ABSTRACT
PURPOSE: To determine the 90% effective dose (ED90) of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia (CSE) in parturients with super obesity (body mass index [BMI] ≥ 50 kg·m-2). METHODS: We enrolled parturients with BMI ≥ 50 kg·m-2 with term, singleton vertex pregnancies undergoing elective Cesarean delivery under CSE. An independent statistician generated the 0.75% hyperbaric bupivacaine dosing regimen in increments of 0.75 mg using a biased-coin up-down sequential allocation technique. This was combined with 15 µg fentanyl, 150 µg morphine, and normal saline to a volume of 2.05 mL. The initial and maximum doses were 9.75 mg and 12 mg, respectively. Participants, clinical team, and outcome assessors were blinded to the dose. The primary outcome was block success, defined as T6 block to pinprick within ten minutes and no intraoperative analgesic supplementation within 90 min of spinal injection. We determined the ED90 using logistic regression. RESULTS: We enrolled 45 parturients and included 42 in the analysis. All doses achieved a T6 level within ten minutes, and the primary outcome occurred in 0/1 (0%) of the 9.75-mg doses, 2/3 (67%) of the 10.5-mg doses, 21/27 (78%) of the 11.25-mg doses, and 11/11 (100%) of the 12-mg doses. The ED90 of hyperbaric bupivacaine was 11.56 mg (95% confidence interval, 11.16 to 11.99). Four parturients (9.5%) had sensory level higher than T2, but none was symptomatic or required general anesthesia. CONCLUSION: The estimated ED90 of hyperbaric bupivacaine with fentanyl and morphine in parturients with super obesity undergoing Cesarean delivery under CSE was approximately 11.5 mg. STUDY REGISTRATION: ClinicalTrials.gov (NCT03781388); first submitted 18 December 2018.
RéSUMé: OBJECTIF: Notre objectif était de déterminer la dose efficace à 90 % (DE90) de bupivacaïne hyperbare intrathécale pour l'accouchement par césarienne sous péri-rachianesthésie combinée (PRC) chez les personnes parturientes atteintes de super obésité (indice de masse corporelle [IMC] ≥ 50 kg·m−2). MéTHODE: Nous avons recruté des personnes parturientes ayant un IMC ≥ 50 kg·m−2 présentant des grossesses uniques à terme, en présentation céphalique et bénéficiant d'un accouchement par césarienne programmée sous PRC. Un·e statisticien·ne indépendant·e a généré le schéma posologique de bupivacaïne hyperbare à 0,75 % par incréments de 0,75 mg à l'aide d'une technique d'allocation séquentielle en escalier. La bupivacaïne a été combinée à 15 µg de fentanyl, 150 µg de morphine et à une solution physiologique salée jusqu'à un volume de 2,05 mL. Les doses initiale et maximale étaient respectivement de 9,75 mg et 12 mg. Les participant·es, l'équipe clinique et les personnes évaluant les résultats n'avaient pas connaissance de la dose. Le critère d'évaluation principal était la réussite du bloc, définie comme un bloc à T6 à la piqûre dans les dix minutes et aucune supplémentation analgésique peropératoire dans les 90 minutes suivant l'injection rachidienne. Nous avons déterminé la DE90 à l'aide d'une méthode de régression logistique. RéSULTATS: Nous avons recruté 45 personnes parturientes et en avons inclus 42 dans l'analyse. Toutes les doses ont atteint le niveau T6 en dix minutes, et le critère d'évaluation principal a été obtenu pour 0/1 (0 %) des doses de 9,75 mg, 2/3 (67 %) des doses de 10,5 mg, 21/27 (78 %) des doses de 11,25 mg et 11/11 (100 %) des doses de 12 mg. La DE90 de bupivacaïne hyperbare était de 11,56 mg (intervalle de confiance à 95 %, 11,16 à 11,99). Quatre personnes parturientes (9,5 %) ont affiché un niveau sensoriel supérieur à T2, mais aucune n'était symptomatique ni n'a nécessité d'anesthésie générale. CONCLUSION: La DE90 estimée de bupivacaïne hyperbare avec fentanyl et morphine chez les personnes parturientes hyperobèses bénéficiant d'une césarienne sous PRC était d'environ 11,5 mg. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT03781388); soumis pour la première fois le 18 décembre 2018.
Subject(s)
Anesthesia, Epidural , Anesthesia, Obstetrical , Anesthesia, Spinal , Female , Humans , Pregnancy , Anesthesia, Obstetrical/methods , Anesthetics, Local , Bupivacaine , Double-Blind Method , Fentanyl , Morphine , ObesityABSTRACT
OBJECTIVE: To evaluate the efficacy of wound infusion with ropivacaine plus ketorolac compared with placebo for post-cesarean delivery analgesia in women who received a multimodal analgesic regimen including intrathecal morphine. METHODS: In a randomized double-blind study, women undergoing scheduled cesarean delivery under spinal or combined spinal epidural anesthesia were randomized to wound infusion with ropivacaine 0.2% plus ketorolac, or saline placebo using an elastometric pump for 48 hours. The primary outcome was pain score with movement at 24 hours after surgery (0-10 scale, 0=no pain and 10=worst possible pain). Secondary outcomes included pain scores at rest at 24 hours, pain scores at rest and with movement at 2 and 48 hours, opioid consumption, and time to first rescue analgesic. A sample size of 35 per group (n=70) was planned. RESULTS: From November 8, 2016, to May 17, 2019, 247 women were screened, and 71 completed the study per protocol: 38 in the placebo group and 33 in the ropivacaine plus ketorolac group. Patient demographics and intraoperative characteristics were comparable between the groups. There was no significant difference between the groups in the primary outcome of pain score with movement at 24 hours (difference in median score 0, 95% CI -1 to 2, P=.94). There were also no significant differences between the placebo and ropivacaine plus ketorolac groups in pain scores at other time points, in total opioid consumption (difference in median consumption -12.5 mg, 95% CI -30 to 5, P=.11), or in time to rescue analgesics (median [interquartile range] 660 [9-1,496] vs 954 [244-1,710] minutes, hazard ratio 0.69, 95% CI 0.41 to 1.17, P=.16). CONCLUSION: There was no benefit of wound infusion with ropivacaine and ketorolac in women who received intrathecal morphine and a multimodal analgesic regimen. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02829944. FUNDING SOURCE: The study was supported in part by Avanos Medical Inc.
