Department of Anesthesiology and Pain Medicine, Ajou University School of Medicine, Suwon, South Korea.
Eur Rev Med Pharmacol Sci. 2022 Mar;26(5):1632-1639. doi: 10.26355/eurrev_202203_28231.
The optimal remifentanil concentration for improving intubation conditions when intubation is performed without neuromuscular blocking agents (NMBAs) but with ketamine as an induction agent remains unknown. Here, we aimed to identify the effective bolus doses of remifentanil required to achieve acceptable intubation conditions upon anesthesia induction with 1 or 2 mg/kg ketamine without NMBAs.
In this prospective, double-blinded, randomized up-down sequential allocation study, we enrolled pediatric patients aged 3-12 years undergoing general anesthesia for inguinal hernia surgery. The patients were randomly allocated to one of two groups to receive either ketamine 1.0 mg/kg (K1 group) or 2.0 mg/kg (K2 group) intravenously until seven success-failure pairs were achieved. The remifentanil dose for each patient was determined using the modified Dixon's up-and-down method with an initial dose of 2.5 μg/kg and a step size of 0.5 μg/kg.
In total, 51 patients (22 in the K1 group and 29 in the K2 group) were enrolled. The effective dose (ED)50s of remifentanil for obtaining clinically acceptable intubation conditions under anesthesia induction with ketamine but without NMBAs was 3.2 μg/kg in the K1 group and 1.6 μg/kg in the K2 group. High-dose remifentanil with 1 mg/kg ketamine was associated with more severe chest wall rigidity and lower mean blood pressure and heart rate than was low-dose remifentanil with 2 mg/kg ketamine.
The ED50 of remifentanil required for clinically acceptable intubation conditions with anesthesia induction using 1 mg/kg ketamine without NMBAs in pediatric patients was twice that when using 2 mg/kg ketamine. The combination of 2 mg/kg ketamine and remifentanil was better at preventing chest wall rigidity.
在无神经肌肉阻滞剂（NMBAs）但使用氯胺酮作为诱导剂进行插管时，改善插管条件的瑞芬太尼最佳浓度尚不清楚。在此，我们旨在确定在无 NMBA 情况下使用 1 或 2 mg/kg 氯胺酮诱导麻醉时，达到可接受插管条件所需的瑞芬太尼有效推注剂量。
在这项前瞻性、双盲、随机、上下序贯分配研究中，我们纳入了接受全身麻醉行腹股沟疝手术的 3-12 岁小儿患者。患者被随机分配至两组中的一组，分别接受静脉注射 1.0 mg/kg（K1 组）或 2.0 mg/kg（K2 组）氯胺酮，直至达到 7 个成功-失败配对。每位患者的瑞芬太尼剂量使用改良 Dixon 上下法确定，初始剂量为 2.5 μg/kg，步长为 0.5 μg/kg。
共纳入 51 例患者（K1 组 22 例，K2 组 29 例）。在无 NMBA 情况下使用氯胺酮诱导麻醉时，获得可接受插管条件的瑞芬太尼有效剂量（ED）50 在 K1 组为 3.2 μg/kg，在 K2 组为 1.6 μg/kg。与低剂量瑞芬太尼（2 mg/kg 氯胺酮）相比，高剂量瑞芬太尼（1 mg/kg 氯胺酮）与更严重的胸壁僵硬以及更低的平均血压和心率相关。
在无 NMBA 情况下使用 1 mg/kg 氯胺酮诱导麻醉时，儿童患者获得可接受插管条件所需的瑞芬太尼 ED50 是使用 2 mg/kg 氯胺酮时的两倍。2 mg/kg 氯胺酮与瑞芬太尼联合使用可更好地预防胸壁僵硬。
