[Parapneumonic pleural effusion: an 11-year review]

In the last few years, the incidence of parapneumonic effusions in children with community-acquired pneumonia seems to have increased. The aim of this study was to determine the clinical features and incidence of parapneumonic effusions throughout an 11-year period.

We retrospectively reviewed the medical records of patients aged < 15 years old with parapneumonic effusions from 1993 to 2003. Annual incidence rates were calculated per 100,000 children < 15 years old from Health Area 5 of Madrid and per 100 children hospitalized in the Infectious Diseases Department of our hospital. The linear association test was used to compare the incidence rates over the previous 11 years.

There were 130 patients with parapneumonic pleural effusions. The mean age was 4.7 years. Forty-one percent received antibiotics before diagnosis. The causative organisms were identified in 42 patients (32.3%). The most effective diagnostic method was pleural-fluid culture (18/58, 31%). The most common organisms were Streptococcus pneumoniae (18), Mycoplasma pneumoniae (8), Staphylococcus aureus (4), Streptococcus pyogenes (3), Haemophilus influenzae (3) and Mycobacterium tuberculosis (2). Thirty-two percent of the patients required pleural drainage and 16% underwent video-assisted thoracoscopic surgery. Of 12 S. pneumoniae antibiograms available, 91.7% showed full susceptibility to penicillin and 75% were susceptible to erythromycin. The annual incidence of parapneumonic effusions rose from 18.1 in 1993 to 42.9 in 2003 (p < 0.001) per 100,000 children and from 0.76 in 1993 to 3.3 in 2003 (p < 0.001) per 100 children hospitalized in our unit.

The incidence of parapneumonic effusions in children with community-acquired pneumonia showed a statistically significant increase between 1993 and 2003. The most common causal organism was S. pneumoniae, with a low rate of penicillin resistance.