Effects Of Differential Lung Ventilation On Oxygenation And Respiratory Mechanics During Video-assisted Thoracoscopic Lobectomy In Middle-aged And Elderly Patients

Objective:Compare effects of differential lung ventilation（DLV）versus one lung ventilation（OLV）on oxygenation and respiratory mechanics during video-assisted thoracoscopic lobectomy（VATS）in middle-aged and elderly patients,compare the incidence of hypoxemia,assess whether DLV interferes with the surgical field,at the same time,the postoperative extubation time and the occurrence of postoperative pulmonary complications（PPCs）were compared between the two groups.Methods:Sixty patients undergoing elective video-assisted thoracoscopic lobectomy were randomly divided into single lung ventilation group（group O）and differential ventilation group（group D）,with 30 cases in each group.Five minutes before the operation,the O group was ventilated with one lung,the non-operative side of the D group was ventilated with the same way as that of the O group,while the operation side lung was connected to another ventilator for DLV.Before induction of general anesthesia（T0）,5 minutes before surgery（T1）,and 30 minutes after one-lung ventilation（T2）,the internal jμgular venous blood and radial artery blood of the two groups of patients were collected for blood gas analysis,and the PH,PaCO₂,and PaCO₂,HCO3^-,PaO2 values were recorded,and calculate oxygenation index（OI）and intrapulmonary shunt rate（QS/QT）based on blood gas results.Record the incidence of hypoxemia in the two groups,record the plateau airway pressure（Pplat）and peak airway pressure（Ppeak）at T1 and T2 and the surgeon’s assessment of surgical interference,evaluate the time of postoperative extubation and the occurrence of PPCs between the two groups.Results:The incidence of hypoxemia was greater in the D group than the O group（20%vs 0%）,the difference was statistically significant（P<0.05）.There was no significant difference between the two groups of PH,PaCO₂,HCO3^-at T0、T1and T2（P>0.05）.At T2,the PaO2 and OI of group D were significantly higher than those of group O（197.0 vs 101.0mm Hg,328.5 vs 168.8,respectively）,while QS/QT was lower than that of group O（21.6 vs 29.5,respectively）,the difference was statistically significant Significance（P<0.05）,the other time points were not statistically significant（P>0.05）.There was a statistically significant difference in Pplat（23.60vs 20.20cm H2O）and Ppeak（26.07 vs 23.57cm H2O）between group O and group D at T2（P<0.05）,and there was no significant difference at T1（P>0.05）.The postoperative extubation time in group O was longer than that in group D（68.0 vs61.3min）,the difference was statistically significant（P<0.05）.There was no significant difference between the two groups in the incidence of surgical interference and PPCs（P>0.05）.Conclusion:DLV can reduce the incidence of intraoperative hypoxemia,reduce airway pressure and QS/QT during one-lung ventilation,increase PaO2 and OI,and shorten postoperative extubation time,which can improve the oxygenation and respiratory mechanics of VATS in middle-aged and elderly patients and is better than the traditional one-lung ventilation mode,and does not increase the interference to the operation,however,it is not yet believed to reduce the incidence of PPCs.