Local Anaesthetic Systemic Toxicity

This prospective single-center observational pharmacokinetic study will evaluate plasma levobupivacaine concentrations after ultrasound-guided transversus abdominis plane (TAP) block in adult patients undergoing elective abdominal surgery under general anesthesia at CHU Liège. Participants receiving TAP block as part of standard clinical care (levobupivacaine 0.375%, total volume 40 mL, maximum dose 150 mg) will undergo serial blood sampling at 3, 7, 15, 30, 60, 120, and 180 minutes after block completion. Plasma levobupivacaine concentrations will be measured using validated LC-MS/MS methods. The primary objectives are to estimate maximum plasma concentration (Cmax) and time to maximum concentration (Tmax). Secondary objectives include characterization of the concentration-time profile, AUC0-180, interindividual variability, and exploratory associations with clinical factors (age, sex, BMI, type of surgery). The study also aims to inform a pragmatic safety window for subsequent intravenous lidocaine infusion used in multimodal analgesia protocols. Approximately 26 participants will be enrolled. No modification of routine anesthesia or analgesic care is required apart from study-related blood sampling.

This randomized controlled trial evaluates whether perioperative intravenous lidocaine infusion, combined with port-site ropivacaine infiltration, improves postoperative recovery after laparoscopic abdominal surgery. Participants will be assigned 1:1 to receive either intravenous lidocaine during surgery plus ropivacaine infiltration at surgical closure, or ropivacaine infiltration alone. The primary endpoint is postoperative quality of recovery measured by the QoR-15 questionnaire. Secondary endpoints include postoperative pain and opioid consumption, as well as plasma lidocaine and ropivacaine concentrations to assess systemic exposure and safety.