Dynamics of CT visible pleural effusion in patients with pulmonary infarction

Background Pleural effusion remains largely unexplored in patients with pulmonary embolism and concurrent pulmonary infarction. The aim of the study was to investigate the relationship between the size of pulmonary infarction and pleural effusion as well as the time course of pleural effusion in patients with pulmonary infarction. Patients and methods Data from 103 patients with pulmonary infarction was retrospectively analysed along with patient comorbidities, size of pulmonary infarction, presence and size of pleural effusion with the time between the onset of clinical symptoms of pulmonary infarction and CT study. Results Assessment of possible correlations between the size of pulmonary infarction and age revealed a significant negative correlation. There was a highly significant difference (p = 0.005) in the mean size of pulmonary infarction in patients with effusion (34.5 cm3) compared to those without it (14.3 cm3), but the size of the effusion had no correlation with the size of pulmonary infarction. The size of the effusion peaked between 4th-5th day after the onset of clinical symptoms of pulmonary infarction. In the first 5 days after the onset of clinical symptoms of pulmonary infarction a significant correlation was found between the size of the effusion and time with approximation of 1.3 mm/12 h. Conclusions The data shows that patients with a pleural effusion are more likely to have a larger pulmonary infarction than those without it. If present, the effusion can be expected to increase in a relatively slow linear fashion in the first 5 days after the onset of clinical symptoms of pulmonary infarction.