This is a prospective, multi-site, anesthesiologist and PACU nurse TOF-Watch SX® blinded observational study of surgical patients undergoing elective laparoscopic or open abdominal procedures requiring general anesthesia and non-depolarizing neuromuscular blockade. There are two temporal aspects to the data collection: a prospective data collection in the OR and PACU; and a retrospective chart review one week after hospital discharge.