不同容量罗哌卡因用于超声引导下骶管阻滞的最低有效浓度（MEC95）：一项剂量探索研究。
The Minimum Effective Concentration (MEC95) of different volumes of ropivacaine for ultrasound-guided caudal epidural block: a dose-finding study.
机构信息
Department of Anesthesiology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, China.
Department of Anesthesiology, The Sixth Clinical Medical College of Xinjiang Medical University, Urumqi, Xinjiang, China.
出版信息
BMC Anesthesiol. 2023 Mar 9;23(1):74. doi: 10.1186/s12871-023-02026-y.
BACKGROUND
Caudal epidural block (CEB) may be beneficial in anorectal surgery because its use may extend postoperative analgesia. This dose-finding study aimed to estimate the minimum effective anesthetic concentrations for 95% patients(MEC95) of 20 ml or 25 ml of ropivacaine in with CEB.
PATIENTS AND METHODS
In this double-blind, prospective study, the concentration of ropivacaine administered in 20 ml and 25 ml for ultrasound-guided CEB were determined using the sample up-and-down sequential allocation study design of binary response variables. The first participant was given 0.5% ropivacaine. Depending on whether a block was successful or unsuccessful, the concentration of local anesthesia was decreased or increased by 0.025% in the next patient. Every five minutes for 30 min, the sensory blockade using a pin-prick sensation at S3 dermatome compared to at T6 dermatome were evaluated every 5 min within 30 min. An effective CEB was defined as a a reduction of sensation at S3 dermatome and the existence of flaccid anal sphincter. Anesthesia was considered successful if the surgeon could perform the surgery without additional anesthesia. We determined the MEC50 using the Dixon and Massey up-and-down method and estimated the MEC95 using probit regression.
RESULTS
The concentration of ropivacaine administered in 20 ml for CEB ranged from 0.2% to 0.5%. Probit regression with a bias-corrected Morris 95% CI derived by bootstrapping showed an MEC50 and MEC 50 of ropivacaine for anorectal surgical anesthesia were 0.27% (95% CI, 0.24 to 0.31) and 0.36%(95% CI, 0.32 to 0.61). The concentration of ropivacaine administered in 25 ml for CEB ranged from 0.175 to 0.5. Probit regression with a bias-corrected Morris 95% CI derived by bootstrapping showed an MEC50 and MEC95 for CEB were 0.24% (95% CI, 0.19 to 0.27) and 0.32% (95% CI, 0.28 to 0.54).
CONCLUSION
With ultrasound-guided CEB, the MEC95 of 0.36% ropivacaine at 20 ml and 0.32% ropivacaine at 25 ml provide adequate surgical anesthesia/analgesia 95% of patients undergoing anorectoal surgery.
TRIAL REGISTRATION
Clinicaltrails.gov: Retrospectively registered (ChiCTR2100042954; Registration date:1/2, 2021).
背景
骶管阻滞（CEB）在肛门直肠手术中可能是有益的，因为它的使用可以延长术后镇痛。本剂量探索研究旨在估计 20ml 或 25ml 罗哌卡因用于 CEB 的 95%患者的最小有效麻醉浓度（MEC95）。
患者和方法
在这项双盲、前瞻性研究中，使用二进制反应变量的样本上下序贯分配研究设计来确定用于超声引导的 CEB 的罗哌卡因的浓度。第一个参与者给予 0.5%罗哌卡因。根据阻滞是否成功，下一个患者的局部麻醉浓度将降低或增加 0.025%。在 30 分钟内的每 5 分钟内，评估 30 分钟内每 5 分钟 S3 皮节的针刺痛觉与 T6 皮节的针刺痛觉之间的感觉阻滞情况。有效的 CEB 定义为 S3 皮节感觉减弱和肛门括约肌松弛。如果外科医生能够在不增加麻醉的情况下进行手术，则认为麻醉成功。我们使用 Dixon 和 Massey 上下法确定 MEC50，并使用概率回归法估计 MEC95。
结果
用于 CEB 的 20ml 罗哌卡因浓度范围为 0.2%至 0.5%。通过 bootstrap 获得的具有偏倚校正的 Morris 95%置信区间的概率回归显示，用于肛门直肠手术麻醉的罗哌卡因 MEC50 和 MEC50 分别为 0.27%（95%CI，0.24 至 0.31）和 0.36%（95%CI，0.32 至 0.61）。用于 CEB 的 25ml 罗哌卡因浓度范围为 0.175 至 0.5。通过 bootstrap 获得的具有偏倚校正的 Morris 95%置信区间的概率回归显示，CEB 的 MEC50 和 MEC95 分别为 0.24%（95%CI，0.19 至 0.27）和 0.32%（95%CI，0.28 至 0.54）。
结论
在超声引导的 CEB 下，20ml 罗哌卡因的 MEC95 为 0.36%，25ml 罗哌卡因的 MEC95 为 0.32%，可提供 95%接受肛门直肠手术的患者的充分手术麻醉/镇痛。
试验注册
Clinicaltrails.gov：回顾性注册（ChiCTR2100042954；注册日期：2021 年 1 月 2 日）。
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