Introduction: The aim of this prospective, originally designed, clinical--diagnostic study including 200 chronic hypoxemic patients was to assess the possibility of implementation of noninvasive diagnostic strategy and to investigate the incidence of pulmonary embolism and parameters of diagnostic accuracy of radiological findings according to Shintz criteria, echocardiography, lung perfusion scanning according to PIOPED criteria.
Material and methods: The study included 200 chronic hypoxemic patients divided into 2 groups, the group I consisting of 42 women and 58 men and the group II consisting of 48 women and 52 men.
Results and conclusion: Out of 200 hypoxemic patients, 49 patients (24.5%) were found to have pulmonary embolism. In the group I of 100 patients (42 women and 58 men) with chronic hypoxemia and secondary erythrocytosis the diagnosis of pulmonary embolism was confirmed in 39%, that being statistically significantly different (p < 0.001) from 100 patients (48 women and 52 men) in the group II with chronic hypoxemia without secondary erythrocytosis, where pulmonary embolism was found in 10% of the patients. The predictive value was positive for direct radiological signs in 92.3% of patients in the group I for PTE, for indirect ones in 74.35%, and in the group II it was positive for direct radiological signs in 60% and for indirect ones in 90%. The predictive value of perfusion scan was positive in 59% of the group I and in only 22% of the group II. The predictive value for high pressure in the pulmonary artery was positive in 93.7% of the group I and in 66.6% of the group II. The following were found to be a variable predictor: hypoxemia, enlargement of the pulmonary artery, peripheral oligemia and elevation of diaphragm. Logistic regression according to backward--conditional method showed that the chronic hypoxemic patients with secondly erythrocytosis, who had radiological sign of peripheral oligemia--Westermark sign, had 2.286 times higher probability of having pulmonary embolism than similar patients without this sign.