Quality of Recovery After Primary Breast Cancer Surgery Comparing Thoracic Paravertebral Block and Intravenous Lidocaine Infusion.

The goal of this clinical trial is to learn whether an intravenous lidocaine infusion (IVLI) works as well as a thoracic paravertebral block (TPVB) - the current standard nerve-block technique - for improving recovery after breast cancer surgery. It will also learn about the safety of both approaches. The main questions it aims to answer are:

Does IVLI provide a similar quality of recovery (measured by the QoR-15 score at 24 hours) as TPVB? Does IVLI control pain during the first 24 hours after surgery (measured at rest and with arm movement) as well as TPVB?

Participants will:

Undergo their planned breast cancer surgery (mastectomy or breast-conserving surgery with sentinel lymph node biopsy) under general anaesthesia, along with either the TPVB injection or the IVLI infusion, assigned at random Attend a preoperative visit the day before surgery to learn how to use the pain and self-quality-of-recovery questionnaire (QoR-15) Fill out a QoR-15 once a day for the first 48 hours after surgery Participants' pain score in hospital recorded during the first 48 hours after surgery, with rescue pain medication available if needed