JAMA Surg：当前吸烟者术后风险增加

　　根据6月19日在线发表于《美国医学会杂志·外科学》的一篇报道，当前吸烟与大手术后死亡及其他不良结局风险增加有关，而既往吸烟无此关联，即便在未患吸烟相关疾病(如心血管疾病、慢性肺病或癌症)的患者中亦如此，提示吸烟或可通过急性或亚临床慢性心血管及呼吸系统发病机制产生不良影响。

　　贝鲁特美国大学(黎巴嫩)医学中心的Khaled M. Musallam医生及其合作者指出，由于停止吸烟在降低手术合并症发生率和死亡率方面有明显益处，因此外科手术小组应该更加积极地参与对控制吸烟措施的优化。

　　在该研究中，Musallam医生及其同事利用美国外科医师协会全国外科手术质量改进计划(MSQIP)的数据，探讨了吸烟对手术结局的影响。他们分析了607,558例在2年期间接受大手术的患者，涉及200家医院，这些医院分别分布于美国、加拿大、黎巴嫩及阿联酋。患者的平均年龄为56岁(范围：16~90岁)；男性占43%，女性占57%。共有125,192例患者(21%)为当前吸烟者，78,763例(13%)在手术前至少1年戒烟，其余为从不吸烟者。

　　研究结果显示，只有当前吸烟者的30天死亡率升高几率增加，同时，他们在术后30天内发生心肌梗死(MI)或卒中等不良动脉事件的风险以及肺炎、需要插管及需要呼吸机支持等不良呼吸系统事件的风险增加。无论当前吸烟者处于哪个年龄段，其发生这些不良结局的风险均较高，但在40岁以上的吸烟群体中风险尤高。不论患者是男性还是女性，进行的是门诊手术还是住院手术，全麻还是其他类型的麻醉，也不论具体进行的是哪个领域的手术，是择期还是急诊手术，观察结果均如此。当前吸烟与不良结局之间的相关性在一项敏感性分析中仍具有鲁棒性。

　　另外，对患者的吸烟史进行分析发现，这种相关性呈剂量依赖性，即随着吸烟的包-年数增加，发生不良动脉及呼吸系统事件的概率也增加。即使是吸烟史＜10包-年的当前“轻度”吸烟者，术后死亡和并发症风险也增加。

　　上述研究结果提示，应该对重度吸烟者及早采取干预措施，并且应该将近期及轻度吸烟者列入目标人群范围。

Smoking and the Risk of Mortality and Vascular and Respiratory Events in Patients Undergoing Major Surgery
Importance
The effects of smoking on postoperative outcomes in patients undergoing major surgery are not fully established. The association between smoking and adverse postoperative outcomes has been confirmed. Whether the associations are dose dependent or restricted to patients with smoking-related disease remains to be determined.
Objective
To evaluate the association between current and past smoking on the risk of postoperative mortality and vascular and respiratory events in patients undergoing major surgery.
Design
Cohort study using the American College of Surgeons National Surgical Quality Improvement Program database. We obtained data on smoking history, perioperative risk factors, and 30-day postoperative outcomes. We assessed the effects of current and past smoking (>1 year prior) on postoperative outcomes after adjustment for potential confounders and effect mediators (eg, cardiovascular disease, chronic obstructive pulmonary disease, and cancer). We also determined whether the effects are dose dependent through analysis of pack-year quintiles.
Setting and Participants
A total of 607 558 adult patients undergoing major surgery in non–Veterans Affairs hospitals across the United States, Canada, Lebanon, and the United Arab Emirates during 2008 and 2009.
Main Outcomes and Measures
The primary outcome measure was 30-day postoperative mortality; secondary outcome measures included arterial events (myocardial infarction or cerebrovascular accident), venous events (deep vein thrombosis or pulmonary embolism), and respiratory events (pneumonia, unplanned intubation, or ventilator requirement >48 hours).
Results
The sample included 125 192 current (20.6%) and 78 763 past (13.0%) smokers. Increased odds of postoperative mortality were noted in current smokers only (odds ratio, 1.17 [95% CI, 1.10-1.24]). When we compared current and past smokers, the adjusted odds ratios were higher in the former for arterial events (1.65 [95% CI, 1.51-1.81] vs 1.20 [1.09-1.31], respectively) and respiratory events (1.45 [1.40-1.51] vs 1.13 [1.08-1.18], respectively). No effects on venous events were observed. The effects of smoking mediated through smoking-related disease were minimal. The increased adjusted odds of mortality in current smokers were evident from a smoking history of less than 10 pack-years, whereas the effects of smoking on arterial and respiratory events were incremental with increased pack-years.
Conclusions and Relevance
Smoking cessation at least 1 year before major surgery abolishes the increased risk of postoperative mortality and decreases the risk of arterial and respiratory events evident in current smokers. These findings should be carried forward to evaluate the value and cost-effectiveness of intervention in this setting. Our study should increase awareness of the detrimental effects of smoking—and the benefits of its cessation—on morbidity and mortality in the surgical setting.