TO STUDY the effect of parenteral administration of oxygen on unanesthetized cyanotic dogs, the construction of a right to left pulmonary blood shunt was undertaken in 1947. A satisfactory procedure was developed consisting of left pneumonectomy and anastomosis of the left pulmonary artery to the pulmonary vein of the left lower lobe through a graft. This procedure has not proved satisfactory for oxygen studies because of the frequency of fatal paradoxical oxygen embolism. These shunts are reliably large, however, and venous catheterization of the left heart is readily accomplished through them. The method devised is suitable for physiological studies of chronic cyanosis, right and left heart pressures, intracardiac electrocardiography, and left heart cinefluorography. It is for these reasons that it is reported.
Mongrel dogs weighing 13 to 30 kg. were anesthetized with pentobarbital sodium (nembutal®) intravenously and given positive pressure respiration with air or oxygen. The chest was entered