| Popis: |
Largely on the basis of postmortem studies, pulmonary emboli have been implicated as an etiologic factor in the acute and chronic respiratory failure of chronic obstructive pulmonary disease (COPD). The diagnosis of pulmonary embolism clinically or by tests directed at the lungs (except pulmonary angiography) is likely to be inaccurate in the presence of COPD because of the underlying abnormalities. We reasoned that by directing tests at the lower extremities to determine the presence or absence of deep venous thrombosis (DVT), we might obtain an accurate reflection of the presence of pulmonary emboli (PE), since virtually all PE are believed to arise in those deep veins. Accordingly, in a group of 45 patients with decompensated COPD, we performed ascending contrast venography (12 patients), 125I-labeled fibrinogen scanning (6 patients), or both (27 patients). Only 2 patients had proximal DVT, which was probably present on admission (4.4%). Two other patients developed DVT (limited to the calf) while hospitalized, (overall incidence of 8.9%). Another patient developed superficial thrombophlebitis during the study but before venography. Noninvasive tests for DVT (Doppler ultrasound and impedance plethysmography) were performed in 40 subjects. A negative result had a high predictive value (94% for each), but contrary to findings in other settings, a positive test had a poor predictive value (Doppler = 33%, IPG = 25%). |
