title: Effects of diuresis on the characteristics of pleural fluid in patients with congestive heart failure.
abstract: OBJECTIVE
  The pleural fluid that accumulates secondary to congestive heart failure is almost always a transudate based upon its level of protein and lactic acid dehydrogenase (LDH). Previous work has suggested that the characteristics of the fluid may change into those of an exudate with diuresis. The purpose of the present study was to determine whether aggressive diuresis does result in this change in pleural fluid characteristics.
  
  
  METHODS
  Twelve patients with severe congestive heart failure (ejection fraction 23.9 +/- 9.6%) and pleural effusions were studied serially as they underwent diuresis. After an initial thoracentesis was performed, the patients then underwent aggressive diuresis for 12 to 48 hours with one or two follow-up thoracentesis.
  
  
  RESULTS
  The mean weight loss during the study period was 4.5 +/- 2.8 kg. With diuresis the LDH level, LDH ratio, protein level, and protein ratio all increased significantly (p less than 0.05). All 12 patients had transudative pleural effusions at the onset of diuresis. However, despite the increases in the levels of protein and LDH with diuresis, only one patient's pleural fluid attained values compatible with an exudate.
  
  
  CONCLUSIONS
  From this study we conclude that it is uncommon for a transudative pleural effusion due to congestive heart failure to develop the characteristics of an exudative pleural effusion with rapid diuresis.
authors.affiliation: Department of Medicine, Veterans Administration Medical Center, Long Beach, California 90822.
authors.forename: R A
authors.initials: RA
authors.lastname: Shinto
authors.forename: R W
authors.initials: RW
authors.lastname: Light
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000032:analysis; D004231:Diuresis; D005122:Exudates and Transudates / Q000201:enzymology / Q000502:physiology; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D010996:Pleural Effusion / Q000503:physiopathology*; D011506:Proteins / Q000032:analysis
chemical_list: D011506:Proteins; D003404:Creatinine; D007770:L-Lactate Dehydrogenase