AIM:To compare the effects of preemptive analgesia of parecoxib, butorphanol, and pethidine used in and after strabismus surgery, and explore an effective and safe method of analgesia for strabismus surgery.

METHODS: This was a prospective, randomized, double-blind, placebo-controlled study.After the ethic committee approval and written conformed consent were obtained, 80 ASA Ⅰ patients aged 18-50 years undergoing strabismus surgery under local anesthesia were randomly allocated to 4 groups(n=20 each): group P received intramuscular parecoxib(40mg), group B received intramuscular butorphanol(1mg), group D received intramuscular pethidine(50mg), and group N received intramuscular normal saline(2mL). All patients received the drug at 30 minutes before surgery. Basal heart rate(HR)and meananerial pressure(HAP)were recorded on the day before surgery. The intensity of pain was measured using(numeric rating scales)NRS(0-10, 0=no pain, 10=worst pain)and recorded during operation time(T₁). Meanwhile, culocardiacreflex(OCR), nausea and vomiting, and sweating were also recorded. NRS, nausea and vomiting were recorded at 2 hours(T₂), 4 hours(T₃), 8 hours(T₄)after operation.

RESULTS: The NRS scores at T₁ were significantly lower in groups P, B, and D than in group N. OCR, nausea and vomiting, and sweating at T₁ were not significantly different among the 4 groups. The nausea and vomiting were significantly higher in group D than in groups P, B, and N. The NRS scores at T₂ were not significantly different among the 4 groups. The NRS scores in groups D and N at T₃ were significantly higher than those at T₂. And the NRS scores at T₃ were significantly higher in group D and N than groups P and B. The nausea and vomiting were significantly higher in group D than in groups P, B, and N. The NRS, nausea and vomiting were not significantly different among the 4 groups. The NRS scores in groups P and B were not significantly different at T₂, T₃, and T₄.

CONCLUSION:Preemptive analgesia with 40mg of parecoxib for strabismus surgery under local anesthesia is effective intraoperatively and postoperatively, and can reduce the postoperative nausea and vomiting.