title: Influence of previous use of inhaled corticoids on the development of pleural effusion in community-acquired pneumonia.
abstract: BACKGROUND
  Previous use of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease has been associated with increased risk of community-acquired pneumonia. However, ICS have been associated with fewer pneumonia complications and decreased risk of pneumonia-related mortality.
  
  
  OBJECTIVE
  The objective of the study was to assess the influence of previous use of ICS on the incidence of parapneumonic effusion in patients with different baseline respiratory disorders.
  
  
  METHODS
  We conducted a single-center cohort study of 3,612 consecutively collected patients diagnosed with community-acquired pneumonia. We assessed clinical, radiographic, and pleural-fluid chemistry and microbiologic variables. Patients were classified according to whether or not they received prior ICS treatment.
  
  
  RESULTS
  A total of 633 patients (17%) were treated with corticosteroids before the diagnosis of pneumonia (chronic obstructive pulmonary disease, 54%; asthma, 13%). Incidence of parapneumonic effusion was lower in patients with ICS use compared with non-ICS patients (5% vs. 12%; P < 0.001). After matching according to propensity scores (n = 640), prior treatment with corticosteroids was still significantly associated with a lower incidence of parapneumonic effusion (odds ratio, 0.40; 95% confidence interval, 0.23-0.69; P = 0.001) compared with patients without ICS treatment. Prior ICS treatment was associated with higher levels of glucose (P = 0.003) and pH (P = 0.02), and lower levels of protein (P = 0.01) and lactic acid dehydrogenase (P = 0.007) in the pleural fluid.
  
  
  CONCLUSIONS
  Prior treatment with ICS in a population of patients with different respiratory chronic disorders who develop pneumonia is associated with lower incidence of parapneumonic effusion.
authors.affiliation: Servei de Pneumologia, Institut del Torax, Hospital Clínic, Institut d'Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain.
authors.forename: Jacobo
authors.initials: J
authors.lastname: Sellares
authors.forename: Alejandra
authors.initials: A
authors.lastname: López-Giraldo
authors.forename: Carmen
authors.initials: C
authors.lastname: Lucena
authors.forename: Catia
authors.initials: C
authors.lastname: Cilloniz
authors.forename: Rosanel
authors.initials: R
authors.lastname: Amaro
authors.forename: Eva
authors.initials: E
authors.lastname: Polverino
authors.forename: Miquel
authors.initials: M
authors.lastname: Ferrer
authors.forename: Rosario
authors.initials: R
authors.lastname: Menéndez
authors.forename: Josep
authors.initials: J
authors.lastname: Mensa
authors.forename: Antoni
authors.initials: A
authors.lastname: Torres
mesh_terms: D000280:Administration, Inhalation; D000368:Aged; D001249:Asthma / Q000188:drug therapy; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D010996:Pleural Effusion / Q000139:chemically induced* / Q000453:epidemiology; D011014:Pneumonia / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology
chemical_list: D005938:Glucocorticoids