Application Of Regional Cerebral Oxygen Saturation Monitoring In Patients With Carotid Atherosclerotic Stenosis Undergoing Off-pump Coronary Artery Bypass

Background Regional cerebral oxygen saturation?rSO₂?monitoring can detect early oxygen supply,demand balance and cerebral blood flow abnormalities in the brain region,and can be continuously monitored,no invasive injury,and data reproduction function for patients with surgery,it plays an important guiding role for perioperative brain tissue oxygenation and blood flow regulation management.At the same time,rSO₂ is related to blood pressure,hemoglobin content,body temperature,cerebral perfusion,cardiac output,etc.It can continuously and non-invasively monitor brain tissue metabolism,showing changes in oxygen supply and demand balance.China's Cardiovascular Disease Report in 2017 pointed out that the number of cardiovascular diseases is about 290 million,and the number of patients undergoing heart surgery with cerebrovascular disease is increasing.Therefore,how to prevent perioperative cerebrovascular accidents in such patients has received more and more attention.This type of serious complications has a high mortality rate.Those coronary atherosclerosis patients who need to have an operation of coronary artery bypass grafting?CABG?,9%-36%with carotid atherosclerotic stenosis?CAS?in them,CAS is one of the important risk factors of cerebrovascular disease,especially with stroke.The rSO₂monitoring and feedback interventions can reduce the incidence of neurological complications?such as stroke,paralysis,postoperative cognitive dysfunction?after cardiac surgery,and shorten the length of hospital stay.However,most of the studies focused on the occurrence of cerebral hypoxia in cardiopulmonary bypass?CPB?,and the research of cerebral oxygen saturation in patients with off-pump coronary artery bypass?OPCAB?with CAS is very rare.The probability of intracerebral hypoxia is high in such patients.It is important to study how to improve the perioperative brain protection of such patients.Objective To observe the changes of rSO₂ in the perioperative period of OPCAB in patients with CAS and patients without CAS,and to explore the significance of rSO₂monitoring in OPCAB patients with CAS.Methods Thirty patients with OPCAB were selected and divided into experimental group?group A,15 cases with CAS?and control group?group B,15 cases without CAS?according to the results of preoperative ultrasonic examination.Routine anesthesia induction was maintained in both groups.Intraoperative rSO₂ was not less than 20%of the baseline value or 50%of the absolute value.Arterial blood was collected at 5time points:T₁?before tracheal intubation?,T₂?when left anterior descending artery was anastomosed?,T₃?when far-end artery was anastomosed?,T₄?when aorta was anastomosed?and T₅?6 days after operation?.Blood gas results,mean arterial pressure?MAP?,heart rate?HR?,hemoglobin?HGB?,rSO₂ were recorded,and recovery time and trachea intubation extubation time were also recorded.Mini-mental State Examination?MMSE?was used to assess the cognitive function of patients before and 1 and 3 days after operation.SPSS 21.0 was used for data analysis.Results ?1?rSO₂ in group A and group B showed a downward trend between T₁ and T₄,and the most obvious decline was at T₃.But it showed an upward trend after T₄,with gradually returned to the preoperative level.?2?SO₂ in group A decreased more at T₃ than that in group B?P<0.05?,and PO2 in group A decreased more at T3 than that in group B?P<0.05?.?3?The MMSE score of group A was significantly lower than that of group B?P<0.05?,and the recovery time and extubation time of group A were longer than those of group B?P<0.05?.Conclusions ?1?The perioperative changes of rSO₂ in patients of OPCAB with CAS is similar to those in patients without CAS.The performance showed a downward trend after the start of OPCAB,and it was the most obvious when operation was anastomosed to the distal coronary artery.It showed an upward trend after the end of OPCAB and gradually returned to the preoperative level.?2?The decrease of rSO₂ in OPCAB of patients with CAS is greater than that of patients without CAS.The application of rSO₂ monitoring in OPCAB of patients with CAS can detect cerebral ischemia and hypoxia more timely and effectively.Take timely intervention measures for a high level of rSO₂ may avoid the occurrence of brain complications and improve prognosis.