Effects Of Lung Protective Ventilation Strategy Based On Press-volume Curve On Patients During One-Long Ventilation Anesthesia

Objective: To investigate the effects of lung protective ventilation strategy based on Press-volume Curve setting PEEP on respiratory mechanics, gas exchange function and interleukin (IL)-6,tumor necrosis factor-α(TNF-α) in patients undergoing lung resection during one-lung ventilation.Methods:120 ASA classⅠorⅡpatients with MVV(measured/predicted value)>70%, FEV1(measured/predicted value)>60% scheduled to undergo lung resection were randomly divided into group C (Vt=10ml/kg, PEEP=0), group P-2 (PEEP=Pinf-2cmH2O, Pinf as identified on the P-V curve, is the lowest point on the curve that defines an area of maximum compliance change ,Vt=6ml/kg), group P+0 (PEEP=Pinf+0cmH2O,Vt=6ml/kg), and group P+2 (PEEP=Pinf+2cmH2O,Vt=6ml/kg), group P0 (PEEP=0, Vt=6ml/kg) , n=24 in each group. Pplat, Ppeak, Raw and Cdyn were recorded every five minutes after TLV and OLV. The arterial blood gas samples were drawn before operation (BO), immediately 20 minutes after two-lung ventilation (TLV) and one-lung ventilation (OLV) after anesthesia. Beginning of OLV (T1), end of OLV(T2), the venous blood samples were taken for detecting IL-6, TNF-α.Results: Cdyn decreased, Pplat, Ppeak, Raw increased significantly during OLV compared with those during TLV in all groups. During TLV and OLV, Raw decreased in group P+2 compared with those in group C. In all groups , compared with BO, Qs/Qt, PaO2 increased during OLV and TLV, PaO2 is highest during TLV, compared with TLV, Qs/Qt is higher during OLV. Compared with group C, PaCO2 increased in other groups at OLV and TLV, but it is in normal levels in clinic. Concentrations of IL-6 in all groups were increased significantly at T2 compared with those at T1, but much lower in group P+2 than those in others at T2. The percentages of TNF-αnot being detected were 61%,54%,56%,63%,59% at T1 and 52%,54%,56%,63%,59% at T2 in group C, group P-2, group P+0, group P+2 and group P0.Conclusion: During OLV for lung resection, protective ventilation (low Vt and PEEP= Pinf+2cmH2O) can reduce Raw in patients with lung function decreased slightly or normal, but it has no effects on oxygenation or compliance in short time, decrease the release of IL-6 and inhibit inflammatory responses.