Fig. 1. Flow chart of randomization and follow-up. Isoflurane patients received inhalational anesthesia with isoflurane–nitrous oxide after induction with thiopental (inpatients) or propofol (outpatients); total intravenous anesthesia (TIVA) patients received total intravenous anesthesia with propofol–air for induction and maintenance. ICU = intensive care unit.