the effect of patients’ position on arterial oxygenation during one-lung and two-lung ventilation in thoracic surgery: smoker vs. nonsmoker patients (a pilot study)

Background: one-lung ventilation (olv) is often required to facilitate surgical exposure. hypoxemia is a common disorder during thoracic surgery. objectives: we studied whether changing from the supine to the lateral position during olv and two-lung ventilation (tlv) in thoracic surgery would affect positions on arterial oxygen pressure (pao 2) in two groups of smokers and nonsmokers. methods: this single-blinded prospective observational pilot study was conducted on patients who underwent thoracotomy under general anesthesia. the effect of lateral and supine pao was investigated in 15 patients with a history of smoking (≥ 40 packs/year) and 15 patients without. the data were analyzed via descriptive and inferential statistics in spss v. 19. results: arterial oxygen pressure did not significantly differ between the two groups in the supine tlv (p = 0.98), supine olv (p = 0.16), lateral tlv (p = 0.06), and lateral olv (p = 0.31). however, the pao 2level was higher in smokers than in nonsmokers (except during supine tlv). changing the position from supine to lateral caused a relative decrease in pao2(except during tlv in smokers) during tlv and olv. this reduction in pao 2levels was less in smokers (72.12) than in nonsmokers (95.28). oxygen saturation (spo 2) levels were the same in all positions regardless of whether they were a smoker or nonsmoker. conclusions: changing the position from supine to lateral had no significant effects on pao 2and spo 2levels in smoker and nonsmoker patients during olv and tlv in thoracic surgery.