Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Department of Anesthesiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Medicina (Kaunas). 2023 Mar 1;59(3):484. doi: 10.3390/medicina59030484.
The dose selection for isobaric bupivacaine determines the success of spinal anesthesia (SA). A dose higher than the optimal dose causes high SA, whereas an underdose leads to inadequate spread of cephalad. As it involves anatomical and physiological alterations, the dosing should be reduced with advancing age and body mass index values. Therefore, this study aimed to demonstrate the association between the isobaric bupivacaine dose and block height, and to determine the dose intervals of bupivacaine to achieve the T5-T10 sensory block with a low probability of high SA in elderly and overweight patients. This retrospective observational study recruited 1079 adult patients who underwent SA with 0.5% isobaric bupivacaine from 2018 to 2021. The patients were divided into four categories: category 1 (age < 60, BMI < 25), category 2 (age < 60, BMI ≥ 25), category 3 (age ≥ 60, BMI < 25), and category 4 (age ≥ 60, BMI ≥ 25). The bupivacaine dose and sensory block height (classified into three levels: high (T1-T4), favorable (T5-T10), and low (T11-L2)) were recorded. The sensory block level increased significantly with increasing doses of bupivacaine for patients in categories 1 and 2. The suggested dose ranges for the favorable block heights were 15-17 and 10.5-16 mg in patient categories 1-2 and 3-4, respectively. In these dose ranges, the probability range of high SA was 10-15%. The sensory block height following SA was associated with the bupivacaine dose in patients aged <60 years. Regardless of the BMI, the suggested dose ranges of 0.5% isobaric bupivacaine are 15-17 mg (3.0-3.4 mL) and 10.5-16 mg (2.1-3.2 mL) for patients aged <60 and ≥60 years, respectively.
等比重布比卡因的剂量选择决定了脊麻（SA）的成败。剂量高于最佳剂量会导致高 SA，而剂量不足则会导致头向扩散不足。由于涉及解剖和生理变化，剂量应随年龄和体重指数的增加而减少。因此，本研究旨在证明等比重布比卡因剂量与阻滞平面高度之间的关系，并确定布比卡因的剂量间隔，以在老年和超重患者中实现 T5-T10 感觉阻滞，同时降低高 SA 的可能性。 本回顾性观察性研究纳入了 2018 年至 2021 年间接受 0.5%等比重布比卡因脊麻的 1079 例成年患者。患者分为四组：第 1 组（年龄<60 岁，BMI<25）、第 2 组（年龄<60 岁，BMI≥25）、第 3 组（年龄≥60 岁，BMI<25）和第 4 组（年龄≥60 岁，BMI≥25）。记录了布比卡因剂量和感觉阻滞平面高度（分为三个水平：高（T1-T4）、有利（T5-T10）和低（T11-L2））。 对于第 1 组和第 2 组患者，随着布比卡因剂量的增加，感觉阻滞平面显著升高。对于第 1-2 组和第 3-4 组患者，有利阻滞高度的建议剂量范围分别为 15-17mg 和 10.5-16mg。在这些剂量范围内，高 SA 的概率范围为 10-15%。 在年龄<60 岁的患者中，SA 后感觉阻滞高度与布比卡因剂量相关。无论 BMI 如何，0.5%等比重布比卡因的建议剂量范围分别为 15-17mg（3.0-3.4mL）和 10.5-16mg（2.1-3.2mL），适用于年龄<60 岁和≥60 岁的患者。
