Blinding: Both patient and treating physician will be aware of the treatment assignment. Post-procedural functional outcomes will be performed by a dedicated clinician blinded to the treatment assignment. Interventions: Physiological Parameters: Target Values (Talke et al., 2014) • Oxygenation: Maintain SpO2 > 92% and PaO2 > 60 mmHg. • Ventilation: Maintain normocapnia, PaCO2 35-45 mmHg under GA. Avoid respiratory-induced hypercarbia during sedation • Hemodynamics: Systolic blood pressure > 140 mmHg and < 180 mmHg. Diastolic blood pressure < 105 mmHg. • Temperature: Maintain normothermia, T 35°C - 37°C. • Glucose control: Maintain blood glucose concentration 4.0 - 8.0 mmol/L. If blood glucose levels greater than 8 mmol/L (140 mg/dL) IV insulin infusion to be commenced. Blood glucose concentration to be repeated after 30 minutes. Hypoglycemia as defined by blood glucose < 3 mmol/L (50 mg/dL) should be treated with IV 10-20% glucose. General Anesthesia Protocol: (Melinda J. Davis, Cynthia R. Campos-Herrera, & David P. Archer, 2012; Powers et al., 2015; Talke et al., 2014) 1. Monitoring • American Society of Anesthesiologists (ASA) standard (non-invasive blood pressure (BP), electrocardiogram (ECG), oxygen saturation (SpO2), end-tidal carbon dioxide (ETCO2), temperature and neuromuscular monitoring (NMM)) • Invasive BP: direct measure of the arterial BP, with continuous pressure transduction and waveform display is the standard for blood pressure monitoring in AIS. It allows continuous BP assessment and provides reliable vascular access for frequent sampling. However, benefits of invasive arterial monitoring are null if the procedure itself delays reperfusion therapy (Saver, 2006). There is no consensus regarding timing of arterial access in EVT for AIS. This is our protocol: • 1 attempt with the patient awake • Maximum of 2 more attempts with the patient under anesthesia • Stop after a total of 3 attempts, or when the radiologist has access to the femoral artery. 2. Induction of anesthesia. 3. Neuromuscular paralysis. 4. Endotracheal intubation. 5. Positive pressure ventilation: ETCO2 range: 35-40 mmHg until arterial partial pressure of carbon dioxide (PaCO2) is obtained and the gap is measured. 6. Volatile anesthesia with sevoflurane or desflurane to a target age-compensated minimum alveolar concentration (MAC) > 0.5 but = 1(Sivasankar et al., 2016) 7. Vasopressor support: If the systolic BP decreases more than 20% from pre-anesthetic value or is lower than 140 mmHg, the patient will receive vasopressor support as IV phenylephrine and/or ephedrine, titrated to effect. 8. Hypertension management: For systolic BP > 180 mmHg, IV labetalol will be administered, titrated to effect. 9. Arterial blood gas sampling to be performed at the earliest convenience after induction of anesthesia. Clinical goals are outlined above. 10. Temperature monitoring wit esophageal temperature probe. 11. Antagonism of neuromuscular blockade at the end of the procedure. The train of four should be = 0.9 prior to extubation (Hassan et al., 2012; Murphy GS, 2015). 12. Transfer the patient to the post-anesthesia care unit (PACU). Sedation Protocol: 1. Monitoring • ASA standard (non-invasive BP, ECG, SpO2, T, respiratory rate (RR), and ETCO2) • Invasive BP: a direct measure of the arterial blood pressure, • Maximum 3 attempts. Stop after a total of 3 attempts, or when the radiologist has access to the femoral artery. 2. Administer oxygen by nasal prongs or facial mask to achieve a target Sp02 = 92%. 3. Commence sedation: Remifentanil: 0.01-0.06 micrograms/kilogram/minute, titrated to effect. (Janssen et al., 2016) 4. Monitor RR. Decrease sedative infusion rate if RR < 6. 5. Vasopressor support: If the systolic BP decreases more than 20% from pre-anesthetic value or if is lower than 140 mmHg, the patient will receive vasopressor support as IV phenylephrine and/or ephedrine, titrated to effect. 6. Hypertension management: For systolic BP > 180 mmHg, IV labetalol will be administered, titrated to effect. 7. Arterial blood gas sampling to be performed at the earliest convenience after induction of anesthesia. Clinical goals are outlined above. 8. Temperature monitoring with axillary temperature probe. 9. Transfer the patient to the PACU.