64 year old patient with severe RUQ pain and obstructive jaundice. Invesigations proved that he has Gall stones and common duct stone. He is a 60 pack year smoker and carries a diagnosis of COPD for the past 5 years. Hes is short of breath at rest and is using accessory mucles of respiration. He has early morning cough with slight yellow tinged sputum. You are being asked to provide a pulmonary clearance for Cholecystectomy and common duct exploration.