The purpose of this study is to study the efficacy of dexamethasone added to ramosetron for preventing postoperative nausea and vomiting in highly susceptible patients following spine surgery.

Inclusion Criteria:

• Females
• Ages 18 to 65 years old

Exclusion Criteria:

• Patients who is taking steroid or who had been treated for the gastrointestinal disease
• Patients who have troubles with the kidney or liver
• Patients transferring to the ICU after the surgery
• overfat patients
• Patients who had taken antiemetics within 24 hours before the surgery