Effects Of Different Ventilation Strategies On Oxygenation And Inflammatory Factors In Patients Undergoing One-Lung Ventilation

Research BackgroundEsophagus,connected from the pharynx to the stomach from the cardia,is an important muscle organ of the digestive tract.A variety of inductive factors can cause malignant changes in epithelial tissues,leading to different degrees of eating difficulties.It is a common gastrointestinal tumor with high malignancy.In the past60 years,intrathoracic surgery is still the main treatment of esophageal cancer.However,such surgery has certain technical requirements on lung ventilation,pollution barrier and exposure of operating field.One-lung ventilation（OLV）with its special ventilation mode provides good advantages for operation and is widely used in chest surgery.At the same time,ventilator induced lung injury（VILI）has always been the most important concern of lung injury during anesthesia.OLV not only provides advantages for surgery,but also affects the changes of respiratory physiology,intraoperative posture,gravity and operation during operation,which can lead to complications such as imbalance of ventilatory blood flow ratio,inflammatory stress response,atelectasis and so on.In order to alleviate lung trauma,lung protective ventilation strategy has become a necessary consensus measure.VILI is a complex caused by many factors.The strategic operation is mainly applied in three aspects:small tidal volume（VT）,appropriate end-expiratory positive pressure（PEEP）,and intermittent alveolar recruitment（RM）.However,in clinical practice,both too large or too small VT and PEEP will affect oxygenation and even change hemodynamics.RM can avoid atelectasis as much as possible and also affect the mechanical stress of alveoli,so the setting of each parameter needs further experimental study.PEEP can maintain alveolar dilatation and reduce alveolar shear force during mechanical ventilation.In recent years,the setting of PEEP value has attracted much attention.Open lung strategy（OLS）is the individualized PEEP strategy set after alveolar reopening combined with low tidal volume.Studies have shown that it can improve the pulmonary compliance and oxygenation indexes of ARDS patients,which is of great significance for the protection of lung function of patients.PurposeTo investigate the effects of lung open strategy on oxygenation and inflammatory factors in patients undergoing radical resection of esophageal cancer by reducing PEEP titration and fixed PEEP value.MethodSixty patients with elective radical thoracoesophageal carcinoma were selected as the research subjects,regardless of gender,age 45-75 years old,BMI 18.5-24kg/㎡,ASA I-II.Patients were randomly divided into two groups according to random number table method,PEEP titration group:experimental group（n=30,group M）,PEEP titration group:control group（n=30,group C）.The initial PEEP value of both groups was 5cm H₂O（1cm H₂O=0.098 k Pa）during OLV.OLS was performed in the experimental group after hemodynamical stability.Optimal compliance with end-expiratory positive pressure（OL-PEEP）was detected and applied until the end of the operation.Respirational mechanics indexes of both groups were recorded after intubation（T₁）,OLV immediately（T₂）,30min after OLS application（T₃）,and 60min after OLS application（T₄）.Airway platform pressure（Pplat）,peak airway pressure（Ppeak）,and pulmonary compliance（Cdyn）were recorded.The arterial blood was extracted at each time point for blood gas analysis,and the partial pressure of oxygen（PaO₂）and partial pressure of carbon dioxide（PaCO₂）were recorded to calculate the oxygenation index（OI）.The levels of interleukin-6（IL-6）,interleukin-8（IL-8）and Clara cell secretory protein（CC16）in venous blood were detected before（T₀）,after（T₅）and 24h after（T₆）.In addition,postoperative pulmonary complications（such as hypoxemia,atelectasis,nausea and vomiting,infection,arrhythmia,etc.）were recorded in both groups.All data in this study were analyzed by SPSS21.0 statistical software.Results1.There were no significant differences between the two groups in general conditions（P>0.05）.2.There was no significant difference in OLV time and operation time between the two groups（P>0.05）.3.Blood gas index（1）PaCO₂:PaCO₂ of patients in the two groups were tested by Mauchly sphericity test,which was based on the results of intra-body effect test.There was no interaction between time and group,and there was no significant difference in PaCO₂between the two groups from T₁～T₄（P>0.05）.（2）OI:The OI of patients in the two groups was tested by Mauchly sphericity test,which was subject to the result of intra-body effect test.OI in group M increased significantly at T₃～T₄（P<0.05）.There was interaction between group and time,OI in group M increased significantly at T₃～T₄（P<0.05）.4.Respiratory mechanics indexes（1）Pplat:Pplat of two groups of patients passed Mauchly sphericity test,which was subject to the result of intra-body effect test.Pplat of M group increased significantly at T₃～T₄（P<0.05）.There was interaction between group and time,Pplat in group M increased significantly at T₃～T₄（P<0.05）.（2）Ppeak:Ppeak of the two groups was corrected by Greenhouse-Geisser,which was subject to multivariate test analysis.Ppeak value of the two groups increased significantly at T₃～T₄（P<0.05）.There was interaction between group and time,Ppeak in group M increased significantly at T₃～T₄（P<0.05）.（3）Cdyn:Cdyn of patients in the two groups were tested by Mauchly sphericity test,which was subject to the results of intra-body effect test.Cdyn increased significantly at T₃～T₄ in the two groups（P<0.05）.There was interaction between group and time,Cdyn in group M increased significantly at T₃～T₄（P<0.05）.5.Inflammatory factors（1）IL-6:The value of IL-6 in the two groups was corrected by Greenhouse-Geisser,which was subject to multivariate test analysis.Compared with T₀,IL-6 in both groups increased significantly at T₅～T₆（P<0.05）,and decreased significantly at T₆ compared with T₅（P<0.05）.There was an interaction between time and group,and IL-6 decreased significantly at T₅～T₆ in M group（P<0.05）.（2）IL-8:The value of IL-8 in two groups was tested by Mauchly sphericity test,which was based on the result of intra-body effect test.Compared with T₀,IL-8 in two groups increased significantly at T₅～T₆（P<0.05）,and decreased significantly at T₆compared with T₅（P<0.05）.The overall effect of time and group was notsignificant,IL-8 in group M decreased significantly at T₅～T₆（P<0.05）.（3）CC16:CC16 values of patients in the two groups were tested by Mauchly spherical degree,and the results of intra-subject effect test were taken as the criterion.Compared with T₀,CC16 values in the two groups were significantly increased at T₅～T₆（P<0.05）,and significantly decreased at T₆ compared with T₅（P<0.05）.There were interaction effects between group and time,and CC16 was significantly decreased in group M at T₅～T₆（P<0.05）.6.There was no statistical difference in postoperative complications between the two groups（P>0.05）.ConclusionIn patients undergoing radical esophagectomy under general anesthesia,one-lung ventilation will lead to decreased lung compliance,oxygenation and increased systemic inflammatory factors.The protective ventilation strategy of using lung open strategy to titrate individualized PEEP can significantly increase lung compliance,improve oxygenation and reduce the production of inflammatory factors,which is conducive to lung protection.