Application Of Tee Evaluation Of The Left Lateral Position With Low Tidal Volume End-expiratory Positive Pressure Single-lung Ventilation In Patients With Hemodynamic Changes

Background The current view about the management of one-lung ventilation is adopting low tidal volume and positive end-expiratory pressure (PEEP). This method, compared with traditional way with large tidal volume (8-12ml/kg), may provide effective oxygenation and carbon dioxide exchange with reduced perioperative acute lung injury. However, the effect of this new management on hemodynamic status is not well known yet.Objective To evaluate the hemodynamic status in left lateral position with low tidal volume and positive end-expiratory pressure application in one-lung ventilation by transesophageal echocardiography (TEE).Methods 10 ASAⅠorⅡstatus patients undergoing elective right lung lobectomy in left lateral position were included in the study. After induction of anesthesia, ventilation parameters were set at TV 4～6 ml/kg, PEEP 4～6cmH₂O, RR 12～16/min, maintaining EtCO₂ 35-40mmHg and SpO2>96%. 30min later (about 15min after central venous line insertion), HR, BP and CVP were recorded. EF, SV, CO, CI, SI, ESV, EDV, DFS, and SVR were measured by TEE through transgastric left ventricle short axis view at same time during two-lung ventilation in supine position. Then, the patient was turned to left lateral position. One-lung ventilation was set just before thoracic cavity opened and all the same hemodynamic data were repeatedly measured 15min later.Results There were no significant difference in HR, SBP, DBP, CVP, EF, CO, CI, LVESV, LVEDV, LVDFS and SVR between left lateral one-lung ventilation and supine two-lung ventilation with low tidal volume and PEEP. However, the SV and SI were significant increased in left lateral one-lung ventilation. Conclusion We conclude that in patients with low tidal volume and PEEP ventilation mode, compared with two-lung ventilation in supine position, the hemodynamic status and cardiac function were not changed after the patients turned to left lateral one-lung ventilation. EF, CO and CI did not change although SV and SI significant increased.