Effect of pretreatment with ketorolac on propofol injection pain

Background: Pain on injection is still a major problem with propofol. We performed this study to compare different doses of intravenous (i.v.) ketorolac with and without venous occlusion and its effect on the incidence and the severity of the pain after propofol injection. Methods: We conducted a prospective, randomized and double-blind study of 180 patients (20-60years of age.) scheduled to undergo elective surgery. Six groups of patients were generated: group A received normal saline (NS) 2ml i.v.; groups B, C, D received ketorolac 10mg in 2ml NS with venous occlusion (VO) and a subsequent propofol injection at either 30, 60 or 120s; groups E and F received ketorolac 15mg and 30mg in 2ml NS and propofol was injected after 60 s. The pain perception was assessed during injection of propofol in all patients. Result: The incidence of propofol-associated injection pain was for A: 46.7%; B: 43.4%; C: 23.3%; D:16.7%; E: 20%, and F: 10%. The incidence of pain following propofol injection was reduced by i.v. ketorolac 10mg with venous occlusion for 120s. Furthermore, i.v. ketorolac 15mg and 30mg but not 10mg following propofol injection after 60s without venous occlusion revealed significant pain reduction when compared to saline group. There was no difference in venous sequelae at 7 days postoperatively between the groups. Conclusion: Our results suggested that pretreatment with i.v. 15 and 30mg ketorolac reduces pain following propofol injection. Moreover, pretreatment with i.v. ketorolac 10mg with venous occlusion for 120s achieves the same pain relief effect.