The Efficacy of Different Ropivacaine Concentrations (0.5%, 0.6%, vs . 0.75%) for Regional Nerve Block in Lower Extremity: A Prospective Randomized Controlled Trial / 대한정형외과학회잡지

ABSTRACT

PURPOSE: There have only been a few studies on optimal usage of injection material in the regional nerve block for lower extremity operations. The purpose of this study was to evaluate the efficacy of different concentrations of ropivacaine. MATERIALS AND METHODS: A total of 339 patients underwent lower extremity surgery under ultrasound-guided nerve block (combined femoral and sciatic nerve block) at a Chungnam National University Hospital between March 2016 and February 2017 and were randomly assigned to three groups Group A (0.5%, 44 ml), group B (0.6%, 30 ml), and group C (0.75%, 30 ml). The interval between nerve block procedure and onset of the complete anesthetic effect (complete anesthetic time) was investigated. The degrees of intraoperative pain, and postoperative pain were evaluated using a visual analogue scale (VAS) score. Patient's satisfaction (0–10) was investigated. To evaluate the efficacy in accordance with the concentration under the same dose and same volume, group A and B were compared with group C respectively. RESULTS: There were 108, 118, and 113, in groups A, B, and C, respectively; and there were no significant differences with respect to the number, age, sex, and type of operation (p>0.05). The mean complete anesthetic times were 78.5, 76.4, and 58.6 minutes, respectively. The mean intraoperative VAS scores were 2.04, 0.62, and 0.24; and the mean postoperative VAS scores (6 hours/12 hours) were 2.41/4.08, 0.27/1.24, and 0.38/1.54. The mean patient's satisfactory scores were 8.53, 9.38, and 9.40, respectively. Compared with group C, group A showed significantly longer complete anesthetic time (p 0.05). Patient's satisfactory scores in both group A and B were similar to group C (p>0.05, p>0.05). There were no specific adverse reactions in all groups. CONCLUSION: Ropivacaine 0.6% as well as 0.75% are safe and effective anesthetics under the same volume (30 ml) for regional nerve block of the lower extremity. However, taking into account of the longer complete anesthetic time, the operation start time must be adjusted.