title: Does pleural fluid appearance really matter? The relationship between fluid appearance and cytology, cell counts, and chemical laboratory measurements in pleural effusions of patients with cancer.
abstract: BACKGROUND
  Previous reports have suggested that the appearance of pleural effusions (i.e., the presence or absence of blood) might help to establish the etiology of the effusions. This study explores the relationship between pleural fluid appearance and the results of chemical and cytological analyses in a group of patients with recurrent symptomatic pleural effusions and a diagnosis of cancer.
  
  
  METHODS
  Medical records were reviewed from all 390 patients who were diagnosed with cancer, who underwent thoracentesis before placement of an intrapleural catheter (IPC) between April 2000 and January 2006. Adequate information for data analysis was available in 365 patients. The appearance of their pleural fluid was obtained from procedure notes dictated by the pulmonologists who had performed the thoracenteses. The patients were separated into 2 groups based on fluid appearance: non-bloody and bloody. Group differences in cytology interpretation were compared by using the chi square test. Cellular counts, chemical laboratory results, and survival after index procedure were compared by using the student's t test.
  
  
  RESULTS
  Pleural fluid cytology was positive on 82.5% of the non-bloody effusions and on 82.4% of the bloody ones. The number of red blood cells (220.5 x 103/microL vs. 12.3 x 103/microL) and LDH values (1914 IU/dl vs. 863 IU/dl) were statistically higher in bloody pleural effusions.
  
  
  CONCLUSIONS
  The presence or absence of blood in pleural effusions cannot predict their etiology in patients with cancer and recurrent symptomatic pleural effusions.
authors: Department of Pulmonary Medicine, The University of Texas M, D, Anderson Cancer Center, Houston, TX, 77030-4008, USA. cajimenez@mdanderson.org
authors: Bulent
authors: B
authors: Ozcakar
authors: Carlos H
authors: CH
authors: Martinez
authors: Rodolfo C
authors: RC
authors: Morice
authors: Georgie A
authors: GA
authors: Eapen
authors: David
authors: D
authors: Ost
authors: Mona G
authors: MG
authors: Sarkiss
authors: Hsienchang T
authors: HT
authors: Chiu
authors: Carlos A
authors: CA
authors: Jimenez
mesh_terms: D000368:Aged; D015505:Chest Tubes; D003430:Cross-Sectional Studies; D005260:Female; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000503:physiopathology; D016066:Pleural Effusion, Malignant / Q000737:chemistry / Q000209:etiology* / Q000473:pathology; D013907:Thoracostomy / Q000379:methods