Postoperative Delirium and Its Biomarkers in Elderly Patients Undergoing Non-cardiac and Non-neurosurgery.

Study Overview
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Brief Summary
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Postoperative delirium (POD) is a common complication in elderly patients and is associated with negative clinical outcomes, such as prolonged hospitalizations, cognitive impairment, and higher mortality rate. While the pathophysiology of delirium remains unknown, the cerebral hypoperfusion and neuroinflammatory response are considered to play an important role in the process of POD. The aim of the study is to determine the association between POD and biomarkers in elderly patients undergoing noncardiac and non-neurological surgery.

Official Title
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Postoperative Delirium and Its Biomarkers in Elderly Patients Undergoing Non-cardiac and Non-neurosurgery: a Prospective Cohort Study.

Conditions
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Anesthesia, Postoperative Delirium

Intervention / Treatment
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* Other: The regional cerebral oxygen saturation (rSO2)
* Other: The glial fibrillary acidic protein (GFAP)
* Other: The brain-derived-neurotrophic factor (BDNF)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: With American Society of Anesthesiologists (ASA) physical status Ⅱ-Ⅳ Undergo elective non-cardiac and non-neurological surgery receiving general anesthesia Operation time is expected to be longer than 2 hours Exclusion Criteria: Clinical diagnosis of dementia Clinical diagnosis of cerebrovascular disorders Clinical diagnosis of heart failure Clinical diagnosis of liver failure Clinical diagnosis of renal failure Clinical diagnosis of traumatic brain injury Alcohol abuse Can not complete the cognitive assessments Refuse to sign informed consent

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 85 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 |
| --- | --- |
| Postoperative delirium<br> | Other: The regional cerebral oxygen saturation (rSO2)<br>* Measurement of rSO2 with non-invasive near-infrared light spectrum monitor. The average, left and right frontal regions absolute rSO2 values will be collected every 30 seconds during the whole surgery until postoperative 2 hours, and the mean values will be calculated. Absolute rSO2 value and AUT (area under the threshold) send beneath the absolute threshold limits of 40%, 50% and 20%, 30% under the baseline. AUT will be calculated based on this formula: AUT (present)=AUT (past)+(rSO2 threshold-rSO2 value)×sample rate<br>Other: The glial fibrillary acidic protein (GFAP)<br>* Venous blood sample will be collected and tested for plasma GFAP. The blood will be collected 10 minutes before anesthesia, 30 minutes after intubation, every hour during operation, 15 minutes after extubation, and at 10:00 AM in postoperative 1,3,5 days.<br>Other: The brain-derived-neurotrophic factor (BDNF)<br>* Venous blood sample will be collected and tested for plasma BDNF. The blood will be collected 10 minutes before anesthesia, 30 minutes after intubation, every hour during operation, 15 minutes after extubation, and at 10:00 AM in postoperative 1,3,5 days.<br>|
| Non postoperative delirium<br> | Other: The regional cerebral oxygen saturation (rSO2)<br>* Measurement of rSO2 with non-invasive near-infrared light spectrum monitor. The average, left and right frontal regions absolute rSO2 values will be collected every 30 seconds during the whole surgery until postoperative 2 hours, and the mean values will be calculated. Absolute rSO2 value and AUT (area under the threshold) send beneath the absolute threshold limits of 40%, 50% and 20%, 30% under the baseline. AUT will be calculated based on this formula: AUT (present)=AUT (past)+(rSO2 threshold-rSO2 value)×sample rate<br>Other: The glial fibrillary acidic protein (GFAP)<br>* Venous blood sample will be collected and tested for plasma GFAP. The blood will be collected 10 minutes before anesthesia, 30 minutes after intubation, every hour during operation, 15 minutes after extubation, and at 10:00 AM in postoperative 1,3,5 days.<br>Other: The brain-derived-neurotrophic factor (BDNF)<br>* Venous blood sample will be collected and tested for plasma BDNF. The blood will be collected 10 minutes before anesthesia, 30 minutes after intubation, every hour during operation, 15 minutes after extubation, and at 10:00 AM in postoperative 1,3,5 days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of postoperative delirium within postoperative 5 days | The postoperative delirium will be diagnosed if patients have fluctuation in mental status and attention and either thinking or consciousness in the past 24 hours as evidenced by fluctuation on Confusion Assessment Method-Intensive Care Unit (CAM-ICU) scale. | the incidence of delirum within postoperative 5 days. |