Primary outcomes and secondary outcomes

Primary outcomes included PONV and postoperative vomiting (PV). Patients with a history of nausea and vomiting as reported in medical records were determined as positive results. PONV was defined as nausea or vomiting occurring in any order within 24 h after surgery. The occurrence time of the first event was set as the occurrence time of PONV. PV was defined as vomiting occurring regardless of nausea within 24 h after surgery. The time to onset of vomiting was set as the time to onset of vomiting after surgery, regardless of whether or not there was nausea within 24 h after surgery. Secondary outcomes were intraoperative invasive monitoring and the use of vasopressors or inotropes during the operation or in the recovery room. To determine whether there was a difference between intraoperative monitoring and drug use due to differences in ASA-PS scores, monitoring via arterial catheterization, central venous pressure monitoring, indwelling urinary catheter, and intraoperative vasopressor or inotrope use were compared before and after propensity score matching.