Local anesthetics are often given in a continuous fashion to block specific nerves after an operation for pain control. A new infusion strategy named the 'programmed intermittent bolus' (PIB) technique delivers the hourly dose within minutes compared to the traditional infusion that delivers such dose over an hour. The PIB technique has demonstrated superior patient satisfaction and reduced local anesthetic consumption when utilized for pain control during labour and delivery. However, it is not known if the PIB technique gives any benefits during a continuous nerve block in other settings. The aim of this randomized controlled trial (RCT) is to elucidate if PIB is better than (traditional) continuous infusion for postoperative analgesia in patients receiving a continuous nerve block for total shoulder arthroplasty with respect to pain control.