Relationship Between Carotid Disease And POCD And The Value Of RScO₂

Objective:Postoperative cognitive dysfunction?POCD?is a manifestation of brain dysfunction,and the brain function is closely related to the balance of blood supply and oxygen consumption.Carotid is the main artery of blood supply to the brain.Structure and hemodynamic changes of carotid are both important to cerebral perfusion.We can monitor the structure and function changes of carotid using ultrasonography technology in perioperative period.In addition,oxygen supply and consumption of brain can be measured by cerebral tissue oxygen saturation?rScO₂?.This study aims to explore the relationship between carotid lesion and POCD,and the value of using intraoperative rScO₂in total joint arthroplasty?TJA?under general anesthesia,by combining monitoring carotid ultrasonography,intraoperative rScO₂ and POCD diagnosis.Methods:47 selective TJA patients,were applied neuropsychological scale the day before surgery,day of surgery,first day after surgery and seventh day after surgery to assess changes of cognitive function,were continuously monitored rScO₂ during anesthesia,and their carotid intima-media thickness?IMT?and intraoperative hemodynamic parameters were monitored during anesthesia,including maximum velocity?Vmax?,end diastolic velocity?ED?,systolic peak velocity/end diastolic velocity?S/D?,R-R interval?RT?,flow volume FV,resistance index?RI?,pulsatility index?PI?and minimum speed?Mn?.Result:The proportion of low rScO2 in patients of POCD the day of surgery was significantly higher than that in non POCD?P=0.015?;rScO₂ decline in patients with increased IMT was significantly more than that in patient with normal IMT?P=0.010?;in the group with increased IMT,among patients of POCD first day after surgery and 7th days after surgery,Mn were difficult to increase after induction?P=0.008,P=0.003?;in the group with low rScO₂,among patients with increased IMT,ED were lower?P=0.027?,S/D were higher?P=0.023?and increase trend of Vmax were worse?P=0.049?when rScO₂ declined;in the group with low rScO₂,among patients with carotid stenosis,increase trend of PI was better?P=0.044?when rScO₂ declined.Conclusion:Intraoperative rScO₂ decline is associated with POCD the day of surgery;increased IMT and decrease of intraoperative rScO₂ are correlated;carotid atherosclerotic disease leading vessel wall stiffness increase can cause the increase of pulsatile of cerebral blood flow perfusion,leading to influence intraoperative brain activity intra and even post operative cognitive function.Carotid atherosclerotic disease is a pre factor of POCD.It can be predicted by ultrasound before operation,and rScO₂ monitoring is also an effective intraoperative assessment.