右旋美托咪啶复合异氟烷对单肺通气肺内分流及动脉氧合的影响

目的:观察右旋美托咪啶(Dex)持续静脉输注复合异氟醚(ISO)吸入用于单肺通气,肺内分流、动脉氧合以及血流动力学变化。方法:60例美国麻醉医师协会分级(ASA)Ⅰ～Ⅱ级择期开胸手术患者,随机分为静脉输注Dex复合ISO吸入组(DISO组)与静脉输注生理盐水复合ISO吸入组(NISO组)。2组患者麻醉诱导药物一致,麻醉维持均静脉持续输注瑞芬太尼0.1～0.2μg.kg-1.min-1,吸入ISO 1.0%～2.0%。DISO组持续静脉输注Dex 0.7μg.kg-1.h-1,NISO组持续静脉输注等容量0.9%氯化钠液。持续观察心率(HR)、平均动脉血压(MAP)、脉搏氧饱和度(SpO2),脑电双频指数(BIS),分别于单肺肺通气前、单肺通气10 min(OLV-10 min)、20 min(OLV-20 min)、30 min(OLV-30 min)、40 min(OLV-40 min)监测动脉血气、中心静脉血气及呼气末ISO浓度(EEIso)。通过BIS调整ISO吸入浓度。结果:45例患者完成研究,DISO组23例,NISO组22例;2组患者单肺通气时动脉氧分压、分流量与单肺通气前比较,PaO2明显下降(P<0.05),Qs/QT明显增加(P<0.05);单肺通气期间,与NISO组比较,DI-SO组PaO2明显增加(P<0.05),Qs/QT明显减少(P<0.05);DISO组EEIso明显减少(P<0.05),心率明显减少(P<0.05),平均动脉血压以及血管活性药物的使用比较,差异无统计学意义(P>0.05)。结论:静脉输注Dex复合ISO吸入用于单肺通气,能够降低动脉血氧分压下降程度、减少肺内分流及减少ISO需要的剂量。

Effects of intravenous infusion dexmedetomidine combined with isoflurane inhalation on arterial oxygenation and intrapulmonary shunt during one-lung ventilation

Objective:To investigate the changes of intravenous infusion dexmedetomidine combined with isoflurane inhalation on arterial oxygenation,intrapulmonary shunt and haemodynamics during one-lung ventilation(OLV).Methods:Sixty patients aged 18-70 yr,ASA Ⅰ~Ⅱ,undergoing OLV during elective thoracic surgery were randomly allocated to two groups: isoflurane +saline(group NISO,n=30) and isoflurane+dexmedetomidine(group DISO,n=30).The anesthetics of induction were same for two groups,and the anaesthesia was maintained with intravenous infusion of remifentanil 0.1~0.2 μg·kg-1·min-1 and inhalation isoflurane(1.0%~2.0%).In addition,intravenous infusion of dexmedetomidine 0.7 μg·kg-1·h-1 was used for group DISO,and same volume saline for group NISO.Bispectral Index values were maintained within 40~60 by adjusting the concentration of isoflurane for two groups.Arterial blood gas samples,central venous blood gas samples and the concentration of end expiration isoflurane were taken as follows: before OLV,at the 10 min,20 min,30 min and 40 min after OLV respectively.Results: 45 patients completed the study,23 patients in group DISO and 22 patients in group NISO.The PaO2 was significant decreased and Qs/QT was significant increased at every time points during OLV in two groups compared with two-lung ventilation(P<0.05).During OLV,the PaO2 was significant increases,the Qs/QT and concentration of end expiration isoflurane were significant decrease compared with patients in the group NISO.and the HR in the group DISO was significant decrease either.There were no significant difference with haemodynamics and vascular active drugs in two groups(P>0.05)during the first 40 min of OLV compared with(P<0.05).Conclusion: Intravenous infusion dexmedetomidine combined with isoflurane inhalation during OLV can improve the PaO2,decrease intrapulmonary shunt and requirement of isoflurane.