Study schedule
| Study component | Visit 1 | Visit 2 | Visit 3 | Visit 4 | Visit 5 | Visit 6 | Visit 7 | Visit 8 | Visit 9 |
| Time | 1 day before surgery | After general anaesthesia | End of surgery | 2 hours after surgery | 6 hours after surgery | 12 hours after surgery | 24 hours after surgery | 48 hours after surgery | Discharge |
| Eligibility screen | X | − | − | − | − | − | − | − | − |
| Informed consent | X | − | − | − | − | − | − | − | − |
| Demographic characteristics | X | − | − | − | − | − | − | − | − |
| Randomisation | X | − | − | − | − | − | − | − | − |
| Intervention | − | X | − | − | − | − | − | − | − |
| Intraoperative opioid consumption | − | X | − | − | − | − | − | − | |
| FACES | − | − | − | X | X | X | X | X | − |
| Adverse events | − | − | − | − | − | − | − | X | − |
FACES, Wong-Baker Faces Pain-rating Scale.