Effects of S-ketamine on recovery quality in elderly patients with impaired intrinsic capacity after total knee arthroplasty: a single-centre, randomised, double-blind, placebo-controlled study protocol.

INTRODUCTION

Elderly patients with impaired intrinsic capacity are at increased risk for delayed or suboptimal recovery from surgery. S-ketamine has been proven to improve postoperative recovery quality. However, limited trials are studying the postoperative recovery quality in elderly patients with impaired intrinsic capacity. Therefore, the objective of this study was to evaluate the impact of S-ketamine on the quality of recovery in elderly patients with impaired intrinsic capacity following total knee arthroplasty.

METHODS AND ANALYSIS

This is a single-centre, randomised, double-blind, placebo-controlled trial. Participants undergoing total knee arthroplasty will be randomly assigned in a 1:1 ratio to either the S-ketamine group (n=80) or the placebo group (n=80). The S-ketamine group will undergo an intravenous infusion of S-ketamine administered at a dosage rate of 0.2 mg·kg⁻·h⁻ for 1 hour. The placebo group will receive an intravenous saline infusion at an identical rate and duration. Postoperatively, the S-ketamine group will continuously infuse S-ketamine for 48 hours using a patient-controlled intravenous device, with a fixed rate of 0.01 mg·kg⁻¹·h⁻¹, a bolus dose of 0.02 mg·kg⁻¹, a lockout period of 10 min and a maximum infusion rate of 0.13 mg·kg⁻¹·h⁻¹. In contrast, the patient-controlled intravenous device for the placebo group will not contain S-ketamine. The primary outcome is the quality of recovery scores at 24 hours following total knee arthroplasty. Secondary outcomes encompass quality of recovery scores at 48 and 72 hours postoperatively, pain scores at rest and during movement, oral morphine equivalents, sleep quality assessments, depression scores, the Barthel Index and the time to meet discharge criteria.

ETHICS AND DISSEMINATION

Approval for the trial was granted by the Medical Ethics Committee of The Affiliated Hospital of Qingdao University (QYFYEC2024-74). Written informed consent will be obtained from each patient before enrolment. The results of this trial will be presented at scientific conferences and in peer--reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR2400087028.