定压和定容通气模式对单肺通气气道压力和动脉血气的影响

Effect of pressure controlled ventilation and volume controlled ventilation on the airway pressure and arterial blood gas during one lung ventilation

目的观察压力控制通气(PCV)和容量控制通气(VCV)模式对胸科手术单肺通气(OLV)时气道压力和动脉血气的影响。方法 40例肺功能正常的开胸手术患者随机均分为两组,均先给予双肺通气(TLV)VCV模式,后在OLV时均加用呼气末正压通气(5cmH_2O),A组先采用OLV-VCV模式,30min后转换为OLV-PCV模式;B组先采用OLV-PCV模式,30min后转换为OLV-VCV模式。分别在每种通气模式结束后行动脉血气分析,记录气道压力、动脉血二氧化碳分压(PaCO_2)、动脉血氧饱和度(SaO_2)和动脉血氧分压(PaO_2),计算肺内分流率(Qs/Qt)。结果与TLV-VCV相比,OLV-VCV或OLV-PCV模式下PaO_2下降,Qs/Qt、气道峰压(P_(peak))和平均气道压(P_(mean))升高(P<0.05)。与OLV-VCV模式相比,OLV-PCV模式下P_(peak)和P_(mean)降低(P<0.05),两种OLV通气模式下PaO_2和Qs/Qt无统计学差异(P>0.05)。三种通气模式下PaCO_2、SaO_2均无统计学差异(P>0.05)。结论开胸手术患者在小潮气量OLV期间,与VCV模式相比,PCV模式不能提高氧合作用,但气道压力低,有利于减轻气道损伤。

Objective To investigate the effect of pressure controlled ventilation （PCV ） and volume controlled ventilation （VCV ） on the airway pressure and arterial blood gas during one lung ventilation（OLV） .Methods Forty patients with good preoperative pulmonary function scheduled for thoracic surgery were randomly and equally divided into two groups .Both groups started with VCV during two lungs ventilation（TLV‐VCV） .Twenty patients in group A underwent OLV initially with VCV for 30 minutes followed by PCV for a similar duration ,and the other 20 patients in group B underwent OIV initially with PCV for 30 minutes followed by VCV for a similar duration .Airway pressure and arterial blood gas were obtained during OLV at the end of each ventilation mode . Intrapulmonary shunt （Qs/Qt） was calculated and artery partial pressure of oxygenation （PaO2 ） , artery partial pressure of carbon dioxid （PaCO2 ） and artery oxygen saturation （SaO2 ） were recorded . Results Compared with TLV‐VCV ,PaO2 was descended and Qs/Qt ,peak airway pressure（Ppeak ） and mean airway pressure（Pmean） were ascended by OIV‐VCV and OIV‐PCV（P〈0 .05） .Compared with OLV‐VCV ,Ppeak and Pmean were descended by OIV‐PCV （ P〈0 .05 ） .There were no significant differences in PaO2 and Qs/Qt between OLV‐VCV and OIV‐PCV（P〉0 .05） .PaCO2 and SaO2 showed no significant differences among the three ventilatory modes （P〉0 .05） .Conclusion Compared with VCV ,PCV is not able to improve oxygenation ,but can decrease lower airway pressure and reduce airway injury in thoracic surgery during OLV with low tidal volume .