定压和定容两种模式在老年单肺通气麻醉中的应用

目的观察在单肺通气（one-lung ventilation,OLV）期间定压和定容两种通气模式应用于老年胸科手术时,对呼吸力学、血流动力学、肺呼吸生理学的影响。方法选择36例老年胸科手术患者,ASAⅡ~Ⅲ级,随机分为观察组和对照组各18例,全凭静脉快速麻醉诱导下双腔气管导管插管,先行双肺定容通气模式,潮气量为10 ml/kg,呼吸频率为12次/min,进胸后行单肺通气。观察组采用定压模式,压力限定设为双肺通气时的气道峰压值,呼吸频率为14次/min;对照组采用定容模式,潮气量为10 ml/kg,呼吸频率为14次/min。麻醉机监测气道峰压（Ppeak）、气道平均压（Pmean）、分钟通气量（MV）,监测心电图（ECG）、动脉血压（BP）、血氧饱和度（SpO2）和呼气末二氧化碳分压（PETCO2）。术前和术后分别抽取动脉血做血气分析,记录动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）,并根据Fick公式计算出肺泡-动脉血氧分压差（PA-aDO2）。结果观察组和对照组比较,Ppeak、Pmean均下降,术后PaO2升高,△PA-aDO2减小（P〈0.01）。结论老年单肺通气采用定压通气模式有利于肺泡氧合,降低单肺通气对呼吸力学影响和肺生理功能的损伤。

Effect of pressure controlled ventilation versus volume controlled ventilation during one-lung ventilation in elderly patients

Objective To investigate the effect of two different ventilation modes of one-lung ventilation（OLV） with pressure controlled ventilation（PCV） or volume controlled ventilation（VCV） in thoracic surgeries on respiratory mechanics,hemodynamics and pulmonary respiratory physiology in the aged.Methods 36 elderly patients with ASA Ⅱ-Ⅲ undergoing thoracic surgeries were randomly divided into control group and experimental group with 18 patients each.Under rapid total intravenous anesthesia,double-lumen endotracheal tubes（DLT） were intubated.First two-lung volume controlled ventilation（TLV-VCV） was selected with the tidal volume（VT） of 10 ml/mg,at a respiratory frequency（f） of 12 breaths per minute（bpm）.When the pleural cavity was opened,ventilation mode was shifted to OLV.The experimental group was set to mode of OLV-PCV,with the pressure limit as Ppeak in TLV at a rate of 14 bpm,and the control group was set to OLV-VCV,with a Vt of 10 ml/mg and a frequency of 14 bpm accordingly.The values of Ppeak,Pmean and MV were measured by Taema anesthesia machine.Meanwhile ECG,iBP,SpO2 and PETCO2,were also monitored.Besides,PaO2 and PaCO2 by blood gas analyzers were recorded before and after the surgery,and PA-aDO2 was calculated according to Fick formula.Results Compared with the control group,Ppeak and Pmean decreased（P0.01）,PaO2 significantly increased（P0.01） and PA-aDO2 diminished（P0.01） in the experimental group.Conclusion The ventilation mode of OLV-PCV in elderly patients facilitates the oxygenation of alveoli and attenuates the effect of OLV on respiratory mechanics and injuries to the physiological functions of the lungs.