The words tijera and tijeras can be used interchangeably in Spanish to refer to a single pair of scissors.
Both IV sedation (twilight) and general anesthesia are used commonly for cosmetic or plastic surgery. Regardless of technique, the patient's vital signs must be monitored, which include but not limited to heart rate, blood pressure, and breathing rate.
Although the patient is under general anesthesia they are still breathing on their own and the airway is protected. With sedation all monitoring is the same as far as cardiac rhythm, blood pressure, oxygen saturation etc. However, the patient must be given enough sedation to sleep but continue to breath.