"Failure to wedge" and pulmonary hypertension during pulmonary artery catheterization: a sign of totally occlusive pulmonary embolism.

Correctly diagnosing pulmonary embolism in the ICU can be very difficult, especially when cardiopulmonary disease is coexistent but unrelated. This study describes four hemodynamically unstable patients in whom pulmonary hypertension and an inability to obtain a wedge pressure during balloon flotation catheterization suggested total embolic occlusion of a major pulmonary artery segment distal to the catheter. The diagnosis was confirmed by angiography performed via the flotation catheter in three patients, and by a perfusion scan in one patient. Streptokinase was infused directly into the pulmonary artery of two patients, resolving the pulmonary hypertension and occlusion in both.