Effect of Postoperative Prolonged Sedation With Dexmedetomidine After Successful Reperfusion With EVT on Long-term Prognosis in Patients With AIS (PPDET)

Inclusion Criteria: * 2≤NIHSS≤25 * mRS score before stroke was less than 3 * Acute ischemic stroke (including anterior circulation) * mTICI rate 2b or 3 * According to the 2018 AHA/ASA guidelines for the management of acute ischemic stroke, patients who plan to receive mechanical thrombectomy under local anesthesia and sedation * Informed consent was signed by patient or legal representative Exclusion Criteria: * Intracerebral hemorrhage occurred in the responsible vessel area in the past 6 weeks * Patients who had received stent treatment at the responsible vessel in the past * Neurological function was restored at or before angiography * Patients who are allergic to heparin, aspirin, clopidogrel, rapamycin, lactic acid polymer, poly (n-butyl methacrylate), stainless steel, anesthetics and contrast agents or have contraindications * Hemoglobin was less than 70g/L, platelet count was less than 50×109/L, international normalized ratio (INR) greater than 1.5 (irreversible), there are uncorrectable bleeding factors * Blood glucose \< 2.7 mmol/L or \> 22.2 mmol/L * Severe liver or kidney disfunction, ALT\>3 times the upper limit of normal value or AST\>3 times the upper limit of normal value, creatinine\>1.5 times the upper limit of normal value * Pregnant or lactating women * Previous history of mental illness * Stroke with other acute diseases or postoperative stroke of other operation * Heart rate less than 50bpm, second or third degree of atrioventricular block (except for pacemaker implantation), systolic blood pressure less than 90mmHg (two vasoactive drugs were already infused continuously )