Uppal Vishal, Retter Susanne, Shanthanna Harsha, Prabhakar Christopher, McKeen Dolores M
From the *Department of Anesthesia, Perioperative Medicine and Pain Management, Dalhousie University, Nova Scotia Health Authority and IWK (Izaak Walton Killam) Health Centre, Halifax, Nova Scotia, Canada; †Department of Anesthesia, McMaster University, St Joseph's Health Care, Hamilton, Ontario, Canada; and ‡Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, St Paul's Hospital, Vancouver, British Columbia, Canada.
Anesth Analg. 2017 Nov;125(5):1627-1637. doi: 10.1213/ANE.0000000000002254.
It is widely believed that the choice between isobaric bupivacaine and hyperbaric bupivacaine formulations alters the block characteristics for the conduct of surgery under spinal anesthesia. The aim of this study was to systematically review the comparative evidence regarding the effectiveness and safety of the 2 formulations when used for spinal anesthesia for adult noncesarean delivery surgery.
Key electronic databases were searched for randomized controlled trials, excluding cesarean delivery surgeries under spinal anesthesia, without any language or date restrictions. The primary outcome measure for this review was the failure of spinal anesthesia. Two independent reviewers selected the studies and extracted the data. Results were expressed as relative risk (RR) or mean differences (MDs) with 95% confidence intervals (CIs).
Seven hundred fifty-one studies were identified between 1946 and 2016. After screening, there were 16 randomized controlled clinical trials, including 724 participants, that provided data for the meta-analysis. The methodological reporting of most studies was poor, and appropriate judgment of their individual risk of bias elements was not possible. There was no difference between the 2 drugs regarding the need for conversion to general anesthesia (RR, 0.60; 95% CI, 0.08-4.41; P = .62; I = 0%), incidence of hypotension (RR, 1.15; 95% CI, 0.69-1.92; P = .58; I = 0%), nausea/vomiting (RR, 0.29; 95% CI, 0.06-1.32; P = .11; I = 7%), or onset of sensory block (MD = 1.7 minutes; 95% CI, -3.5 to 0.1; P = .07; I = 0%). The onset of motor block (MD = 4.6 minutes; 95% CI, 7.5-1.7; P = .002; I = 78%) was significantly faster with hyperbaric bupivacaine. Conversely, the duration of motor (MD = 45.2 minutes; 95% CI, 66.3-24.2; P < .001; I = 87%) and sensory (MD = 29.4 minutes; 95% CI, 15.5-43.3; P < .001; I = 73%) block was longer with isobaric bupivacaine.
Both hyperbaric bupivacaine and isobaric bupivacaine provided effective anesthesia with no difference in the failure rate or adverse effects. The hyperbaric formulation allows for a relatively rapid motor block onset, with shorter duration of motor and sensory block. The isobaric formulation has a slower onset and provides a longer duration of both sensory and motor block. Nevertheless, the small sample size and high heterogeneity involving these outcomes suggest that all the results should be treated with caution.
人们普遍认为，等比重布比卡因和重比重布比卡因制剂的选择会改变脊髓麻醉下手术的阻滞特征。本研究的目的是系统评价这两种制剂用于成人非剖宫产手术脊髓麻醉时有效性和安全性的比较证据。
检索主要电子数据库以查找随机对照试验，排除脊髓麻醉下的剖宫产手术，无任何语言或日期限制。本综述的主要结局指标是脊髓麻醉失败。两名独立的评价者选择研究并提取数据。结果以相对风险（RR）或平均差（MDs）及95%置信区间（CIs）表示。
1946年至2016年间共识别出751项研究。筛选后，有16项随机对照临床试验，包括724名参与者，为荟萃分析提供了数据。大多数研究的方法学报告质量较差，无法对其个体偏倚风险因素进行恰当判断。两种药物在转为全身麻醉的必要性（RR，0.60；95%CI，0.08 - 4.41；P = 0.62；I² = 0%）、低血压发生率（RR，1.15；95%CI，0.69 - 1.92；P = 0.58；I² = 0%）、恶心/呕吐（RR，0.29；95%CI，0.06 - 1.32；P = 0.11；I² = 7%）或感觉阻滞起效时间（MD = 1.7分钟；95%CI， - 3.5至0.1；P = 0.07；I² = 0%）方面无差异。重比重布比卡因的运动阻滞起效时间（MD = 4.6分钟；95%CI，7.5 - 1.7；P = 0.002；I² = 78%）明显更快。相反，等比重布比卡因的运动（MD = 45.2分钟；95%CI，66.3 - 24.2；P < 0.001；I² = 87%）和感觉（MD = 29.4分钟；95%CI，15.5 - 43.3；P < 0.001；I² = 73%）阻滞持续时间更长。
重比重布比卡因和等比重布比卡因均提供有效的麻醉，失败率或不良反应无差异。重比重制剂可使运动阻滞起效相对较快，运动和感觉阻滞持续时间较短。等比重制剂起效较慢，感觉和运动阻滞持续时间较长。然而，涉及这些结局的样本量小且异质性高，提示所有结果均应谨慎对待。
