Objectives: To determine the incidence of ipsilateral shoulder pain (ISP) with the therapeutic use of parecoxib compared with a placebo after thoracotomy.

Design: A prospective, randomized, double-blind, placebo-controlled trial.

Setting: A tertiary-care university hospital.

Participants: Adult patients undergoing an elective thoracotomy between June 2011 and February 2015.

Interventions: Patients were allocated randomly into the parecoxib group (n = 80) and the control group (n = 80). In the parecoxib group, 40 mg of parecoxib was diluted into 2 mL and given intravenously 30 minutes before surgery and then every 12 hours postoperatively for 48 hours. In the control group, 2 mL of normal saline was given to the patients at the same intervals.

Measurements and Main Results: A numerical rating scale was used to assess the intensity of ISP at 2, 6, 12, 24, 48, 72, and 96 hours after surgery. Intravenous morphine (0.05 mg/kg) was used as the rescue medication for ISP during the 96-hour period. Baseline characteristics of patients in both groups were comparable. Patients in the parecoxib group had a significantly lower incidence of ISP, both overall (42.5% v 62.0%, p = 0.014) and of moderate-to-severe ISP when compared with the control group (26.2% v 49.4%, p = 0.003). Parecoxib reduced the risk of ISP by a statistically significant 32% (risk ratio, 0.68; 95% confidence interval, 0.50-0.93, p = 0.016). There were no significant differences in the occurrence of adverse effects between the groups.

Conclusions: Intravenous parecoxib significantly can reduce the incidence and severity of ISP after thoracotomy.