To explore the effect of intraoperative esketamine on pruritus in elderly patients undergoing elective general anesthesia for knee replacement surgery
Aged ≥ 65 years old;
Presenting with only skin pruritus without obvious primary skin lesions, with or without scratch-induced skin lesions;
Daily or nearly daily pruritus lasting for more than 6 weeks.
Patients undergoing elective general anesthesia for orthopedic knee arthroplasty.
Those who are allergic to the pharmaceutical ingredients of this study or have an allergic constitution;
Those with a history of allergy to general anesthetics, opioids, or non-steroidal anti-inflammatory drugs;
Those with severe cognitive impairment, a history of neurological diseases, chronic pain, drug addiction, alcoholism, long-term opioid use, or administration of opioids within 48 hours before surgery;
Patients with ASA physical status classification Grade IV-V;