title: Pleural fluid pH in malignant effusions. Diagnostic, prognostic, and therapeutic implications.
abstract: OBJECTIVE
  To determine whether the measurement of pleural fluid pH in malignant effusions has diagnostic use, predicts survival, and has therapeutic implications.
  
  
  METHODS
  A prospective comparison of cytologic examinations and pleural biopsy results, survival, and response to chemical pleurodesis with tetracycline in patients with normal-pH (7.30 or greater) and low-pH (less than 7.30) malignant pleural effusions.
  
  
  METHODS
  Academic medical center, university referral hospital, city hospital, and Veterans Administration hospital.
  
  
  METHODS
  Sixty patients with malignant pleural effusions, proven at either initial thoracentesis by cytologic examination or within 4 months of initial thoracentesis by repeat thoracentesis, thoracotomy, or autopsy, were followed until death.
  
  
  METHODS
  Twenty-one patients, 12 with normal pleural fluid pH and 9 with low pleural fluid pH, were treated with tube thoracostomy and intrapleural tetracycline for symptomatic, recurrent pleural effusions.
  
  
  RESULTS
  The 20 patients with low-pH malignant effusions had a significantly greater positivity on initial pleural fluid cytologic evaluation, a shorter mean survival, and a poorer response to tetracycline pleurodesis compared with 40 patients with normal-pH malignant effusions.
  
  
  CONCLUSIONS
  Determination of pleural fluid pH in malignant effusions provides a rational approach to further diagnostic testing, prognostic information, and a rationale for palliative treatment.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Medical University of South Carolina, Charleston.
authors.forename: S A
authors.initials: SA
authors.lastname: Sahn
authors.forename: J T
authors.initials: JT
authors.lastname: Good
mesh_terms: D003581:Cytodiagnosis; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D010996:Pleural Effusion / Q000209:etiology / Q000378:metabolism* / Q000628:therapy; D011379:Prognosis
chemical_list: D007770:L-Lactate Dehydrogenase; D005947:Glucose