Monitoring of Exhaled Carbon Monoxide to Promote Preoperative Smoking Abstinence

Objective: Brief preoperative abstinence from cigarette smoking reduces risk for perioperative complications in surgical patients. This study tested the hypothesis that the efficacy of brief advice recommending abstinence the morning of surgery would be increased if patients were informed that exhaled carbon monoxide (CO) levels would be monitored to assess compliance. Method: Cigarette smokers scheduled for elective surgery were randomized to 2 groups. Subjects in both groups received brief advice (BA) recommending smoking abstinence on the morning of surgery. The CO-informed + BA group was also told that their smoking status would be checked before surgery using exhaled CO monitoring; the other group (BA only) was not. Results: CO levels on the morning of surgery were not significantly different in the CO-informed + BA (n = 80) and BA-only groups (n = 84; M = 9.7, SD = 8.0, and M = 9.3, SD = 6.6 parts per million (ppm), respectively, p = .67). When the data from both groups were combined and compared with data from 506 additional surgical patients receiving only usual care, CO levels were significantly higher in those patients receiving usual care. Conclusions: Informing patients that their smoking status would be checked the morning of surgery by CO monitoring does not further increase the efficacy of BA to abstain the morning of surgery.