Efficacy Of PCV-VG Mode For Lung Protective Ventilation In Patients Requiring One-lung Ventilation Undergoing Thoracoscopic Surgery

Objective To evaluate the efficacy of pressure-controlled volume-guaranteed?PCV-VG?mode for lung protective ventilation in patients requiring one-lung ventilation?OLV?during thoracoscopic surgery.Methods Sixty patients,aged 50⁷0 years old,with body mass index of 18²6 kg/m²,of American Society of Anesthesiologists physical status I or II,scheduled for elective radical resection of esophageal cancer performed via video-assisted thoracoscopic under general anesthesia,they were divided into 2 groups while volume-controlled ventilation group?group V?and pressure-controlled volume-guaranteed group?group P?.The ventilator settings were adjusted,with a tidal volume 10 ml/kg and respiratory rate 10-12 breathes/min during two-lung ventilation,and with a tidal volume 6 ml/kg and respiratory rate 12-16 breathes/min during one-lung ventilation,PEEP=5 cmH₂O.The inspiratory/expiratory ratio was 1:2,pressure restriction was 35 cmH₂O,and 60%oxygen was inhaled at 2 L/min.The end-tidal pressure of carbon dioxide was maintained at 35-40 mmHg.The two groups were treat with alveolar recruitment maneuvers.Visual analog scale score was maintained?3 after operation.Peak airway pressure?Ppeak?,mean airway pressure?Pmean?,chest compliance?Cydn?,and airway resistance?Raw?were recorded at the time of 15 minutes after intubation and turn to the lateral position,15 and 60minutes after one-lung ventilation,and 15minutes after the resumption of two lung ventilation.After admission to the operation room?D₀?and at 1,3 and 7 days after operation(D_1-3),forced vital capacity?FVC?,forced expiratory volume at the first second?FEV₁?,and maximal expiratory flow?MMEF?were measured,arterial blood sample were collected for blood gas analysis and for determination of TNF-?and IL-6.Arterial carbon dioxide partial pressure?PaCO₂?and arterial oxygen partial pressure?PaO₂?were recorded,and alveolar-arterial oxygen tension difference(P_A-a O₂)was calculated.Clinical Pulmonary Infection Score was assessed at D₀,D₁,D₂ and D₃.The chest tube removal time and the length of postoperative hospital stay were recorded.The probability of postoperative pulmonary complications were recorded.Result Compared with T_0,the two groups ofPpeak,Pmean and Raw were significantly higher at T₁^T₃?P<0.05?.The Cydn was decreased at T₁^T₃?P<0.05?.Compared with group V,Ppeak,Pmean and Raw decreased at T₁^T₃?P<0.05?,Cydn was higher in group P at T₁^T₃?P<0.05?.Compared with the baseline at D₀,the two groups of FVC,FEV₁ and MMEF were significantly lower at D₁^D₃?P<0.05?.The PaO₂ were decreased at D₁^D₃?P<0.05?,and the level of P_A-a O₂ was significantly increased at D₁^D₃.Compared with group V,FVC,FEV₁,MMEF increased at D₁^D₃?P<0.05?,PaO₂ was higher in group P at D₁^D₃?P<0.05?,P_A-a O₂was significantly lower than that of group V?P<0.05?.CPIS score in group P was obvious lower than that in group V?P<0.05?.There was significant difference between group V and group P for the time of chest tube removal and the time of operation to discharge?P<0.05?.Compared with the baseline at D₀,the two groups of TNF-?and IL-6 increased at D₁^D₃?P<0.05?,TNF-?and IL-6 was lower in group P at D₁^D₃?P<0.05?.There was no significant difference between group V and group P for the probability of postoperative pulmonary complications?P>0.05?.ConclusionPCV-VG mode can achieve lung protective ventilation,which is helpful in improving outcomes in the patients requiring OLV during thoracoscopic surgery.