- All patients : patients will receive, through the interscalene catheter, a continuous infusion of bupivacaine 0,15% at the rate of 5 mL/h for at least 24 hours post-operatively After surgery, pain will be assessed using a verbal numeric pain scale. Patients will be asked to fill out a pain intensity measurement form using a 0-10 pain scale at 3, 6 and 24 hours after surgery.