Clinical Research Directory

Inclusion Criteria: 1. Aged 18 years or above; 2. Single term cephalic pregnancy preparing for vaginal delivery; 3. Agreed to receive epidural labor analgesia. Exclusion Criteria: 1. History of schizophrenia or epilepsy; 2. Presence of contraindications for epidural analgesia, including: (1) history of infectious disease of the central nervous system (poliomyelitis, cerebrospinal meningitis, encephalitis, etc.); (2) history of spinal or intra-spinal disease (trauma or surgery of spinal column, intra-spinal canal mass, etc.); (3) systemic infection (sepsis); (4) skin or soft tissue infection at the site of epidural puncture; (5) coagulopathy. 3. Relative contraindications for the use of dexmedetomidine, including prenatal bradycardia (HR\<60 beats per minute) and second-degree or higher atrioventricular block; 4. Relative contraindications for the use of esketamine, including uncontrolled hypertension (systolic blood pressure \>180 mmHg) and hyperthyroidism; 5. Not well controlled systemic diseases, including heart disease, liver disease, kidney disease, or an ASA classification \>III; 6. Other conditions that are considered unsuitable for study participation.