Prior to occlusion of any major pulmonary blood vessels during a thoracotomy, applying positive end-expiratory pressure to ventilation through the dependent lumen of a double-lumen tube and occluding the upper lumen of the tube will
- (A) increase blood flow to the dependent lung
- (B) increase the alveolar-arterial oxygen tension difference
- (C) override hypercarbic pulmonary vasoconstriction
- (D) improve the patient's oxygenation
- (E) increase the right ventricular dP/dt