Use of clonidine as an adjuvant to infiltration anaesthesia in tympanoplasty: a randomized double blind study

This prospective double blind randomized study evaluated the effect of clonidine when used as an adjuvant to local anaesthetic agents for infiltration block and measured its impact on the quality of anaesthesia, intraoperative bleeding and post-operative pain. We recruited 60 patients needing tympanoplasty, which were randomized them into two groups; group A patients received local infiltration of 12 ml 2 % xylocaine with adrenaline (1:200,000 dilution), while group B received 12 ml 2 % xylocaine with adrenaline with 30 μg of clonidine. Duration of block was significantly prolonged in group B (group A 53.66 ± 7.7 vs. group B 177.13 ± 48.9, p < 0.005). Mean pain scores were significantly lower in group B during the first hour following the block (3.43 in group A vs. 1.2 in group B, p < 0.005). Total number of analgesic doses over 24 h showed no significant difference (3.1 in group B vs. 3.26 in group A, p > 0.05). 93.3 % patients in group A required sedation with midazolam, compared to 10 % in group B. Grade of bleeding was significantly lower in group B. Patient and surgeon satisfaction scores were better in group B. It could be concluded that 30 μg clonidine added to lidocaine 2 % has a significant impact in decreasing the bleeding in the operative field and improving the quality of intraoperative anesthesia as well as prolonging the duration of postoperative analgesia without significant side effects.