Continuous Preperitoneal Infusion of Ropivacaine After Open Liver Resection: Effect on Post-operative Recovery and Morbidity. (ROPIHEP)

This study is a prospective, double blind, randomized study. Subjects will be randomized using a computer-generated table of random numbers into 2 groups. The patients scheduled to undergo open liver resection will be randomly allocated to receive a continuous wound infusion of either 0.2% ropivacaine (ropivacaine group A) or 0.9% saline (control group B). The patients will be thereafter randomly assigned to receive through the catheter either 0.2% ropivacaine (study group) (10-ml bolus followed by an infusion of 10 ml/h during 48 h) or the same protocol with 0.9% NaCl (control group), thanks to a elastomeric pump (500ml), set to deliver a 10-ml/h connected with the catheter. In addition, all patients will receive patient-controlled intravenous morphine analgesia. The primary endpoint : the opioid-related symptom distress scale (SDS) will be performed at 48 hours after surgery. Secondary endpoints will be pain intensity on a visual analog scale at rest, and on coughing, morphine consumption, respiratory dysfunction, transit recovery and side effects at 48 hours, 5 days after surgery.