Smoking as a risk factor for intraoperative hypoxemia during one lung ventilation

Background: Smoking is associated with many intra and postoperative events, especially respiratory complications. Hypoxemia and airway damage are found to aggravate any pre-existing respiratory pathology among smokers. One lung ventilation (OLV) carries a 4-10 % risk of development of hypoxia. Aim: The purpose of this study was to predict the incidence of hypoxemia for smokers during OLV for patients undergoing video-assisted thoracoscopic surgery (VATS). Patients and methods: Sixty patients undergoing VATS using OLV by double lumen tube were included in this pilot cross-sectional study. These patients were divided into 2 groups, group S which included 30 heavy smoker patients (smoking more than 20 cigarettes per day for more than 20 years) and group NS which included 30 non-smoker patients. Intra and postoperative arterial oxygen tension (PaO₂), arterial carbon dioxide tension (PaCO₂), and intraoperative peak airway pressure were compared between the 2 groups. Results: PaO₂ was significantly higher in the non-smoker group than in the smoker group, both at the start and end of OLV. It was 173 ± 68 mmHg for NS compared with 74 ± 10.8 mmHg for S at the start of OLV; at the end of OLV it was 410 ± 78 mmHg for the former and 360 ± 72 mmHg for the latter (P < 0.05). Conclusion: From this study it can be concluded that for heavy smoker patients there was a significant reduction in arterial oxygen tension (PaO₂) in comparison with non-smokers. However, hypoxemia reported for both groups was comparable.