The individual lung protective ventilatory parameters setting guided by pressure-volume curve in patients undergoing one-lung ventilation during thoracic surgery

Objective To investigate the optimal individual tidal volume and positive end-expiratory pressure(PEEP)based on the dynamic pressure-volume curve for patients with one-lung ventilation.Methods Forty-two ASAⅠ～Ⅱ patients scheduled for an elective lobectomy were randomly enrolled in this study.The conventional two lung ventilation was kept for 30 min(T0)and followed by one-lung ventilation(OLV)operation.PEEP was applied to the lung ventilation by PLIP + 0.196 kPa of P-V curve,three different tidal volume modes were conducted successively,T1(100% VUIP),T2(80% VUIP)and T3(60% VUIP),each mode was kept for 30 min.Value of tidal volume,MAP,HR,CVP,peak airway pressure(Ppeak),airway resistance(Raw)and lung-thorax compliance(CT)were recorded,and the blood gas and pulmonary shunt fraction(Qs/Qt)were calculated.Results PEEP was(0.64 ± 0.13)kPa and tidal volume was(10.1 ± 1.2)mL/kg,(7.2 ± 1.1)mL/kg,(5.6 ± 0.7)mL/kg at T1,T2 and T3.Compared with T1,the Ppeak,Raw and Qs/Qt reduced,PaO2 and CT got corresponding improvement at T2,MAP,and PaCO2 increased at T3 significantly(P 0.05).Conclusion In terms of dynamic P-V curve,80% VUIP adding PLIP + 0.196 kPa PEEP can improve arterial oxygenation and pulmonary compliance,and decrease pulmonary shunt fraction during OLV,however,the effect of haemodynamics is not significant.