Clonidine does not improve quality of ropivacaine axillary brachial plexus block in children

Summary Background:  The addition of clonidine to peripheral nerve blocks is controversial in children. Objective:  The aim of our study was to evaluate the effect of clonidine added to ropivacaine in pediatric axillary brachial plexus block (ABPB). Methods:  Children aged 1–6 years, scheduled to undergo forearm or hand surgery, were recruited into this prospective, double-blind controlled trial. Patients were randomly allocated to receive an ABPB either with ropivacaine 0.2% 0.4 ml·kg−1 plus saline in 1 ml (RS) or ropivacaine 0.2% 0.4 ml·kg−1 plus clonidine 1 μg·kg−1 in 1 ml (RC). Primary endpoints were quality of postoperative analgesia as assessed by pain scores and total 24-h postoperative analgesia requirements. Secondary outcomes were time to first analgesia request and duration of motor blockade. Results:  Sixty patients were recruited (n = 30 per group) into the study. Pain scores were comparable throughout the first 24 h between the two groups. Ten children in the (RS) and six in (RC) groups required supplementary analgesia during the first 24 h (P = 0.24). Children who required further analgesia did so after 288 ± 94 min in the (RS) and 437 ± 204 min in the (RC) group (P = 0.06). There was no difference in the duration of motor block [186 ± 71 and 154 ± 56 min, P = 0.12 for (RS) and (RC), respectively]. Conclusion:  Ropivacaine (0.2% 0.4 ml·kg−1) for ABPB provides sufficient postoperative analgesia in children scheduled for forearm or hand surgery. The addition of clonidine to ABPB does not improve overall postoperative analgesia but may increase the time to first analgesia request.