Dexmedetomidine is a highly selective a2-adrenoreceptor agonist that produces dose-dependent sedation and analgesia without respiratory depression. Dexmedetomidine has been used in critically ill medical, surgical, and pediatric patients. No study has been designed specifically to evaluate dexmedetomidine uses in the neurocritical care population. The primary objective is to evaluate the safety and efficacy of dexmedetomidine for prophylactic analgesia and sedation in patients after intracranial surgery.

The PASTrial is a non-commercial, multi-center, randomized, placebo-controlled, double blinded clinical trial. The study compares dexmedetomidine versus normal saline (placebo) in patients after intracranial surgery with delayed extubation. In dexmedetomidine group, infusion (0.4μg/kg/h) is started when patients are admitted to neuro-intensive care unit for postoperative recovery. In control group, patients receive normal saline infusion at the same rate and volume in dexmedetomidine group. The patient's level of sedation is assessed by Sedation-Agitation Scale (SAS) per hour. Midazolam is administered in 0.3-0.5 mg bolus or continuous infusion as SAS above 4. The study is designed primarily to compare the percentage of patients with agitation and requiring midazolam infusion in the 2 study arms.

Inclusion Criteria:

• Adult patients after intracranial surgery with delayed extubation

Exclusion Criteria:

• emergency operation
• brain stem operation
• preoperative consciousness disorders or epilepsy
• bradycardia, hypotension, acute myocardial infarction, second- or third degree heart block, or need continuous infusions of vasopressor before the start of study drug infusion
• patients enrolled in another trial