SEGMENTAL PULMONARY ANGIOGRAPHY IN THE CRITICALLY-ILL PATIENT USING A FLOW-DIRECTED CATHETER

Selective pulmonary angiography was performed using a flow-directed, balloon-tipped catheter in 20 consecutive intensive care unit patients requiring heart catheterizations on the right side for hemodynamic monitoring. No morbidity was encountered from this procedure. Adequate quality balloon-occlusion angiographs were obtained with a portable chest roentgenogram in 17 (85%) but appeared normal in only 12 (60%), seriously limiting the usefulness of this technique in the diagnosis of occult pulmonary embolisms. The catheter tip was in a segmental pulmonary artery anterior to the left atrium (zone I) in 30% of the patients. The catheter tip was not infrequently situated in zone I anterior to the left atriums. Selective pulmonary angiography using a flow-directed, balloon-tipped catheter proved useful in demonstrating the precise location of the catheter tip. When this is the case, the catheter tip should be relocated to a segment below the left atrium (zone III) in patients requiring positive end-expiratory pressure because the wedge pressure measured in zone I may not accurately reflect left atrial pressure.