Pleural Effusions in the Pediatric Population

Abstract

1. Ori Efrati, MD* 2. Asher Barak, MD* 1. *The Pediatrics Pulmonary Unit, Sheba Medical Center, Tel HaShomer Hospital, Ramat Gan, Israel After completing this article, readers should be able to: 1. Describe the anatomic pleural cavity. 2. Delineate the most likely causes for pediatric pleural effusions. 3. Distinguish between exudate and transudate. 4. Describe the diagnostic radiographic and laboratory examinations for pleural effusions. 5. Describe the management of parapneumonic effusion. 6. Describe other types of pleural effusions. Pleural effusions (liquid in the pleural space), which occur less frequently in children than in adults, can be caused by a variety of infectious and noninfectious diseases. Most of the information about pleural effusions is derived from adult studies. Causes of pleural effusions in children differ significantly from those in adults. Among adults, the most frequent cause is congestive heart failure (transudate), and bacterial pneumonia and malignancy are the most frequent causes of exudate. Pleural effusions in children most commonly are infectious (50% to 70% parapneumonic effusion); congestive heart failure is a less frequent cause (5% to 15%), and malignancy is a rare cause. Parapneumonic effusion is defined as fluid in the pleural space in the presence of pneumonia, lung abscess, or bronchiectasis. Nontuberculous bacterial pneumonia constitutes the most frequent origin of pleural effusion in children. Establishing a specific causative agent depends on the patient’s age, underlying disease, standard of laboratory culture method, and initiation of antibiotic therapy. Staphylococcus aureus is the single most common pathogen causing empyema (29% to 35% of cases), especially among infants younger than 2 years of age. Streptococcus pneumoniae is the cause in up to 25% of cases of empyema. Haemophilus influenzae is a less frequent pathogen but still is significant in the development of parapneumonic effusion in children up to 5 years of age. Group A streptococci have re-emerged as significant agents causing empyema in later childhood. Anaerobic pulmonary infection is uncommon, and more than 90% of affected patients manifest periodontal infections, altered consciousness, …