Camorcia M, Capogna G, Celleno D
Dipartimento di Anestesia e Rianimazione AFaR, CRCCS, Ospedale Fatebenefratelli, Rome, Italy.
Minerva Anestesiol. 2001 Sep;67(9 Suppl 1):29-32.
The aim of this study was to determine the ED50 for the dose of levobupivacaine 0,5% that, if given intrathecally will not cause total spinal anesthesia but will give a reliable and reproducible clinical sign to differentiate intrathecal from epidural injection.
Thirty women at term undergoing elective cesarean section under a combined spinal-epidural technique (CSE) were enrolled into this sequential allocation study. The dose in each test dose was determined by the response of the previous patient to the higher or lower dose in her test syringe, according to up-down sequential allocation. The exception to this was the first woman in each group, for whom the starting dose was chosen to be 4 mg. The end point was the occurrence of any motor block, in any side, within 5 minutes from intrathecal injection of the test dose. Test dose efficacy was assessed using a modified Bromage scale every minute for 5 minutes. The median effective dose of levobupivacaine was estimated from the up-down sequences using the formula of Dixon and Massey.
The MAD of the test dose for levobupivacaine was of 4,8 mg (4,4 to 5,2; 95% C.I.).
This study may help to determine the appropriate dose for a test dose for inadvertent spinal levobupivacaine.
本研究的目的是确定0.5%左旋布比卡因鞘内注射时的半数有效剂量（ED50），该剂量不会导致全脊髓麻醉，但能提供可靠且可重复的临床体征以区分鞘内注射与硬膜外注射。
30名足月择期剖宫产的女性接受腰麻 - 硬膜外联合技术（CSE），被纳入本序贯分配研究。根据上下序贯分配法，每个试验剂量由前一名患者对其试验注射器中较高或较低剂量的反应来确定。每组的第一名女性除外，其起始剂量选择为4mg。终点是鞘内注射试验剂量后5分钟内任何一侧出现运动阻滞。使用改良的 Bromage 量表每分钟评估一次试验剂量的效果，共评估5分钟。根据 Dixon 和 Massey 的公式从上下序列中估计左旋布比卡因的中位有效剂量。
左旋布比卡因试验剂量的平均绝对差（MAD）为4.8mg（4.4至5.2；95%置信区间）。
本研究可能有助于确定用于意外鞘内注射左旋布比卡因试验剂量的合适剂量。
