Department of Neurosurgery, Yale University School of Medicine, New Haven, CT.
Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH.
J Neurosurg Anesthesiol. 2022 Jul 1;34(3):306-312. doi: 10.1097/ANA.0000000000000771. Epub 2021 Apr 23.
The Evaluation of Nitrous Oxide in the Gas Mixture for Anesthesia (ENIGMA)-I and ENIGMA-II were randomized clinical trials that assessed the safety of nitrous oxide anesthesia in patients undergoing noncardiac surgery. In this study, we performed an exploratory pooled analysis of both ENIGMA trials to assess the safety of nitrous oxide in a selected group of patients undergoing neurosurgery.
Data from each ENIGMA trial were collated into a single database. Information regarding patient demographics, comorbidities, medication use, anesthesia, surgical procedure, and postoperative complications was extracted. Multivariate logistic regression was conducted for postoperative complications to assess the risk associated with nitrous oxide.
A total of 830 patients were included in our analysis: 417 received nitrous oxide anesthesia, and 413 received nitrous oxide-free anesthesia. Baseline patient and perioperative characteristics were comparable. Procedural data were available for 535 patients (64%); of these, 507 (95%) underwent spinal neurosurgery and 28 (5%) underwent cranial neurosurgery. Patients in the nitrous oxide group had lower inspired oxygen concentration (30% vs. 38%; P<0.001) and end-tidal volatile agent concentration (0.56 vs. 0.89 minimal alveolar concentration equivalents; P<0.001) compared with the nitrous oxide-free group. Use of nitrous oxide was not associated with increased risk of postoperative complications (myocardial infarction, cardiac arrest, stroke, infection, severe vomiting, fever, pneumonia, pneumothorax, blood transfusion, venous thromboembolism, or death) (odds ratio: 1.22; 95% confidence interval: 0.89-1.65; P=0.22) or prolonged length of hospital stay (median 5.0 vs. 4.2 d for nitrous oxide and nitrous oxide-free groups; P=0.28).
Nitrous oxide did not increase the risk of postoperative complications or prolonged length of hospital stay in the neurosurgical cohort enrolled in the ENIGMA-I and ENIGMA-II trials.
《氧化亚氮在麻醉混合气体中的评估（ENIGMA）-I 和 ENIGMA-II》是两项随机临床试验，评估了非心脏手术患者使用氧化亚氮麻醉的安全性。在这项研究中，我们对两项 ENIGMA 试验进行了探索性汇总分析，以评估氧化亚氮在接受神经外科手术的特定患者群体中的安全性。
将每项 ENIGMA 试验的数据汇总到一个单一的数据库中。提取患者人口统计学、合并症、用药、麻醉、手术程序和术后并发症的信息。使用多变量逻辑回归评估术后并发症，以评估与氧化亚氮相关的风险。
共有 830 名患者纳入我们的分析：417 名患者接受氧化亚氮麻醉，413 名患者接受无氧化亚氮麻醉。基线患者和围手术期特征具有可比性。535 名患者（64%）的手术数据可用；其中 507 名（95%）患者接受脊柱神经外科手术，28 名（5%）患者接受颅神经外科手术。与无氧化亚氮组相比，氧化亚氮组的吸入氧气浓度（30%对 38%；P<0.001）和呼气末挥发性麻醉剂浓度（0.56 对 0.89 最小肺泡浓度当量；P<0.001）较低。使用氧化亚氮与术后并发症（心肌梗死、心脏骤停、中风、感染、严重呕吐、发热、肺炎、气胸、输血、静脉血栓栓塞或死亡）风险增加无关（比值比：1.22；95%置信区间：0.89-1.65；P=0.22）或住院时间延长（中位数 5.0 对 4.2 d 用于氧化亚氮和无氧化亚氮组；P=0.28）无关。
在 ENIGMA-I 和 ENIGMA-II 试验中纳入的神经外科队列中，氧化亚氮并未增加术后并发症或住院时间延长的风险。
