Lung Protection In Patients With One-lung Ventilation Surgery After Combinating One Lung Hypoxic Preconditioning And Improved Lung Recruitment

BackgroundOne-lung ventilation(OLV)refers to a method in which only one side of the lung(non-surgical side)is used for ventilation.The main pLurpose is to achieve lung isolation and provide a good vision for the operation,is essential for most thoracic surgeries,with the growing variety and surgical style of thoracic surgery,one-lung ventilation technology is also facing increasing challenges.One-lung ventilation is prone to hypoxemia and lung injury during perioperative period,affecting the prognosis of patients.We can take a variety of methods to correct hypoxemia,but there are still some patients may have refractory hypoxemia.In addition,one-lung ventilation inevitably causes various lung injuries,and induces a large number of inflammatory factors such as interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-a),and it will continue to increase lung damage.At present,there is no standardized lung protection procedure for preventing hypoxemia and lung injury during one-lung ventilation.In the previous study,our team found that during the one-lung ventilation surgery,taking one lung hypoxic preconditioning or improved lung recruitment can achieve lung protection,mainly in the prevention of hypoxemia,reduce lung damage,reduce the expression of inflammatory factors,improve perioperative oxygenation in patients.ObjectiveTo observe whether the combination of one lung hypoxic preconditioning and improved lung recruitment can achieve superimposed lung protection in one-lung ventilation surgery.Methods120 adult patients scheduled for left or right OLV thoracic surgery were randomly divided iinto 4 groups:Group A,GroupB,Group A+B,or Group C(n=30 each).Anesthesia was induced and maintained with propofol target-controlled infusion,and mechanical ventilation was performed after inserting a double-lumen bronchial tube(DLT).’To make a hypoxic preconditioning in Group A.When the towel was started,the DLT non-ventilated side Y-joint was clamped three times,then made the DLT tracheal cavity was connected to the atmosphere to OLV for 1 min each time,and the two-lung ventilation(TLV)was restored for 1 min each time.To make an improved lung recruitment in group B.In Group B,5 cycles of mechanical ventilation with a VT 10ml/kg and RR 12 bpm were performed before manual reinflation.To take both hypoxic preconditioning and improved lung recruitment in Group A+B.Group C,as the control group.The hemodynamics,oxygenation index and inflammatory factors such as IL-6,TNF-a,etc.were recorded before surgery,before and after preconditioning,after OLV 20 minutes,before and after reinflation,after TLV 20 minutes,30 minutes after extubation,6 hours after surgery,and one day after surgery.Results1.General comparison:Preoperative basic conditions,pulmonary function tests,anesthesia time,and OLV time were not statistically significant(P>0.05).The postoperative hospital stay in group C was greater than the other three groups(P<0.01),there was no significant difference between the A+B group and the other two groups(P>0.05).2.Oxygenation index comparison:①The oxygenation index of patients in group A and group A+B was higher than that in group C and group B(P<0.01);②After surgery,group C had the lowest OI,while group A+B had higher OI than group A and group B.(P<0.05).3.Comparison of inflammatory factors:①The IL-6 levels of the four groups were increased first and then decreased.The IL-6 of the C group was higher than the other three groups(P<0.01),and the lowest in the A+B group(P<0.01).There was no significant difference in the comparison between group A and group B(P>0.05).②One day after operation,TNF-a was higher in group C than in the other three groups,and lowest in group A+B(P<0.05).There was no significant difference between the other two groups(P>0.05).4.Comparison of circulatory and pro BNP:group B and A+B were more stable.After surgery,the proBNP in group C and group A were higher than that in group B and A+B(P<0.01).Conclusion1.One lung hypoxic preconditioning can maintain better oxygenation during the OLV;Improved lung recruitment can maintain a more stable hemodynamics;Both can reduce the level of postoperative inflammatory factors and improve oxygenation.2.Combined one lung hypoxic preconditioning and improved lung recruitment can improve the perioperative oxygenation and reduce IL-6 and TNF-a levels,reduce postoperative pulmonary complications,and have a superimposed effect on lung protection.