Shivering is an early postoperative complication during the postoperative recovery period, and there is no clear consensus about the best way for its prevention. The aim of the study was to compare the efficacy and accompanying side effects of prophylactic flurbiprofen with that of parecoxib or placebo for reducing postoperative shivering.

154 patients with American Society of Anesthesiologists physical status I-II, who were scheduled for colorectal operation under general anesthesia, were randomly assigned to receive flurbiprofen (Group F), parecoxib sodium (Group P ) or normal saline(Group S)40min before the end of surgery. Hemodynamic parameters were monitored. The occurrence of shivering postoperative nausea and vomiting were recorded during the recovery period. And visual analogue score (VAS) and ramsy sedation scale (RSS) were also recorded.

Inclusion Criteria:

• One hundred and sixty-six, American Society of Anesthesiologists' (ASA) physical status1or2, patients, undergoing colorectal operation were selected in the prospective, randomized, double-blind clinical study.
• All patients who were from 21 to 62 years old and body mass index 19-35 in tumor hospital of Guangxi medical university (State of China) from April 2014 to April 2015 were included.

Exclusion Criteria:

• Patients with cardiac, pulmonary, hepatic, renal, thyroid, or neuromuscular disease, and those who took chronic drug or abused alcohol were excluded.
• Another patients with hypertension, gastrointestinal bleeding, an initial core temperature >37.5℃ or <36.5℃, a history of allergy to non- steroidal anti-inflammatory drugs (NSAIDs) or other agents to be used, and inability to cooperate were also excluded in this study.
• Another patients with blood loss during operation>400ml, a need for blood transfusion during surgery, duration of operation>4h and surgical procedures changed were excluded.