Is there benefit in smoking cessation prior to cardiac surgery?

Abstract

A best evidence topic was written according to a structured protocol. The question addressed was whether smoking cessation prior to cardiac surgery would result in a greater freedom from postoperative complications. A total of 564 papers were found using the reported searches, of which five represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. Reported measures were operative mortality, pulmonary complications, infective complications, neurological complications, transfusion requirements, duration of ventilation, intensive care unit and hospital stay, intensive care unit re-admission, postoperative gas exchange parameters and postoperative pulmonary function. The largest of the best evidence studies demonstrated a significant reduction in pulmonary complications in non-smokers (P < 0.001); however, there was an increased requirement for transfusion in this cohort (P = 0.002). There were non-significant reductions in neurological complications, infective complications and re-admissions to intensive care. Another large cohort study demonstrated significant reductions in non-smokers in mortality (P < 0.0001), pulmonary complications (P = 0.0002), infection (P < 0.0007), intensive care unit re-admission (P = 0.0002), duration of mechanical ventilation (P = 0.026) and intensive care unit stay (P = 0.002). A larger cohort study again demonstrated significant reductions in non-smokers in pulmonary complications (P < 0.002), duration of mechanical ventilation (P < 0.012) and intensive care unit stay (P < 0.005). A smaller prospective cohort study reported significantly raised PaO(2) (P = 0.0091) and reduced PaCO(2) (P < 0.0001) levels in the non-smokers as well as improved FVC and FEV(1) (P < 0.0001). There were also reductions in duration of intubation (P < 0.0001), intensive care unit stay (P < 0.0001) and hospital stay (P < 0.0013). Another small cohort study reporting outcomes of heart transplantation demonstrated significant improvement in non-smokers in terms of survival (P = 0.031), duration of intubation (P = 0.05) and intensive care unit stay (P = 0.021). We conclude that there is strong evidence demonstrating superior outcomes in non-smokers following cardiac surgery and advocate the necessity of smoking cessation as soon as possible prior to cardiac surgery.