title: Factors influencing length of hospital stay in patients with bacterial pleural effusion.
abstract: BACKGROUND
  Factors influencing length of hospital stay have been poorly analyzed in parapneumonic pleural effusions (PPE).
  
  
  OBJECTIVE
  The aim of this work is to identify the variables that determine increased hospital stay in patients with infectious pleural effusion (PE).
  
  
  METHODS
  We analyzed 112 patients with PE: empyema, complicated parapneumonic and non-complicated parapneumonic. Epidemiologic, biochemical, therapeutic and radiological variables were analyzed. Correlations with hospital stay were studied using the Student's t test, analysis of variance, Mann-Whitney U-test and linear regression model.
  
  
  RESULTS
  Among the 112 patients studied, there were 32 empyema, 50 complicated and 30 non-complicated parapneumonic cases. The median of length stay for all patients was 17 days. Longer hospitalization was required in patients with empyemic PE (p = 0.015), patients with underlying diseases (p = 0.003), those needing pleural drainage (p = 0.005) or decortication (p = 0.043) and those presenting unfavorable radiological outcome after treatment (p = 0.02). Biochemical parameters associated with longer hospital stay were elevated pleural fluid polymorphonuclear elastase (p = 0.001, r = 0.307) and lactate dehydrogenase (p = 0.001, r = 0.312). After linear regression analysis, only underlying disease, pleural drainage and pleural fluid polymorphonuclear elastase values remained in the model, explaining 23.1% of the variability of days of hospitalization.
  
  
  CONCLUSIONS
  The patients with PPE and empyema who required longer hospitalization were those with purulent fluid, underlying disease, surgical drainage and/or decortication, with unfavorable radiological outcome and higher pleural fluid levels of lactate dehydrogenase and polymorphonuclear elastase.
authors.affiliation: Department of Internal Medicine, Vall d'Hebrón General Teaching Hospital, Mare de Deu dels Angels 50-54, 5o-9a, ES-08035 Barcelona, Spain. 32948tss@comb.es
authors.forename: T
authors.initials: T
authors.lastname: Soriano
authors.forename: J
authors.initials: J
authors.lastname: Alegre
authors.forename: C
authors.initials: C
authors.lastname: Alemán
authors.forename: E
authors.initials: E
authors.lastname: Ruiz
authors.forename: A
authors.initials: A
authors.lastname: Vázquez
authors.forename: J L
authors.initials: JL
authors.lastname: Carrasco
authors.forename: R
authors.initials: R
authors.lastname: Segura
authors.forename: A
authors.initials: A
authors.lastname: Ferrer
authors.forename: T
authors.initials: T
authors.lastname: Fernández de Sevilla
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D016724:Empyema, Pleural / Q000150:complications; D045604:Extracellular Fluid / Q000378:metabolism; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D018410:Pneumonia, Bacterial / Q000150:complications
chemical_list: D015415:Biomarkers