性,有利于实施保护性通气策略,同时降低呼吸负荷和呼吸做功,因而能降低呼吸氧耗.

abstractsObjective To study the effect of dexmedetomidine(DEX) and morphine hydrochloride on respiratory mechanics in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) undergoing mechanical ventilation.Methods Forty patients of AECOPD with respiratory failure undergoing mechanically ventilated were randomly divided into two groups (n=20).The control group were treated with morphine for sedation while the experimental group with DEX.APACHE Ⅱ score,bispectral index (BIS) score,ramsay score were recorded.Respiratory mechanical parameters after sedation,and changes in vital signs as well as blood gas were compared before and after sedation.Results Compared with the control group,the mean arterial pressure (MAP) and pulse in the experimental group were decreased after sedation[(80±3) mm Hg vs (75±4) mm Hg(1 mm Hg=0.133 kPa),(90±3) bpm vs (79±3) bpm](P＜0.01).The mean airway pressure(Paw) and plateau pressure(Pplat) were significantly downregulated in experimental group [(7.5±0.7) cm H2O vs (6.2±0.6) cm H2O (1 cm H2O=0.098 kPa),(19.8±1.7) cm H2O vs (18.0±1.1) cm H2O] (P＜0.05).peak esophageal pressure (PPEAK ES) and the peak esophageal manometry reference esophagus pressure difference (dPES) was increased [(-3.4±0.7) cm H2O vs (-5.4±1.0) cm H2O,(-6.9±1.0) cm H2O vs (-9.8±1.3) cm H2O] (P＜0.01).There were no significant difference between the two groups in folding screen the end of the suction gas during transpulmonary pressure (Ptp Plat) and pulmonary static compliance (Cst)[(25.5±2.3) cm H2O vs (26.0±2.6) cm H2O,(20.5±1.9)em H2O vs (20.1±1.2) cm H2O].The airway resistance (Raw)[(20.3±0.9) cm H2O·L-1·s-1 vs (15.6±1.4) cm H2O·L1·s-1](P＜0.01)and mechanical work of breathing (WOBv)[(0.49±0.10) j/L vs (0.43±0.06) j/L](P＜0.05) were increased.The patient work of breathing (WOBp) was significantly increased [(0.11 ±0.02)j/L vs (0.16±0.04)j/L] (P＜0.01).The time of mechanical ventilation and the intensive care unit (ICU)staying time were reduced [(76±5) h vs (64±3) h、(6.0±1.5) d vs (4.6±0.9) d](P＜0.05).Conclusions DEX increased the sedative effect and lung compliance,and decreased Raw in patients undergoing mechanical ventilation compared with morphine.DEX would also unload respiratory muscle oxygen consumption estimated by reducing the inspiratory load and work of breathing.