Comparison of efficacy of different doses of ropivacaine for ultrasound-guided axillary brachial plexus block in children

Abstract

Objective To compare the efficacy of different doses of ropivacaine for ultrasound-guided axillary brachial plexus block in children.Methods One hundred and twenty ASA Ⅰ or Ⅱ children,aged 5-12 yr,scheduled for elective surgery for hand injury,were equally and randomly divided into 4 groups according to the doses of ropivacaine:0.35,0.3,0.25 and 0.20 ml/kg groups.The children received oral midazolam 30 min before surgery.Propofol was given by target-control infusion after admission to the operating room.When the pediatric patients lost consciousness and had no response to verbal command,axillary brachial plexus block was performed under the guidance of ultrasound.0.25 ％ ropivacaine 0.35,0.3,0.25 and 0.20 ml/kg were injected to block the radial,median,ulnar,musculocutaneous and medial antebrachial cutaneous nerves.Additional ketamine was given when needed during operation.The duration of block and consumption of general anesthesia and complications were recorded.The degree of sensory block of the region innervated by each nerve and effectiveness of block were assessed.Results The rate of effective block of the radial nerve,median nerve and musculocutaneous nerve was significantly lower,the number of patients requiring ketamine was larger and the duration of block was shorter in group 0.2 ml/kg than in 0.35,0.30 and 0.25 ml/kg groups (P ＜ 0.05).There was no significant difference in the parameters mentioned above between 0.35,0.30 and 0.25 ml/kg groups (P ＞ 0.05).No pediatric patients developed block-related complications in each group.Conclusion Ultrasound-guided axillary brachial plexus block with 0.25 ％ ropivacaine 0.25 ml/kg can provide better block in children. Key words: Uhrasonography; Brachial plexus; Nerve block ; Children; Anesthetics,local