Analgesia and antiemetic therapies Pain was assessed immediately on return to the recovery room and at 6, 12 and 24 h after the operation using a visual analogue scale (VAS; 0 = no pain to 10 = most severe pain). Analgesia was given as intravenous sodium ketorolac (30 mg every 8 hours) and intravenous tramadol infusion (50 mg) was used as a backup analgesic medication. The incidence of PONV was recorded immediately on return to the recovery room and at 6, 12 and 24 h after the operation, using a three point ordinal scale (0 = none, 1 = nausea, 2 = retching, 3 = vomiting). Nausea was defined as a subjectively unpleasant sensation associated with awareness of the urge to vomit, retching was defined as the labored, spasmodic, rhythmic contraction of the respiratory muscles without the expulsion of gastric contents, and vomiting was defined as the forceful expulsion of gastric contents from the mouth. Intravenous ondansetron (4-8 mg) was given for antiemetic treatment on demand.