ANESTHETIC MANAGEMENT OF PATIENTS UNDERGOING BILATERAL UNIFOCALIZATION

We report on the anesthetic management of eight patients undergoing unifocalization for pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries. Unifocalization was performed separately on the right and left lungs in the lateral decubitus position. During unifocalization, pulmonary blood flow to the nondependent lung is interrupted and arterial oxygenation is dependent solely on the blood flow to the dependent lung. Thus, PaO2 and SaO2 decreased significantly and PaCO2 increased significantly during unifocalization, as compared with before and after unifocalization. When these values are compared between first and second stage of unifocalization, SaO2 during second stage was lower than during first stage. Although PaO2, PaCO2, and pH during second stage tended to be worse than during first stage, the differences did not reach statistical significance. During unifocalization, especially in second stage, to prevent deterioration of these arterial gas variables, pulmonary blood flow had to be increased by frequent administration of catecholamine. In addition, bicarbonate infusion was also used to prevent progressive metabolic acidosis due to hypoxia during unifocalization. Because anticoagulant therapy was required during unifocalization, airway bleeding was a common complication.