Postoperative pain was controlled for all patients routinely by intravenous sulfentanil patient-controlled analgesia (PICA) in combination with Parecoxib (40 mg, every 12 h), a selective COX-2 inhibiter. PICA was continued with sulfentanil (0.9µg.h-1) and 0.9 µg sulfentanil bolus with a 8-min lockout time. Oral oxycodone 0.2 mg was administered necessarily.