重比重罗哌卡因腰麻用于单胎或双胎剖宫产的剂量-反应研究

研究目的：单胎妊娠与多胎妊娠剖宫产腰麻的局部麻醉剂量要求是否存在差异尚有争议。本研究的目的是测定和比较重比重罗哌卡因用于单胎妊娠和双胎妊娠剖宫产腰麻的ED₅₀和ED₉₀。

受试者：100例单胎妊娠(S组)和100例双胎妊娠(T组)且在腰麻-硬膜外联合麻醉下择期行剖宫产的产妇。

干预措施：将S组和T组患者随机分为5组，分别鞘内注射9.5、11、12.5、14、15.5 mg重比重罗哌卡因。如鞘内注射后10分钟内达到T6及以上双侧皮肤感觉阻滞，术中数字评分法(NRS)评估疼痛未出现评分≥3，并且麻醉和手术期间无需硬膜外追加药物则被认为是有效剂量。使用Probit回归模型计算罗哌卡因的ED₅₀和ED₉₀值。通过计算相对中位数效力来评估单胎妊娠患者和双胎妊娠患者之间罗哌卡因剂量需求的差异。

测量指标：记录鞘内注射不同剂量罗哌卡因的成功率、副作用和新生儿结局。

主要结果：单胎妊娠患者鞘内注射罗哌卡因的ED₅₀和ED₉₀的估计值(95%CI)分别为11.2(10.2~12.0) mg和15.7(14.4~18.3) mg。双胎妊娠组ED₅₀为10.5(9.5~11.3) mg，ED₉₀值为14.8 mg (13.6~17.0) mg。罗哌卡因在单胎妊娠和双胎妊娠患者之间的相对中位数效力估计值为0.94(95%CI为0.83~1.04)。

结论：单胎妊娠和双胎妊娠患者在腰-硬膜外联合麻醉(CSE)、无阿片类药物使用、低体重队列、患者右侧卧位置入导管和去甲肾上腺素使用的情况下，用于剖宫产腰麻的重比重罗哌卡因的剂量需求相似。

原始文献来源：Mei Z, Ngan Kee WD, Sheng ZM, et al. Comparative dose-response study of hyperbaric ropivacaine for spinal anesthesia for cesarean delivery in singleton versus twin pregnancies.[J] .J Clin Anesth, 2020, 67: 110068.

Comparative dose-response study of hyperbaric ropivacaine for spinal anesthesia for cesarean delivery in singleton versus twin pregnancies

[Abstract]

Study objective: It is controversial whether local anesthetic dose requirement for spinal anesthesia for cesarean delivery differs between patients with singleton and patients with multiple gestation pregnancies. The aim of this study was to determine and compare the ED50 and ED90 for hyperbaric ropivacaine used for spinal anesthesia for cesarean delivery in patients with singleton pregnancies versus patients with twin pregnancies.

Design: Prospective, randomized, comparative dose-finding study.

Setting: Operating room, Women's Hospital, Zhejiang University School of Medicine.

Patients:100 patients with singleton pregnancies (Group S) and 100 patients with twin pregnancies (Group T) presenting for scheduled cesarean delivery under combined spinal-epidural anesthesia were enrolled in the study.

Interventions: Patients in Group S or Group T were randomly allocated to receive 9.5, 11, 12.5, 14 or 15.5 mg of hyperbaric ropivacaine intrathecally. A dose was considered effective when it achieved a bilateral sensory block level at the T6 dermatome or above within 10 min after intrathecal injection, there was no numerical rating scale (NRS) pain score ≥ 3 intraoperatively, and there was no requirement for epidural supplementation at any time during anesthesia and operation. Values for ED50 and ED90 for ropivacaine were determined using probit regression. The difference in ropivacaine dose requirement between patients with singleton pregnancies and patients with twin pregnancies was assessed by calculating relative median potency.

Measurements:Success rates for different intrathecal doses of ropivacaine, side effects and neonatal outcomes were recorded.

Main results: The estimated (95% confidence interval) values for ED50 and ED90 of intrathecal ropivacaine in patients with singleton pregnancies were 11.2 (10.2 to 12.0) mg and 15.7 (14.4 to 18.3) mg, respectively. The values for ED50 and ED90 in patients with twin pregnancies were 10.5 (9.5 to 11.3) mg and 14.8 mg (13.6 to 17.0) mg, respectively. The estimate of relative median potency for ropivacaine between patients with singleton and twin pregnancies was 0.94 (95% confidence interval 0.83 to 1.04).

Conclusion: Patients with singleton and twin pregnancies have similar dose requirement for hyperbaric ropivacaine used for spinal anesthesia for cesarean delivery in the setting of combined spinal-epidural (CSE) anesthesia, no opioids, low weight cohort, insertion with the patients in the right lateral position, and norepinephrine boluses.