The goal of this clinical trial is to learn about the effect of intraoperative infusion of subanesthetic dose of esketamine on conscious status in patients with prolonged disorders of consciousness under sevoflurane anesthesia.

Participants will be patients with prolonged disorders of consciousness undergoing surgery with general anesthesia at Beijing Tiantan Hospital. 0.3mg/kg esketamine or saline will be infused will be infused intravenously at a constant speed within 30 min after tracheal intubation/pneumatectomy fixation. Coma recovery scale-revised, Glasgow coma scale, Full Outline of UnResponsiveness scores, SedLine multi-channel electroencephalogram and perioperative adverse events after surgery will be investigated.

Inclusion Criteria:

1.16-65 years old 2.Native Chinese language 3.pDoC after acquired brain injury 4.Scheduled to undergo surgery 5.Signed informed consent

Exclusion Criteria:

1. Continuous sedation treatment was carried out within 72 hours before the study
2. Airway stenosis and severe ventilation or ventilation dysfunction caused by various reasons
3. Known or suspected to have serious cardiac, pulmonary and renal dysfunction 1)Severe cardiac dysfunction: a. unstable coronary syndrome b. Congestive heart failure: left ventricular ejection fraction less than 50%, elevated BNP c.Severe arrhythmia d. History of severe valvular disease 2)Severe pulmonary dysfunction: a. history of pulmonary heart disease b. History of chronic obstructive pulmonary disease 3)Severe renal dysfunction: a. Endogenous creatinine clearance (Ccr) less than 30ml/min b. The glomerular filtration rate (GFR) was less than 30ml/min•1.73m2
4. Allergic history of sedative drugs
5. Combined with other mental or nervous system diseases
6. Other reasons are not suitable for this study.