General Anaesthesia vs Spinal Anaesthesia: Patient Outcomes and Success in Outpatient Primary Total Knee and Hip Arthroplasty

Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common operations used to treat severe joint disease, most often caused by osteoarthritis. An increasing number of these procedures are now performed as outpatient surgery, meaning that patients can go home on the same day as the operation. This can be beneficial for both patients and healthcare systems, but it requires safe and efficient anaesthetic care. Two different types of anaesthesia are commonly used for these operations: general anaesthesia (where the patient is asleep) and spinal anaesthesia (where the lower part of the body is numbed). Both methods are well established and widely used. Previous studies suggest that the choice of anaesthesia may affect how quickly patients recover, how comfortable they feel after surgery, and whether they can be safely discharged on the day of surgery. However, most existing studies are based on retrospective data, and there is limited randomized evidence comparing these anaesthetic techniques in the outpatient setting. The GASPS trial is a multicentre, randomized, phase IV clinical study that compares general anaesthesia and spinal anaesthesia in adults undergoing outpatient primary total knee or hip arthroplasty. A total of 600 participants will be included and randomly assigned to receive one of the two anaesthetic methods on the day of surgery. All participants will receive standard surgical and perioperative care, and both anaesthetic techniques are part of routine clinical practice. The main aim of the study is to investigate whether the type of anaesthesia influences the chance of successful same-day discharge, defined as going home on the day of surgery without needing to be readmitted within 48 hours. The study will also examine recovery time, pain, nausea and vomiting, use of pain medication, complications, patient-reported recovery and function, and healthcare costs. In addition, patient experiences of anaesthesia and postoperative recovery will be explored through interviews in a smaller group of participants. Participants will be followed using questionnaires and medical records from the day of surgery up to 12 months after the operation. The results of this study are expected to provide clear and reliable information to help guide anaesthetic care for patients undergoing outpatient hip and knee replacement surgery.