罗哌卡因用于超声引导下肛门直肠手术骶管阻滞的最低有效浓度（MEC90）。一项剂量探索研究。
The minimum effective concentration (MEC90) of ropivacaine for ultrasound-guided caudal block in anorectal surgery. A dose finding study.
机构信息
Department of Anesthesiology, and Laboratory of Anesthesia and Intensive Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China.
Division of Biostatistics & Epidemiology, School of Public Health, San Diego State University, San Diego, CA, United States of America.
出版信息
PLoS One. 2021 Sep 17;16(9):e0257283. doi: 10.1371/journal.pone.0257283. eCollection 2021.
BACKGROUND
Caudal epidural block (CEB) provides reliable anesthesia for adults undergoing anorectal surgery. Despite the widely utilization, the minimum effective concentration for 90% patients (MEC90) of ropivacaine for CEB remains unknown.
OBJECTIVE
To estimate MEC of ropivacaine for CEB in anorectal surgery.
DESIGN
A prospective dose-finding study using biased coin design up-and-down sequential method.
SETTING
Operating room and postoperative recovery area of Chengdu Shangjin Nanfu Hospital, from October 2019 to January 2020.
PATIENTS
50 males and 51 females scheduled for anorectal surgery.
INTERVENTIONS
We conducted two independent biased coin design up-and down trials by genders. The concentration of ropivacaine administered to the first patient of male and female were 0.25% with fixed volume of 14ml for male and 12ml for female patients based on our previous study. In case of failure, the concentration was increased by 0.05% in the next subject. Otherwise, the next subject was randomized to a concentration 0.05% less with a probability of 0.11, or the same concentration with a probability of 0.89. Success was defined as complete sensory blockade of perineal area 15 min after the block evidenced by the presence of a lax anal sphincter and pain-free surgery.
MAIN OUTCOME MEASURES
The MEC of ropivacaine to achieve a successful CEB in 90%(MEC90) of the patients.
RESULTS
The MEC90 of ropivacaine for CEB were estimated to be 0.35% (95% CI 0.29 to 0.4%) for male and 0.353% (95%CI 0.22 to 0.4%) for female. By extrapolation to MEC in 99% of subjects (MEC99) and pooled adjacent violators algorithm (PAVA) adjusted responses, it would be optimal to choose 0.4% ropivacaine with a volume of 14ml for male and 12ml for female.
CONCLUSIONS
A concentration of 0.35% ropivacaine with a volume of 14ml provided a successful CEB in 90% of the male patients, while 0.353% ropivacaine with a volume of 12ml provided a successful CEB in 90% of the female patients. A concentration of 0.4% and a volume of 14ml for male and 12 ml for female would be successful in 99% of the patients.
TRIAL REGISTRATION
Chictr.org.cn identifier: No. ChiCTR 1900024315.
背景
骶管阻滞（CEB）可为接受肛门直肠手术的成人提供可靠的麻醉。尽管广泛应用，但罗哌卡因用于 CEB 的 90%患者的最小有效浓度（MEC90）仍不清楚。
目的
估计罗哌卡因用于肛门直肠手术的 CEB 的 MEC。
设计
使用偏倚硬币设计上下序贯法的前瞻性剂量发现研究。
地点
成都上锦南府医院手术室和术后恢复区，2019 年 10 月至 2020 年 1 月。
患者
50 名男性和 51 名女性，计划接受肛门直肠手术。
干预措施
我们按性别进行了两项独立的偏倚硬币设计上下试验。根据我们之前的研究，第一例男性和女性患者的罗哌卡因浓度分别为 0.25%，固定体积为男性 14ml，女性 12ml。如果失败，则在下一个受试者中增加 0.05%的浓度。否则，下一个受试者以 0.11 的概率随机分配到浓度降低 0.05%，或以 0.89 的概率分配到相同浓度。成功定义为阻滞 15 分钟后，会阴部区域完全感觉阻滞，表现为肛门括约肌松弛和手术无痛。
主要观察指标
90%（MEC90）患者实现成功 CEB 的罗哌卡因 MEC。
结果
男性的 CEB 罗哌卡因 MEC90 估计为 0.35%（95%CI 0.29 至 0.4%），女性为 0.353%（95%CI 0.22 至 0.4%）。通过外推到 99%的受试者的 MEC（MEC99）和合并相邻违规者算法（PAVA）调整的反应，选择 0.4%罗哌卡因和 14ml 男性体积，12ml 女性体积是最佳选择。
结论
14ml 体积的 0.35%罗哌卡因在 90%的男性患者中提供了成功的 CEB，而 12ml 体积的 0.353%罗哌卡因在 90%的女性患者中提供了成功的 CEB。男性 14ml 和女性 12ml 体积的 0.4%浓度将使 99%的患者获得成功。
试验注册
Chictr.org.cn 标识符：No. ChiCTR 1900024315。
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