[Hypovolemic shocks simulating severe pulmonary embolism. 20 cases].

Twenty cases of hypovolemic shock of various etiologies in which initial diagnosis was massive pulmonary embolism are analyzed. The error was due to intensity of respiratory failure symptoms and electrocardiographic changes suggesting acute cor pulmonale. However, although constant, hypoxemia was mild and easily corrected by oxygen administration. Hypovolemia was confirmed by low central venous pressure (CPV EQUALS 1, 3 cm H20); in 7 patients, right heart catheterism showed lowered cardiac output associated to low ventricular filling pressures (VFP). Rapid blood volume expansion simultaneously corrected in all cases both shock and clinical signs of "respiratory failure", while CVP increased only slightly. These findings suggest that CVP must be carefully checked when faced with a clinical picture of massive pulmonary embolism and if low, rapid blood volume expansion must be performed under CVP monitoring, in order to rule out hypovolemic shock.