Efficacy of continuous brachial plexus block guided by different methods: comparison of effectiveness, safety and comfort

Abstract

Objective To compare the effectiveness, safety and comfort of continuous brachial plexus block (BPB) guided by different methods. Methods A total of 189 patients of both sexes, of American Society of Anesthesiologists physical status Ⅰor Ⅱ, aged 18-64 yr, weighing 46-90 kg, undergoing elective internal fixation after elbow fracture under general anesthesia, were divided into 3 groups (n=63 each) using a random number table: ultrasound combined with nerve stimulator-guided axillary approach to continuous BPB group (group A), ultrasound combined with nerve stimulator-guided subclavian coracoid approach to continuous BPB group (group B) and ultrasound-guided subclavian coracoid approach to continuous BPB group (group C). Brachial plexus nerve block was performed with 0.2% ropivacaine 30 ml, and anesthesia was induced by IV injection of sufentanil 0.3 μg/kg, propofol 2-3 mg/kg and rocuronium 0.6 mg/kg after confirmation of satisfactory block using the acupuncture method in the three groups.Anesthesia was maintained by inhalation of 1.5%-2.5% sevoflurane and IV infusion of propofol 2-4 mg·kg-1·h-1.Patient-controlled nerve block analgesia was performed after removal of endotracheal tube at the end of surgery.Analgesia solution contained 0.2% ropivacaine which was diluted to 200 ml in normal saline.Parameter settings were adjusted with background infusion at rate 5 ml/h, 5 ml bolus dose and 60 min lockout interval.Analgesia lasted until 72 h after surgery, maintaining a visual analog scale score less than or equal to 3.When the visual analog scale score was more than 3, tramadol 100 mg was intramuscularly injected as a rescue analgesic.Comfort scores, requirement for rescue analgesic within 72 h after surgery, development of pneumothorax, local anesthetic intoxication and intravascular puncture during puncture operation and development of postoperative adverse reactions such as tube shedding, nausea and vomiting and nerve damage were recorded. Results Compared with group A, the comfort score was significantly increased, and the requirement for rescue analgesic was decreased in B and C groups (P 0.05). There was no significant difference in the incidence of adverse reactions between the three groups (P>0.05). Conclusion The effectiveness and comfort of subclavian coracoid approach to continuous BPB is better than those of axillary approach, and the comfort of subclavian coracoid approach to continuous BPB under only ultrasound guidance is superior to that under ultrasound combined with nerve stimulator guidance. Key words: Brachial plexus; Nerve block