Ultralow concentration levobupivacaine 0.0625% for continuous wound infusion after open abdominal surgery: a prospective observational study.

Continuous wound infusion with local anaesthetics after open abdominal surgery may provide opioid-sparing analgesia, but evidence on very low-concentration regimens is limited. We conducted a prospective observational study including 50 patients receiving continuous infusion of levobupivacaine 0.0625% via pre-peritoneal or subfascial catheters at a flow rate of 12 ml.h-1 per catheter. Six patients (12%) required intravenous morphine rescue in the first 48 h, with a median dose of 3 mg. Median pain scores remained consistently low and 14 patients (28%) received additional local anaesthetic boluses with effective relief. No major catheter-related complications or systemic local anaesthetic toxicity were observed. Continuous wound infusion with levobupivacaine 0.0625% after open abdominal surgery was feasible and associated with minimal opioid use. These findings provide preliminary evidence supporting the feasibility of an ultralow concentration regimen.