One-lung ventilation (OLV) is essential part of anesthesia during thoracic procedures. However, OLV induces a drastic increase of intrapulmonary shunt due to maintained pulmonary perfusion through the nonventilated lung, which may result in severe hypoxemia. Although the protective mechanisms of hypoxic pulmonary vasoconstriction favorably modulate pulmonary perfusion to the ventilated lung, the effect is attenuated in patients with history of chronic obstructive pulmonary disease (COPD), which alters compliance of the pulmonary artery.

Salbutamol is a selective short-acting beta2-agonist and when inhaled during OLV, it acts selectively on the pulmonary vasculature reducing pulmonary vascular resistance of well-ventilated lung. We hypothesized that inhaled salbutamol would alleviate ventilation-perfusion mismatch during OLV of COPD patients, and aimed to assess the effects of salbutamol on oxygenation in these patients.

Inclusion Criteria:

• Patient age 40~80yrs, scheduled for videoscope-assisted pulmonary lobectomy
• American Society of Anesthesiologists Class III 또는 IV
• Moderate or more severe COPD according to GOLD criteria (FEV1/FVC<70%, FEV1<80%)

Exclusion Criteria:

• New York Heart Association class >II
• AST level ≥100 IU/mL or ALT ≥ level 50 IU/L
• Creatinine clearance < 30mL/min
• History of severe coronary artery occlusive disease, unstable angina, or recent myocardial infarction within 6 months
• History of pulmonary hypertension or pulmonary edema
• History of cerebrovascular accident within 3 months