Preoperative Smoking Cessation: Importance and Consequences

By February 9, 2018Uncategorized

Millions of cigarette smokers undergo surgical procedures in the United States every day. The effects of smoking on the surgical patient have been well-studied, and those of tobacco abstinence equally so. Even after accounting for smoking related diseases such as COPD and heart disease, smoking itself is an independent risk factor for surgical complications. One meta-analysis found relative risks of 2.15 for wound-related complications in smokers compared to non-smokers, 1.73 for pulmonary complications, and 1.60 for admission to the ICU. It is estimated that smoking results in roughly $10 billion in annual postoperative costs in the United States.

Smoking is known to accelerate atherosclerosis by way of endothelial damage, oxidative injury, pro-thrombosis, and promoting an unfavorable lipid profile. In addition to increasing the risk of coronary and peripheral vascular disease, smoking also elevates heart rate, blood pressure, and myocardial contractility due to increased sympathetic tone. In those with preexisting CAD, nicotine can cause coronary vasoconstriction. Carboxyhemoglobin levels can exceed 10% in smokers, compromising oxygen delivery.  The cardiovascular benefits of smoking cessation include decreasing the risk of all-cause mortality in smokers with coronary disease by 1/3 after at least several months of abstinence. More immediate benefits include decreased carbon monoxide levels and a decreased sympathetic tone.

Smoking cessation benefits

While some pulmonary manifestations of smoking are irreversible (COPD, malignancies), abstinence can improve cough and wheezing after several weeks. Mucus production may increase over the initial weeks of cessation, however mucociliary clearance seem to partially improve after one week. Smokers are at higher risk for perioperative respiratory failure, laryngospasm and other induction-related airway events, pneumonia, bronchospasm, and unanticipated ICU admission. These complications were significantly decreased after 8 weeks of abstinence in several observational studies, with full benefit after 12 weeks. However some complications such as laryngospasm may be decreased after only a few days, due to decreased sensitivity to upper airway stimulation by chemical irritants.

Wound infections and dehiscence have long been associated with smoking, as well as bone nonunion. The duration of abstinence necessary to reverse this is on the order of weeks, however more studies need to be conducted to better define this period.

Smoking cessation is overwhelmingly beneficial in terms of perioperative morbidity and mortality. The longer the abstinence, the more profound the effects, but even brief periods of cessation may decrease intra- and post-operative complications. Anesthesia providers are in a unique position to influence patients to stop smoking prior to their surgical procedures, and can be an important step in achieving long-term abstinence.

 

References

Nolan MBWarner DO. Perioperative tobacco use treatments: putting them into practice. BMJ 2017;358:j3340

Warner DO. Perioperative abstinence from cigarettes: physiologic and clinical consequences. Anesthesiology 2006;358:356-67.

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