title: A comparison of induced and expectorated sputum for the microbiological diagnosis of community acquired pneumonia.
abstract: BACKGROUND
  Sputum induction has proved useful in the diagnosis of Pneumocystis carinii pneumonia and mycobacterial infections but there are scant data on its use in the diagnosis of community-acquired pneumonia (CAP).
  
  
  OBJECTIVE
  To better define the usage of sputum induction by hypertonic saline in the setting of CAP.
  
  
  METHODS
  A retrospective review of records of patients admitted to a community teaching hospital in the year 1995 with a diagnosis of CAP.
  
  
  RESULTS
  Of 492 patients admitted with CAP, 71 (14%) had attempted sputum induction. A group of 66 patients with CAP and attempted sputum collection by spontaneous expectoration was compared with this group. Sputum induction failed to yield a sample in 22 patients (31%). Forty-five of 49 patients (92%) with induced sputum had received prior antibiotics as compared to 23 of 34 patients (68%) with expectorated samples (p < 0.05), due to sputum induction often being attempted later in the hospital course. The diagnostic yield of sputum induction was 14 of 71 (20%) compared to 16 out of 66 (24%) for attempted spontaneously expectorated samples. Antibiotic therapy was changed for 5 of 34 patients (15%) who spontaneously expectorated samples and for 9 of 49 patients (18%) with successful induction.
  
  
  CONCLUSIONS
  Sputum induction is effective in obtaining sputum in some patients with CAP who fail to expectorate a sample. Attempting induction early, preferably before starting antibiotics, may increase its diagnostic yield.
authors.affiliation: Pulmonary Division, University of Connecticut School of Medicine, Farmington, Conn., USA.
authors.forename: T
authors.initials: T
authors.lastname: Bandyopadhyay
authors.forename: D A
authors.initials: DA
authors.lastname: Gerardi
authors.forename: M L
authors.initials: ML
authors.lastname: Metersky
mesh_terms: D000280:Administration, Inhalation; D000368:Aged; D001419:Bacteria / Q000302:isolation & purification; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000382:microbiology; D003237:Connecticut; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D008297:Male; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000382:microbiology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012965:Sodium Chloride / Q000008:administration & dosage; D013183:Sputum / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D012965:Sodium Chloride