Of the common causes for exudative pleural effusions, parapneumonic effusions have the highest diagnostic priority. Even in the face of antibiotic therapy, infected pleural effusions can rapidly coagulate and organize to form fibrous peels that might require surgical decortication.
Retrogradation is the landward change in position of the front of a river delta with time.etrogradation is the landward change in position of the front of a river delta with time.
3. a retrograde change of the entire body or in a particular organ, as the retrograde changes in the female genital organs that result in normal size after delivery. 4. the progressive degeneration occurring naturally with advancing age, resulting in shriveling of organs or tissues. uterine involution.