The Effect of a Single Intravenous Injection of Esketamine During Cesarean Section on Postoperative Pruritus in Patients With Intrahepatic Cholestasis of Pregnancy

Inclusion Criteria: 1. Age: 18 - 40 years old; Gestational age: ≥ 35 weeks; Singleton pregnancy. 2. Clear consciousness, able to cooperate with NRS scoring, laboratory tests and follow-up. 3. Meet the diagnostic criteria of the "Clinical Diagnosis, Treatment and Management Guidelines for Intrahepatic Cholestasis of Pregnancy (2024 Edition)" : fasting serum TBA≥10 μmol/L or postprandial serum TBA≥19 μmol/L. 4. Reporting pruritus NRS ≥ 4 points twice within one week. 5. Planned to undergo cesarean section under intraspinal anesthesia. 6. ASA classification: I - III grade. Exclusion Criteria: 1. Those who are known to be allergic to the drug components or have an allergic constitution. 2. Related to the safe use of esketamine: history of mental illness; uncontrolled hypertension; uncontrolled hyperthyroidism; increased intracranial pressure, increased intraocular pressure; long-term alcohol consumption or drug abuse history. 3. Those with severe organic diseases and liver diseases. 4. Those with malignant tumors. 5. Other pruritic diseases: uremic pruritus, true erythrocytosis, cutaneous T-cell lymphoma, eosinophilia, drug rash and drug-induced pruritus, and other pruritic diseases that are easily confused, such as atopic dermatitis, pemphigus, scabies, parasitic delusionism, artificial dermatitis, etc. 6. Eclampsia and pre-eclampsia, HELLP syndrome; fetal developmental abnormalities, multiple pregnancies. 7. ASA classification as grade IV. 8. Those with poor compliance and unable to complete the trial according to the research protocol. 9. Those who have participated in other drug clinical trials within the past 4 weeks. 10. Due to any reason, the researchers consider that there is any situation that is not suitable for inclusion. \-