Heart rate , mean arterial pressure ( MAP ) , hemoglobin oxygen saturation ( SpO@ ) , respiratory rate , tidal volume ( VT ) and pressure of end-tidal carbon dioxide ( PETCO@ ) were recorded at the time before induction ( T@ ) , @ min before the end of surgery ( T@ ) , @ min before the end of surgery ( T@ ) , @ min before the end of surgery ( T@ ) , @ min before the end of surgery ( T@ ) , the end of surgery ( T@ ) , extubation ( T@ ) , @ min after transferal into post-anesthesia care unit ( PACU ) ( T@ ) , @ h after surgery ( T@ ) , extubation time , length of PACU stay , fentanyl consumption and adverse events were all recorded .