Propofol and sevoflurane have different effects on heart rate variability. It has not yet been reported whether this difference in effect remains at recovery time after anesthesia and the difference is related to postoperative nausea and vomiting has not been studied. The aim of this study is observe whether propofol and sevoflurane have different effects on heart rate variability during recovery and the differences can predict the occurrence of postoperative nausea and vomiting.

Different types of anesthetics have different effects on heart rate variability. However It has not yet been reported whether this difference in effect remains at recovery time after anesthesia.

Several studies have been reported that preoperative heart rate variability predicted the occurence of postoperative nausea and vomiting. However, whether the difference in heart rate variability after anesthesia is related to the difference in postoperative nausea and vomiting has not been studied. Therefore, this study aims to observe whether propofol and sevoflurane have differences during recovery period after anesthesia in heart rate variabiliy. In addition, we want to examine that these differences during recovery period in heart rate variability can predict the occurrence of nausea and vomiting within 24 hours after surgery.

Inclusion Criteria:

• Scheduled breast surgery under general anesthesia

Exclusion Criteria:

• Arrhythmia
• Uncooperative with the measuring heart rate variability
• Diabetes
• Hypertension on medication
• Patients taking psychiatric drugs
• Thyroid disease

Include only mathces self-representation of gender identity and biological sex

20~50 years old female patients who scheduled breast surgery under general anesthesia

We will provide it upon the reasonable personal request.