A Multicenter, Randomized, Open-Label, Parallel-Group Trial to Compare the Efficacy and Safety of the Sufentanil NanoTab PCA System/15 mcg (Zalviso™)to Intravenous Patient-Controlled Analgesia With Morphine for the Treatment of Acute Post-Operative Pain

Inclusion Criteria: * Male or female patients who are 18 years or older * Patients who are scheduled to undergo an open abdominal surgery (including laparoscopic-assisted), total knee or total hip replacement surgery under general anesthesia or spinal anesthesia that does not include intrathecal opioids during the operation. * Post-surgical patients who have been admitted to the PACU and are expected to remain hospitalized and to have acute post-operative pain requiring parenteral opioids for at least 48 hours after surgery. Exclusion Criteria: * Patients who have taken an opioid for more than 30 consecutive days, at a daily dose of more than 15 mg of morphine (or equivalent), within the past 3 months prior to surgery (e.g. more than 3 doses per day of Vicodin®, Norco®, Lortab® with 5 mg hydrocodone per tablet). * Patients with an allergy or hypersensitivity to opioids * Female patients who are pregnant or breast-feeding