A prospective study of tobacco smoking as a predictor of complications in general surgery

OBJECTIVE: To analyze whether tobacco smoking is related to nosocomial infection, admission to the intensive care unit, in-hospital death, and length of stay. DESIGN: A prospective cohort study. SETTING: The Service of General Surgery of a tertiary-care hospital. PATIENTS: A consecutive series of patients admitted for more than 1 day (N = 2,989). RESULTS: Sixty-two (2.1%) patients died and 503 (16.8%) acquired a nosocomial infection, of which 378 (12.6%) were surgical site and 44 (1.5%) were lower respiratory tract. Smoking (mainly past smoking) was associated with a worse health status (eg, longer preoperative stay and higher American Society of Anesthesiologists score). A long history of smoking (greater than or equal to 51 pack-years) increased postoperative admission to the intensive care unit (adjusted odds ratio [OR] = 2.86; 95% confidence interval [CI95] 1.21 to 6.77) and in-hospital mortality (adjusted OR = 2.56; CI 95, 1.10 to 5.97). There was no relationship between current smoking and surgical-site infection (adjusted OR = 0.99; CI95, 0.72 to 1.35), whereas a relationship was observed between past smoking and surgical-site infection (adjusted OR = 1.46; CI95, 1.02 to 2.09). Current smoking and, to a lesser degree, past smoking augmented the risk of lower respiratory tract infection (adjusted OR = 3.21; CI95, 1.21 to 8.51). Smokers did not undergo additional surgical procedures more frequently during hospitalization. In the multivariate analysis, length of stay was similar for smokers and nonsmokers. CONCLUSION: Smoking increases in-hospital mortality, admission to the intensive care unit, and lower respiratory tract infection, but not surgical-site infection. Deleterious effects of smoking are also observed in past smokers and they cannot be counteracted by hospital cessation programs.