Clinical question: Is there an association between current and past smoking on outcomes among patients having major surgery?
Background: Smoking is associated with adverse postoperative outcomes, but it is not known whether the associations are dose-dependent or limited to patients with smoking-related diseases. Smoking-related effects on postoperative events among patients having major surgery are also not well established.
Study design: Retrospective cohort study.
Setting: Four hundred forty-eight non-VA hospitals across the U.S., Canada, Lebanon, and the United Arab Emirates.
Synopsis: Data from 607,558 adult patients undergoing major surgery were obtained from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. After adjusting for confounders (cardiopulmonary diseases and cancer), the effects of current and past smoking (quit >1 year prior) on 30-day postoperative outcomes were measured.
There were 125,192 (21%) current smokers and 78,763 (13%) past smokers. Increased odds of post-op mortality were noted in current smokers only (odds ratio [OR] 1.17; 95% CI, 1.10–1.24). The adjusted odds ratios were higher for arterial and respiratory events among current smokers compared with past smokers (OR 1.65; 95% CI, 1.51–1.81 vs. OR 1.20; CI, 1.09–1.31 for arterial events, respectively) and (OR, 1.45; CI, 1.40–1.51 vs. OR, 1.13; CI, 1.08–1.18, for respiratory events, respectively). No significant effects on venous events were observed.
There was an increased adjusted odds of mortality for current smokers with <10 pack-years, while the effects on arterial and respiratory events increased incrementally with increased pack-years. Smoking was associated with adverse post-op outcomes regardless of smoking-related diseases. Variability in hospital quality or surgical strategies may have confounded the results.
Bottom line: Among patients undergoing major surgery, current but not past smoking was associated with higher mortality; smoking cessation for at least a year prior to surgery may decrease postoperative adverse events.
Citation: Musallam KM, Rosendaal FR, Zaatari G, et al. Smoking and the risk of mortality and vascular and respiratory events in patients undergoing major surgery. JAMA Surg. 2013;148:755-762.