The Clinical Application Of Lung Protective Ventilation Strategies In The Video Assisted Thoracic Lobectomy

Video assisted thoracic surgery(VATS)has been widely used in general thoracic surgery and lymphnode dissection,including parts of the complex trachea and pulmonary vessels angioplasty.the relevant to anesthetic technology,especially intraoperative ventilatory presents new challenges: the greatest degree of lung collapse,to ensure that the vision and operation space of VATS;reduction of tidal volume to reduce mediastinal swing,increased operation time,increased dependence on the one lung ventilation(OLV).OLV of VATS requires high concentration of pre-inspiratory and high fraction of inspiration oxygen,long time of lung collapse etc,so induces more severe atelectasis,and resulting in V / Q imbalance and may lead to lung injury.And the VATS surgery because of the micro operation port,the surgeon need clamping and drawing lung for long time.A large number of the use of metal staples for cutting lung tissue,vessels,tracheas,more electrotome,ultrasonic,ligature,they might increased the odds of lung injury;According to the multiple hit theory,the mechanical ventilation is one of the reasons cause lung injury,so for anesthetists,we should cooperating to VATS surgery,at the same time,also need to considering the ventilation settings,The lung protective ventilatory strategy is proposed during OLV,including reduction of tidal volume,and with the appropriate end expiratory positive pressure(PEEP),appropriate alveolar recruitment maneuver(RM),etc.these strategies mainly reference from the acute respiratory distress syndrome(ARDS)patients with mechanical ventilation treatment,but such a method is beneficial in general anesthesia with OLV is controversial.That how to implement specific protection strategy is a cause of the dispute: how to set the appropriate PEEP during VATS,how and when manipulate RM,including the frequency;this subject that is mainly discusses how to setting PEEP,and whether the setting cause hemodynamic changes.and two RM's advantages and disadvantages.Objective To establish the advantage and feasibility of using dynamic compliance identify the positive end-expiratory pressure(PEEP)level in OLV of VATS lobectomy.And investigate the hemodynamic effects of different positive end-expiratory pressure,The different of two alveolar RM in the bilateral simultaneous VATS lobectomy.Methods This study is divided into three parts of experiment :in the first part,80 patients undergoing video-assisted right pulmonary lobectomy were randomly allocated to two groups.Group A received an alveolar recruitment sustained inflation(SI)at the beginning of one-lung ventilation,then ventilated with an individualized PEEP level determined by a PEEP decrement trial which use dynamic compliance.After the same alveolar recruitment with group A,group B was ventilated with 5 cmH2 O PEEP.Arterial blood gas analysis,lung mechanics were recorded at 5 time points throughout the procedure.In the second part,36 patients who under OLV of VATS,were placed Doppler probe through their nostril to monitor the blood flow parameters,and then recorded them respectively which with 5cmH2 O ? 10cmH2 O PEEP.In the third part,40 patients undergoing bilateral simultaneous pulmonary lobectomy were randomly allocated to group A and group B.all the patients take wedge resection first and turn over,take another lobe resection.after turn over,group A received sustained inflation of 40cmH2 O maintained 15 s.group B ventilation by PCV with a driving pressure of 20 cmH2 O.PEEP was increased in 5 cmH2 O steps and was held for 10 breaths.A opening pressure of 40cmH2O(20 cmH2 O PEEP)was applied for 20 breaths.Arterial blood gas analysis,blood pressure,CVP,lung mechanics were recorded at each timepoints throughout the procedure.Results In the first part :the PEEP values[group A(9.2�1.2)cmH2O,group B 5cmH2O]was significantly different between two groups(P<0.05),partial pressure of oxygen(PaO2)at T3(1 h after one lung ventilation)? T4(operation ending)was significantly different in two groups[group A(244�71)mmHg(1 mmHg=0.133 kPa)?(240�63)mmHg,group B(212�61),(188�50)mmHg)(P<0.05)],During one-lung ventilation,PaO2 at T3?T4was decreased in group B(P<0.05),but it was maintained in group A(P>0.05).The dynamic compliance have the same results[group A:T3(30.8�5.9)ml/cmH2 O,T4(30.7�6.4)ml/cmH2O),group B:[T3(26.6�5.5)ml/cmH2 O,T4(26.4�5.2)ml/cmH2O(P<0.05)].In the second part: compare with 5cmH2 O PEEP that the10cmH2 O got decreased CO?CI?SV?FTc?MAcc?SVR,but there were no significantly different(P>0.05);and the PVel ? dPV were increased but still no significantly different(P>0.05);the peak pressure,plat pressure,ETCO2,lung compliance have significantly different(P<0.05).In the third part,When the patients received RM,the systolic pressure in group A was lower than group B(P<0.05).after RM the PaCO2-Et CO2 in group A was lower than group B(P<0.05).but PO2 and CVP did not have significant difference(P>0.05).Conclusions The PO2 and lung mechanics were better maintained by using PEEP with decrement trial than 5 cmH2 O PEEP during one-lung ventilation that undergoing video-assisted pulmonary lobectomy.seting 5cmH2 O or 10cmH2 O PEEP have no significantly hemodynamic effects druing one lung ventilation.In the bilateral simultaneous pulmonary lobectomy,RMwith PCV/PEEP(group A)have less circular effects,but SI(group B)have more efficient,just need monitor vital signs.