helpsimple searchclear selectionselect all
Dictionary assisted search
All words
Any word/input
Exact phrase
in these
lexical topics:
  • Physics, Techniques and Procedures
  • Normal Anatomy
  • Musculoskeletal Imaging
  • Breast Imaging
  • Gastrointestinal Imaging
  • Urogenital Imaging
  • Chest Imaging
  • Cardiovascular Imaging
  • Neuroradiology
  • Head and Neck Imaging
  • Paediatric Imaging
 
 
 
Chest Imaging

Parapneumonic effusion

pleural effusion occurring in association with bacterial pneumonia. The incidence varies with the infecting organism from about 10% in streptococcal pneumonia to over 50% in pneumonia caused by Staphylococcus pyogenes. Inflammation of the pleura by the adjacent infection results in increased capillary permeability and exudation of fluid into the pleural space. Initially the pleural fluid is sterile, has a low white cell count, a low lactate dehydrogenase (LDH), and normal glucose and pH levels. Appropriate treatment of the underlying pneumonia should result in resolution of such uncomplicated parapneumonic effusions without the need for drainage.

Without antibiotic therapy the effusion becomes fibropurulent or complicated and is characterized by a positive culture, raised white cell count, LDH and glucose, and low pH level. Such effusions require tube drainage.

Simple parapneumonic effusions appear on the chest radiograph and on ultrasound as a free flowing effusion. Complicated parapneumonic effusions often become loculated and may assume a lenticular or other bizarre shape on the chest radiograph. Chest ultrasonography reveals fibrous septa within the fluid.

CF - HM