A Randomized Comparison Of Efficiency Of Two Mechanical Ventilation Modes:Pressure Controlled Ventilation-volume Guarantee Versus Volume Controlled Ventilation In Adult Patients Undergoing Video-assisted Thoracoscopic Lobectomy

Objective:To compare the effects of pressure controlled-ventilation volume guarantee mode versus volume-controlled ventilation mode on efficacy,lung injury,and postoperative pulmonary complications during one lung ventilation（OLV）for adult video-assisted thoracoscopic lobectomy.Methods:A total of 45 patients to be elective video-assisted thoracoscopic unilateral lobectomy were included,23 in PCV-VG₁group and 22 in VCV₁groups.The mechanical ventilation mode of PCV-VG was implemented during OLV in the PCV-VG₁group,and the ventilator settings were as follows:Fi O₂80%,PEEP 5 mm Hg,I/E ratio 1:2,V_T6ml/kg,R 14 bmp,PETCO₂maintained at 40～55 mm Hg;The mechanical ventilation mode of VCV was implemented in the VCV₁group during OLV with the same ventilator settings.At the beginning of OLV（T₀）,30 minutes（T₁）,1 hour（T₂）,and at the end of OLV（T₃）to compare ventilation-related indicators(P_mean,P_peak,Pa O₂and Pa CO₂),hemodynamic indicators（HR and MAP）,serum inflammatory factors（IL-6,IL-1βand TNF-α）,and postoperative recovery indicators（the time of the postoperative drainage tube removal,postoperative hospitalization days and postoperative lung complications）.Eight patients,four each in the PCV-VG₂group and VCV₂group,were enrolled for elective video-assisted thoracoscopic bilateral lobectomy,and non-pathological specimens of the second resected lung tissue（which had received one lung ventilation in PCV-VG mode or VCV mode while contralateral lung tissue excision）were retained,thick sections were made and stained with hematoxylin/eosin（HE stained）,and the extent of lung tissue damage was observed under light microscopy.Results:There was no statistical difference between the PCV-VG group（PCV-VG₁group and PCV-VG₂group）and VCV group（VCV₁group and VCV₂group）in terms of age,BMI,gender,ASA classification,one lung side included in the study,and duration of surgery.The PCV-VG₁and VCV₁groups had no statistical differences in P_mean,Pa O₂,and Pa CO₂.Compared with the VCV₁group,the P_peakvalues in the PCV-VG₁group were significantly lower and greatly statistically significant（P=0.002）.There was no statistical difference in the MAP and HR results between the PCV-VG₁and VCV₁groups at T₁,T₂,and T₃time points compared with T₀.There was no statistical difference in the time of postoperative drainage tube removal and postoperative hospitalization days.Compared with the VCV₁group,there was no statistical difference in the PCV-VG₁group based on the change in IL-6 and IL-1βvalues at T₁,T₂,and T₃based on T₀.Compared with the VCV₁group,there was no statistical difference in the change of values of TNF-αat T₁and T₂based on T₀in the PCV-VG₁group,and the change of values of TNF-αat T₃in the PCV-VG₁group were smaller and greatly statistically different（P=0.002）.The results of HE staining of lung tissues in the PCV-VG₂and VCV₂groups showed relatively severe structural damage,alveolar hemorrhage and inflammatory cell infiltration in the VCV₂group,and the lung tissue damage score was smaller in the PCV-VG₂group,but not statistically different.Conclusion:Compared with the ventilation mode of VCV,the PCV-VG mode provides lower peak airway pressure,releases less TNF-αinflammatory factors,and has a lower degree of HE staining damage in lung tissue sections.