Table 1

Schedule of enrolment, interventions, data collection and outcome assessments

Time pointOperationPostoperation follow-up
PreoperationDuring operation2 days after surgery5 days after surgery3 months6 months
Enrolment
 Eligibility screen✖
 Recruitment✖
 Consent✖
Randomisation and allocation✖
Intervention
 Opioid-free anaesthesia group or opioid-based control group✖
Prerandomisation data collection
 Demographics✖
 Physical examination✖
 Laboratory results✖
 Neurological examination✖
Daily data collection
 Intraoperative vital signs✖
 The use of antiemetic drugs✖
 The use of analgesic drugs✖✖✖✖
 Laboratory results✖✖
Primary outcome
 QoR-15 Score on the second day after surgery✖
Secondary outcomes
 QoR-15 Score on the fifth day after surgery✖
 Postoperative nausea and vomiting✖
 NRS Pain Score✖✖✖✖
 Postoperative sleep quality✖✖

  • NRS, Numerical Rating Scale; QoR, quality of recovery.