Abstract： Objective:To investigate the effect of parecoxib sodium combined with hydromorphone on postoperative analgesia and inflammatory response in patients with lower limb fracture.Methods:Ninety-eight patients with lower extremity fractures treated in the Ningguo People′s Hospital from January 2021 to June 2022 were selected and randomly divided into two groups according to the order of admission, 49 cases in each group. The control group was anesthetized with hydromorphone, while the observation group was anesthetized with parecoxib sodium on the basis of the control group. The scores of Visual Analogue scale (VAS), Ramsay Sedation Scale (RASS), Bruggrmann Comfort Scale (BCS) at differences time point were compared between the two groups; the levels of interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) at 6, 12, 24, 48 h after operation and the complications were compared. The relationship between pain degree, inflammatory factors and the complications were analyzed by Spearman correlation.Results:The scores of VAS, RASS at 6, 12, 24, 48 h after operation in the observation group were lower than those in the control group, and the score of BCS in the observation group was higher than that in the control group, there were statistical differences ( P<0.05). The levels of IL-6, CRP, TNF-α at 6, 12, 24, 48 h after operation in the observation group were lower than those in the control group, there were statistical differences ( P<0.05). The complication rate in the observation group was lower than that in the control group: 14.29%(7/49) vs. 32.65%(16/49), there was statistical difference ( P<0.05). The results of Spearman correlation showed that VAS score were positively correlated with incidence rate of nausea and vomiting, hypotension, dizziness and lethargy, and decreased heart rate ( r = 0.262, 0.205, 0.234, 0.354, P<0.05); RASS score was positively correlated with hypotension and decreased heart rate ( r = 0.240, 0.452, P<0.05); BCS score was positively correlated with nausea and vomiting and decreased heart rate ( r = 0.210, 0.267, P<0.05); CRP, TNF-α and IL-6 were positively correlated with nausea and vomiting and catheter retention time ( r = 0.221, 0.254, 0.201; 0.227, 0.321, 0.223, P<0.05); CRP was negatively correlated with lethargy and dizziness ( r = - 0.321, P<0.05). Conclusions:Parecoxib sodium combined with hydromorphone anesthesia can improve postoperative pain and comfort, reduce postoperative inflammatory reaction in patients with lower limb fracture, and has high safety.