Comparison of efficacy of different concentrations of ropivacaine for interscalene brachial plexus block in patients undergoing arthroscopic shoulder surgery under general anesthesia / 中华麻醉学杂志

ABSTRACT

Objective:To compare the efficacy of different concentrations of ropivacaine for interscalene brachial plexus block in patients undergoing arthroscopic shoulder surgery under general anesthesia.Methods:Ninety American Society of Anesthesiologists physical statusⅠor Ⅱ patients (NYHA classⅠorⅡ) of both sexes, aged 18-64 yr, with body mass index of 18.0-26.9 kg/m 2, undergoing elective arthroscopic shoulder surgery were selected, and were divided into 3 groups ( n=30 each) using a random number table method: 0.25% ropivacaine group (group A), 0.375% ropivacaine group (group B) and 0.5% ropivacaine group (group C). Interscalene brachial plexus block was performed with 0.25%, 0.375% and 0.5% ropivacaine 20 ml in A, B and C groups, respectively.Before operation (T 0) and at 30 min (T 1), 4 h (T 2), 6 h (T 3), 8 h (T 4), 10 h (T 5) and 12 h (T 6) after administration, the diaphragmatic mobility was measured and recorded using M-mode ultrasound and forced expiratory volume in the first second (FEV 1) and forced vital capacity (FVC) were measured using portable spirometer.The occurrence of phrenic paralysis was recorded at T 1-6.The duration of sensory and motor block was recorded.When visual analogue scale score>3 within 24 h after operation, flurbiprofen axetil 50 mg was injected intravenously for analgesia and the consumption was recorded.The adverse reactions such as cardiovascular events, local anesthetic intoxication, Horner syndrome, pneumothorax, and nausea and vomiting within 24 h after administration were recorded. Results:Compared with group A, the diaphragmatic mobility was significantly decreased during quiet breathing at T 1-3 and was decreased during deep breathing at T 2-5, and the diaphragmatic paralysis rate was increased during quiet and deep breathing at T 2-3 in group B, diaphragmatic mobility was decreased during quiet and deep breathing at T 1-6, diaphragmatic paralysis rate was increased during quiet and deep breathing at T 1-4, FEV 1% and FVC% were decreased at T 1 and FVC% was decreased at T 2 in group C, and the duration of sensory and motor block was prolonged in B and C groups ( P<0.05 or 0.01). Compared with group B, the diaphragmatic mobility was significantly decreased during quiet breathing at T 4-6 and was decreased during deep breathing at T 1-6, the diaphragmatic paralysis rate during quiet breathing was increased at T 2-4 ( P<0.05) was increased during deep breathing at T 3-4, and FEV 1 % and FVC % at T 1 were decreased in group C ( P<0.05). There was no significant difference in the postoperative requirement for flurbiprofen axetil and the incidence of adverse reactions within 24 h after administration among the 3 groups ( P>0.05). Conclusion:0.25% ropivacaine 20ml provides better efficacy when used for interscalene brachial plexus block in the patients undergoing arthroscopic shoulder surgery.