Bupivacaine 0.5% versus ropivacaine 0.75% wound infiltration to decrease postoperative pain in total thyroidectomy, a prospective controlled study

Aim. Control of postoperative pain is one of the most important concerns for both the patients and the surgical team. In this regard the efficacy of wound infiltration with local analgesia and the most proper drugs to be used are not settled. We conducted our study trying to investigate this point in a prospective randomized double blinded manner. Methods. With inclusion criteria of: age (18-65 y), volume <90 mL, first time, no lymph node enlargement and exclusion criteria of: duration >90 min, incision length >10 cm, neck dissection decided during surgery and a postoperative complication within the first 24 hours. Sixty patients planned for total thyroidectomy under general anesthesia were enrolled in the study in three groups with twenty patients assigned randomly to each one: group (A) a control group in which no wound infiltration was done group (B) in which preoperative wound infiltration with 10 mL bupivacaine 0.5% was done, and group (C) in which preoperative wound infiltration with 10 mL ropivacaine 0.75% was done. Postoperative pain was evaluated by Visual Analogue Score (VAS) with a scale of (0-10) at 1 hour, 4 hours, 8 hours and 16 hours. Results. The postoperative pain experienced by all the patients reached a maximum point at 1 hour postoperatively then started to decrease to be minimal at 8 hours and almost negligible at 16 hours. Ropivacaine group showed a statistically significant decrease in pain perception at 1 hour postoperatively (P=0.028), bupivacaine group showed also a decrease in pain perception at 1 hour but it was not statistically significant. At 4 hours of operation and after; neither ropivacaine nor bupivacaine showed an effect on pain perception. Conclusion. The benefit of local wound infiltration with local analgesia in decreasing postoperative pain is limited to a short period after surgery in which the use of ropivacaine 0.75% is recommended over pubivaccaine 0.5%.