From the Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, and Anaesthesia, Perioperative and Pain Medicine Unit, and Department of Pharmacology and Therapeutics, University of Melbourne, and Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia (K.L.); Department of Anaesthesia and Perioperative Medicine, The Alfred Hospital, and Academic Board of Anaesthesia and Perioperative Medicine, and Department of Epidemiology and Preventive Medicine, Monash University, and National Health and Medical Research Council Practitioner Fellow, Melbourne, Australia (P.S.M.); Department of Epidemiology and Preventive Medicine (J.K., A.F.), Monash University, Melbourne, Australia; Department of Anaesthesia, Austin Hospital, and Department of Surgery, University of Melbourne, Melbourne, Australia (P.J.P.); Department of Anaesthesia, Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China (M.T.V.C.); Department of Anaesthesia and Pain Medicine, Royal Perth Hospital, Perth, Australia, and School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia (M.J.P.); Department of Outcomes Research, Cleveland Clinic, Cleveland, Ohio (D.I.S.); Department of Anesthesia, University of Toronto, and Department of Anaesthesia, Toronto General Hospital, Toronto, Ontario, Canada (W.S.B.); Population Health Research Institute, Hamilton Health Sciences and McMaster University, and Departments of Medicine, Clinical Epidemiology, and Biostatistics, McMaster University, Hamilton, Ontario, Canada (P.J.D.); and Department of Anaesthesia and Perioperative Medicine, Alfred Hospital, and Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia (S.W.).
Anesthesiology. 2015 Dec;123(6):1267-80. doi: 10.1097/ALN.0000000000000908.
The Evaluation of Nitrous Oxide in the Gas Mixture for Anaesthesia (ENIGMA)-II trial randomly assigned 7,112 noncardiac surgery patients at risk of perioperative cardiovascular events to 70% N2O or 70% N2 groups. The aim of this follow-up study was to determine the effect of nitrous oxide on a composite primary outcome of death and major cardiovascular events at 1 yr after surgery.
One-year follow-up was conducted via a medical record review and telephone interview. Disability was defined as a Katz index of independence in activities of daily living score less than 8. Adjusted odds ratios and hazard ratios were calculated as appropriate for primary and secondary outcomes.
Among 5,844 patients evaluated at 1 yr, 435 (7.4%) had died, 206 (3.5%) had disability, 514 (8.8%) had a fatal or nonfatal myocardial infarction, and 111 (1.9%) had a fatal or nonfatal stroke during the 1-yr follow-up period. Exposure to nitrous oxide did not increase the risk of the primary outcome (odds ratio, 1.08; 95% CI, 0.94 to 1.25; P = 0.27), disability or death (odds ratio, 1.07; 95% CI, 0.90 to 1.27; P = 0.44), death (hazard ratio, 1.17; 95% CI, 0.97 to 1.43; P = 0.10), myocardial infarction (odds ratio, 0.97; 95% CI, 0.81 to 1.17; P = 0.78), or stroke (odds ratio, 1.08; 95% CI, 0.74 to 1.58; P = 0.70).
These results support the long-term safety of nitrous oxide administration in noncardiac surgical patients with known or suspected cardiovascular disease.
在一项评估麻醉混合气中氧化亚氮（ENIGMA-II）的试验中，7112 名有围手术期心血管事件风险的非心脏手术患者被随机分配到 70%氧化亚氮或 70%氮气组。本随访研究的目的是确定氧化亚氮对手术后 1 年死亡和主要心血管事件复合主要结局的影响。
通过病历回顾和电话访谈进行 1 年随访。残疾定义为日常生活活动的 Katz 独立性指数评分<8。适当计算了主要和次要结局的调整比值比和风险比。
在 1 年评估的 5844 名患者中，435 名（7.4%）死亡，206 名（3.5%）残疾，514 名（8.8%）发生致死性或非致死性心肌梗死，111 名（1.9%）发生致死性或非致死性卒中。在 1 年随访期间，接触氧化亚氮并未增加主要结局的风险（比值比，1.08；95%置信区间，0.94 至 1.25；P=0.27）、残疾或死亡（比值比，1.07；95%置信区间，0.90 至 1.27；P=0.44）、死亡（风险比，1.17；95%置信区间，0.97 至 1.43；P=0.10）、心肌梗死（比值比，0.97；95%置信区间，0.81 至 1.17；P=0.78）或卒中（比值比，1.08；95%置信区间，0.74 至 1.58；P=0.70）。
这些结果支持在有已知或疑似心血管疾病的非心脏手术患者中使用氧化亚氮的长期安全性。
