Effect Of Ventilation Strategy Combined With Blood Pressure Regulation On Cerebral Oxygen Saturation And Postoperative Cognitive Function In Beach Chair Position Surgery

Objective To investigate the effects of different ventilation strategies combined with blood pressure regulation on brain oxygen saturation and postoperative cognitive function in patients with beach chair position.Methods 60 patients in beach chair posture surgery under general anesthesia were randomly divided into four groups,group A: F_iO₂ 0.4 and PETCO₂ 30-35 mm Hg;group B: F_iO₂ 1and PETCO₂ 30-35 mm Hg;group C: F_iO₂ 1.0 and PETCO₂ 40-45 mm Hg;group D: F_iO₂0.4 and PETCO₂ 40-45 mm Hg.When the patients take the beach chair position,the PETCO₂ can be maintained by adjusting the breathing frequency.Using vasoactive drugs to control blood pressure maintain 60-70 mm Hg in all groups,and recorded the MAP and rSO₂ after induction of anesthesia（T1）,5min after the beach chair position（T2）,5min after ventilation control strategy（T3）,30 min after ventilation control strategy（T4）,60 min after ventilation control strategy（T5）and 5min after supine（T6）.Recorded MMSE score before and after 24 hours and 7 days after operation.Results Compared with T1,the T2 time point MAP and rSO₂ decreased in the four groups,and had statistical significance.After adjusting the ventilation frequency,compared with group A,B and D group had higher rSO₂ at T3-T5 time.Compared with B group,T3-T5 group had higher rSO₂ time than T3-T5 group;compared with D group,the time of rSO₂ in C group was higher.Compared with T5,the T6 time point rSO₂ increased significantly in the four groups,and the difference was statistically significant.There was no significant difference in MMSE between the four groups before and after the operation.Conclusion Lower oxygen inhalation and higher end tidal carbon dioxide combined with blood pressure control can maintain cerebral perfusion well in patients with beach chair position,and provide good surgical field for shoulder arthroscopic surgery.