Patients who quit smoking shortly before undergoing surgery are not at increased risk of postoperative complications, compared with those who continue to smoke, according to a report published online March 14 in the Archives of Internal Medicine.
"Until some new evidence of harm emerges, firm advice to stop smoking and an offer of smoking cessation treatment to those who need it can be provided to presurgical patients at any time," said Katie Myers of Queen Mary, University of London, and her associates.
Publication of a study in 1989 with 39 subjects suggested that "stopping smoking leads to a decrease in coughing and an increase in sputum production." Although that article did not actually show a significant effect of smoking cessation on postoperative complications, it has continued to influence routine practice; in fact, some treatment guidelines recommend against smoking cessation in the 2 months prior to surgery "to minimize the increase in pulmonary complications in recent quitters."
Ms. Myers and her colleagues reviewed the literature for all studies that allowed comparisons of postoperative complications in patients who stopped smoking 8 weeks or less before undergoing surgery (recent quitters) and patients who continued to smoke. They then performed a meta-analysis of the nine studies that did so, rating as "high quality" the three studies that also used biochemical testing to validate subjects’ self-report of their smoking status.
These studies involved 889 subjects, including 448 recent quitters and 441 continuing smokers.
Only one of the nine studies showed a significant effect of smoking cessation, and that was in favor of recent quitting. When the results were pooled, there was "no beneficial or detrimental effect of quitting within 8 weeks before surgery, compared with continued smoking," the researchers said.
The results were the same in an analysis of the three high-quality studies, and likewise when the analysis was restricted to only pulmonary postoperative complications.
"In conclusion, there is currently no suggestion, either from any single study or from combinations of studies, that quitting smoking shortly before surgery increases postoperative complications," the investigators said (Arch. Intern. Med. 2011 [doi:10.1001/archinternmed.2011.97]).
The reluctance to allow or encourage smoking cessation shortly before surgery is based on unconfirmed assumptions. Only one study in the literature has directly examined mucociliary clearance in surgical patients shortly after smoking cessation, and that study found no significant difference between surgical patients who had recently quit and those who continued to smoke, Ms. Myers and her associates noted.
"No data are available on the effects of only a few days’ abstinence from smoking. Early abstinence generates more intense withdrawal discomfort, but there is no clear rationale to expect this to translate into postoperative complications," they added.
However, they acknowledged that their study is limited by its observational nature and by the small number of studies available for review that have evaluated this issue. "Our findings are necessarily tentative and may be modified when more data become available," the researchers said.
One of Ms. Myers’ associates is supported by the U.K. Center for Tobacco Control Studies. Two associates reported ties to GlaxoSmithKline, Novartis, Pfizer Global, and Johnson & Johnson, which manufacture smoking cessation products.