A Prospective Cohort Study of Perioperative Covert Stroke and Postoperative Cognitive Dysfunction

Study Overview
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Brief Summary
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With the development of population aging, the incidence of covert stroke and cognitive dysfunction gradually increased. Currently, there is still lack of prospective cohort study with large sample size on the relationship between perioperative covert stroke and postoperative cognitive dysfunction. The investigators will perform a prospective cohort study. The aim of the study is to determine whether there is an association between perioperative covert stroke and postoperative cognitive dysfunction in elderly patients undergoing noncardiac surgery.

Official Title
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A Prospective Cohort Study of Perioperative Covert Stroke and Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Noncardiac Surgery

Conditions
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Anesthesia, Postoperative Cognitive Dysfunction, Covert Stroke

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients schedule to receive elective noncardiac surgery under general anesthesia will be included in the trial. Other criteria include age older than 60 years old. Exclusion Criteria: Patients have MRI contraindications, and cannot complete the cognitive evaluation and refuse to sign informed consent will be excluded from the trial.

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Perioperative covert stroke<br> | |
| Postoperative cognitive dysfunction<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of perioperative covert stroke | Stroke is diagnosed by MRI | Postoperative 3-7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative cognitive function | Cognitive assessment will be conducted by trained research members who are blinded to the clinical diagnosis, treatment and MRI. The Mini-mental State Examination (MMSE) and Montreal cognitive assessment-basic (MoCA-B) will be used to assess the cognitive function. Postoperative cognitive dysfunction is defined as at least 2 standard deviation reduction in either assessment of MMSE or MoCA-B. | 1 day before surgery; and 3 months, 1 year after surgery | 
| Postoperative delirium | The Confusion Assessment Method for the Intensive Care Unit scale (CAM-ICU) will be applied to assess delirium. | 4 hours, 24 hours, and 7 days after surgery | 
| Recovery quality | The Modified Rankin Scale (mRS) and Lawton instrumental activities of daily living scale (IADL) will be applied to assess the recovery quality. | 1 day before surgery; and 30 days, 3 months after surgery | 
| The quality of life | The quality of life will be assessed with the EuroQol-5D (EQ-5D) scale. | 1 day before surgery; and 30 days, 3 months after surgery | 
| Depression state | Depression state will be assessed with the Geriatric Depression Scale. | 1 day before surgery; and 30 days, 3 months after surgery | 
| The incidence of comorbidity. | The incidence of myocardial infarction, cardiac arrest, pulmonary embolism, sepsis, surgical site infection and persistent postoperative pain. | 30 days and 3 months after surgery |