Application Of PCV-VG Ventilation Mode Of Contralateral Lung Combined With CPAP Of Affected Lung In Elderly Patients Undergoing Thoracoscopy Lobectomy

Objective:To investigate the effects of contralateral pressure control volume guarantee（PCV-VG）mode combined with continuous positive airway pressure（CPAP）on respiratory mechanics,hemodynamics,oxygenation,intrapulmonary shunt and pulmonary complications in elderly patients undergoing Thoracoscopy lobectomy.Methods:100 patients with 65-80 years who underwent elective thoracoscopic lobectomy were selected,with ARISCAT scores of 26 or above and ASA grades of Ⅱ-Ⅲ.Randomly divided eligible patients into four groups:PCV-VG group（P group）:during one lung ventilation,the surgical lung opens to the atmosphere,while the healthy side is given pressure-controlled ventilation-volume guaranteed（FiO₂ 60%,VT6ml/kg,f 15 times/min,I:E of 1:2,PEEP 5cm H₂O）.VCV group（V group）:during one lung ventilation,the surgical lung bronchial duct opens to the atmosphere,causing the lung to naturally collapse,The healthy side of the patient was given a volume controlled ventilation strategy（V_T 6ml/kg,f 15 times/min,PEEP 5cm H₂O）;PCV-VG combined with CPAP ventilation group in surgical side（PC group）:During one lung ventilation,the healthy side was given a PCV-VG ventilation strategy,with a pressure setting of 15-25cm H₂O（FiO₂ of 60%,VT6 ml/kg f 15 times/min,I:E of 1:2,PEEP of 5cm H₂O）,the surgical side was given CPAP（pressure setting of 5cm H₂O,FiO₂ of 100%,oxygen supply flow rate of 1L/min）,and the VCV group was combined with CPAP ventilation group（VC group）,25 patients in each group.Follow up the patient on admission（T0）,Checking the patient’s lungs with portable ultrasound and score according to LUS.After general anesthesia,patients were given tracheal intubation and mechanical ventilation.VCV ventilation mode（VT 8ml/kg,f12 times/min,PEEP 5cm H₂O）was used before one lung ventilation in all groups.One lung ventilation was given different ventilation modes according to different groups,and four groups of patients were recorded before anesthesia induction（T1）,10 minutes after anesthesia induction（T2）,change of posture（T3）,start of single lung ventilation（T4）,and 30 minutes after one lung ventilation（T5）Respiratory mechanics indicators such as peak airway pressure（Ppeak）,mean airway pressure（Pmean）,airway plateau pressure（Pplat）,dynamic lung compliance（Cdyn）,and recovery of bilateral lung ventilation for 60 minutes（T6）and 10 minutes（T7）.Blood gas analysis was performed in T4,T5,T6,radial artery blood and venous blood,and pH,PaO₂,PaCO₂,A-a DO₂,lactic acid and other index parameters were recorded.After the surgery,the patient was sent to PACU for extubation and deoxygenation observation.The patient was followed up after the surgery and the pulmonary complications such as respiratory infections were recorded within 7 days after the surgery.Result:（1）Respiratory mechanics indicators:Compared with Group V,Pmean,Ppeak,and Ppeak significantly decreased（P<0.05）and Cydn significantly increased（P<0.05）in the P and PC groups at T4-T6;Compared with Group C,Pmean,Ppeak,and Ppeak significantly decreased（P<0.05）and Cydn significantly increased（P<0.05）in Group PC at T4-T6,while there was no significant difference in Pmean,Ppeak,Ppeak,and Cydn Compared Group V in T4-T6（P>0.05）;Compared with the P group,there was no significant difference in Pmean,Ppeak,Ppeak,and Cydn between the PC group in T4-T6（P>0.05）;Compared with T2-T3,the Pmean,Ppeak,and Ppeak of the four groups significantly increased（P<0.05）and Cydn significantly decreased（P<0.05）at T4-T6;（2）Respiratory function indicators:Compared with the P group,the PC group showed a significant increase in PaO₂ and OI at T5-T6（P<0.05）,a significant decrease in QS/QT and lactate（P<0.05）,a significant decrease in PaO₂ and OI at T5-T6 in C and V groups（P<0.05）,and a significant increase in QS/QT and lactate（P<0.05）;Compared with Group C,PaO₂ and OI in PC group increased significantly（P<0.05）at T5-T6,while QS/QT and lactate decreased significantly（P<0.05）.PaO₂ and OI in V group decreased significantly（P<0.05）at T5-T6,while QS/QT and lactate increased significantly（P<0.05）;Compared with Group V,SPO₂ significantly increased at T5-T6 in PC group,P group,and C group（P<0.05）;Compared with T4,the PaO₂ value and oxygenation index（OI）of the four groups at T5 and T6 were significantly reduced（P<0.05）,while lactate and intrapulmonary shunt（QS/QT）were significantly increased（P<0.05）;（3）Hemodynamics:There was no significantly difference in MAP and HR between the four groups at T1-T7（P>0.05）;（4）Pulmonary ultrasound score:There was no significantly difference in LUS score between the four groups of patients before surgery（T0）（P>0.05）;Compare with Group C;The LUS score of PC group at T8 significantly decreased（P<0.05）,while there was no significant difference in LUS score of C group at T8（P>0.05）;Compared with Group V,the LUS scores of Group PC and Group P decreased significantly at T8（P<0.05）,while there was no significant difference in LUS scores of Group C at T8（P>0.05）;Compared with the P group,there was no significant difference in LUS score at T8 in the PC group（P>0.05）;（5）Postoperative complications:Compared with Group V,the incidence of PPCS within 7 days in Group PC and Group P was significantly reduced（P<0.05）,while there was no significant difference in the incidence of PPCS within 7 days in Group C（P>0.05）;Compared with Group C,the incidence of PPCS within 7 days in Group PC was significantly reduced（P<0.05）,while there was no significant difference in the incidence of PPCS within 7 days in Group V（P>0.05）;Compared with the P group,there was no significant difference in the incidence of PPCS within 7 days in the PC group（P>0.05）,while the incidence of PPCS within 7 days in the V group increased significantly（P<0.05）;Conclusion:During one lung ventilation,the healthy lung PCV-VG ventilation mode combined with CPAP in surgical side can effectively improve oxygenation and reduce intrapulmonary shunt in elderly patients undergoing thoracoscopic lobectomy;...