Clinical Study On The Lung Collapse Accelerating Effect Of Different Ventilation Pause Time During Endoscopic Thoracic Surgery

Objectives:By evaluating the effectiveness on improving surgical side lung collapse of applying different disconnection times before one-lung ventilation during endoscopic thoracic surgery,observe the accelerated effect of lung collapse,as well as find out the most effective and the safest disconnection ventilation strategy.Methods:Seventy-three patients undergoing endoscopic thoracic surgery with physical classification ? or ? according to the American Society of Anesthesiologists were randomly divided into four groups for respiratory management of one-lung ventilation(OLV).In group P,OLV was initiated after the DLT were disconnected for 30s(P1),60s(P2),90s(P3),the initiation time began when the surgeon made the skin incision.In group C,OLV was initiated when the surgeon commenced the skin incision and scored the quality of lung collapse(using a four-point ordinal scale)after insert the 30°video thoracoscopic camera.The surgeon's satisfaction with the surgical conditions was assessed using a visual analogue scale.Mean arterial pressure,heart rate,pulse oxygen saturation,rSO2 level,arterial blood gas analysis(PaCO2,PaO2 and calculate OI)were recorded at the following 5 time points:while inhaling air(T0),after anesthesia induction and inhaling 100%oxygen in the lateral position under double lung ventilation for five mins(T1),at 2 mins after skin incision(T2),at 10 mins after skin incision(T3),and inhaling 50%oxygen for 5 mins after the lung recruitment maneuvers(T4).And recording the events of intraoperative hypoxaemia,postoperative complications including respiratory,cardiovascular,urinary and nervous system.Results:Compared with group C,the total lung collapse time of group P2,P3 was significantly shortened,the difference was statistically significant(p<0.05),while the time of lung collapse in group P1 was slightly shorter than that in group C,but there was no significant difference(p>0.05);Compared with group C,the satisfaction scores of surgeons in group P1,P2,P3 were significantly increased,the difference was statistically significant(p<0.05),and the satisfaction scores of surgeons in P2 and P3 groups were similar,and there was no statistical difference(p>0.05).At T2 time point,the PaCO2 in group P2,P3 were higher than that in group C,the difference was statistically significant(p<0.05),and rSO2 was also higher than that of C group,the difference was statistically significant(p<0.05),while PaO2 level was lower than that in group C,and the difference was statistically significant(p<0.05).There were no statistically significant differences between the incidence of intraoperative hypoxaemia and postoperative complications(p>0.05).Conclusion:Disconnection technique using a double-lumen tube may speed up the collapse of the non-ventilated lung during one-lung ventilation of the endoscopic thoracic surgery.The surgeons were satisfied with the surgical condition.60s disconnection times turn out to be the most safe and effective strategy and is expected to applied in the endoscopic thoracic surgery.