Rey Moura Ed Carlos, de Oliveira Caio Marcio Barros, da Cunha Leal Plinio, Kimiko Sakata Rioko
Universidade Federal de São Paulo, Department of Anesthesia, São Paulo, Brazil.
Universidade Federal do Maranhão, Department of Medicine, São Luiz, Maranhão, Brazil.
J Pain Res. 2021 Jan 13;14:53-59. doi: 10.2147/JPR.S282286. eCollection 2021.
After knee surgery, analgesia should be effective for mobilization and discharge.
The primary objective of this study was to achieve the lowest effective analgesic concentration (MEC50 and MEC90) of ropivacaine for saphenous nerve block in arthroscopic meniscectomy. The secondary objective was to determine whether the block causes muscle weakness in the postoperative period.
The study was randomized, comparative, and double-blind. Fifty-one patients between 18 and 65 years old of both sexes, ASA I or II, who underwent knee arthroscopic meniscectomy at São Domingos Hospital were included. Patients underwent saphenous nerve block with 10 mL of ropivacaine administered by using the up-and-down method. The ropivacaine concentration was determined based on the previous patient's response (a biased-coin up-down design sequential method). If a patient had a negative response, the concentration of ropivacaine was increased by 0.05% in the next patient; if the response was positive, the next patient was randomized to be administered the same concentration of ropivacaine or a 0.05% lower concentration. Successful block was defined as pain <4 during 6 h. Patients underwent general anesthesia with 30 µg/kg alfentanil and propofol and maintenance with propofol, and, if necessary, remifentanil was administered. Postoperative analgesia was complemented with dipyrone, and if necessary, tramadol (100 mg) could be used. The following parameters were assessed: the success of the block; pain intensity after 2, 4, and 6 h; the consumption of remifentanil; time to the first analgesic supplementation; percent of patients who needed analgesics during 6h; and muscle strength.
The MEC50 of ropivacaine was 0.36%, and the MEC90 was 0.477%. The block was successful in 45 patients.
Saphenous block with 10 mL of 0.36% ropivacaine provides adequate analgesia for outpatient meniscectomy.
膝关节手术后，镇痛应有效促进活动和出院。
本研究的主要目的是确定罗哌卡因用于关节镜半月板切除术隐神经阻滞的最低有效镇痛浓度（MEC50和MEC90）。次要目的是确定该阻滞在术后是否会导致肌肉无力。
本研究为随机、对照、双盲研究。纳入了51例年龄在18至65岁之间、性别不限、ASA分级为I或II级、在圣多明戈斯医院接受膝关节镜半月板切除术的患者。患者采用上下法接受10 mL罗哌卡因的隐神经阻滞。罗哌卡因浓度根据前一位患者的反应确定（偏倚硬币上下设计序贯法）。如果患者反应为阴性，则下一位患者的罗哌卡因浓度增加0.05%；如果反应为阳性，则下一位患者随机接受相同浓度的罗哌卡因或低0.05%的浓度。成功阻滞定义为6小时内疼痛<4分。患者接受30 μg/kg阿芬太尼和丙泊酚全身麻醉，并用丙泊酚维持麻醉，必要时给予瑞芬太尼。术后镇痛用安乃近补充，必要时可使用曲马多（100 mg）。评估以下参数：阻滞成功率；2、4和6小时后的疼痛强度；瑞芬太尼消耗量；首次补充镇痛药的时间；6小时内需要镇痛药的患者百分比；以及肌肉力量。
罗哌卡因的MEC50为0.36%，MEC90为0.477%。45例患者阻滞成功。
用10 mL 0.36%罗哌卡因进行隐神经阻滞可为门诊半月板切除术提供充分的镇痛。
