Pulmonology Book

http://www.fpnotebook.com/

Pleural Fluid

Aka: Pleural Fluid, Pleural Fluid Examination, Thoracentesis Interpretation, Transudate Pleural Effusion Findings, Exudate Pleural Effusion Findings, Empyema Pleural Effusion Findings, Bloody Pleural Effusion Findings
  1. See Also
    1. Pleural Effusion
    2. Pleural Effusion Causes
    3. Thoracentesis
  2. Indications
    1. Evaluation of Pleural Effusion
  3. Evaluation
    1. Based on fluid obtained during Thoracentesis
    2. Initial labs: Differentiate transudate from exudate
      1. See exudate interpretation below
      2. Light's criteria for Exudate
        1. Pleural Fluid protein to Serum Protein ratio >0.5
        2. Pleural Fluid LDH to serum LDH ratio >0.6
        3. Pleural Fluid LDH > 0.67 x serum LDH upper limit of normal
      3. Lactate Dehydrogenase (LDH)
        1. Pleural LDH
        2. Serum LDH
      4. Protein
        1. Serum Protein
        2. Pleural protein
    3. Initial labs: Identify cause (especially exudate)
      1. Pleural Fluid labs (in addition to pleural LDH and pleural protein as above)
        1. Pleural cell count with differential
        2. Pleural Gram Stain and culture
        3. Pleural Fluid cytology (Test Sensitivity: 60%)
          1. False negatives in Mesothelioma, Sarcoma, Lymphoma
          2. Consider repeat Thoracentesis if non-diagnostic
        4. Pleural Cholesterol (see exudate findings below)
        5. Pleural Hematocrit
          1. Pleural Hematocrit >1%
            1. Consistent with Pneumonia, Pulmonary Embolism, cancer or Trauma
          2. Pleural Hematocrit > (Blood Hematocrit x 0.5)
            1. Consistent with Hemothorax
        6. Pleural pH
          1. Pleural pH < 7.20
            1. Parapneumonic Effusion or empyema
          2. Pleural pH <7.30
            1. Malignant effusion, connective tissue disease, Esophageal Perforation
        7. Pleural Glucose <60 mg/dl (Parapneumonic Effusion or empyema)
      2. Pleural Fluid gross exam
        1. Bilious fluid
          1. Cholothorax from biliary fistula
        2. Black fluid
          1. Aspergillus infection
        3. Brown fluid
          1. Ruptured amoebic abscess
        4. Food particulate matter
          1. Esophageal Rupture or perforation
        5. Milky fluid
          1. Chylothorax or pseudochylothorax
        6. Foul odor
          1. Anaerobic empyema
        7. Urine
          1. Urinothorax
      3. Other labs (as indicated)
        1. Serum Cholesterol and Serum Triglycerides
        2. NT-proBNP (suggests CHF if >1500 pg/ml)
        3. Urine Protein (Nephrotic Syndrome)
        4. Thyroid Stimulating Hormone or TSH (Hypothyroidism)
    4. Other labs: Infection suspected
      1. PCR for Streptococcus Pneumoniae
      2. Infection suspected despite non-purulent fluid
        1. Pleural Fluid pH
      3. Tuberculosis suspected
        1. Adenosine deaminase
          1. Sensitive and specific for Tuberculosis at >90%
          2. Can also be elevated in cancer and empyema
        2. Interferon (alternative to Adenosine deaminase)
        3. PCR for Mycobacterium tuberculosis
        4. Culture for Mycobacterium tuberculosis
        5. Acid Fast Bacillus (AFB) smears are rarely positive
    5. Other labs: Cancer suspected
      1. Tumor Markers
        1. Carcinoembryonic Antigen
        2. Cancer Antigen 125
        3. Cancer antigen 15-3
        4. Cytokeratin 19 fragment
        5. Mesothelin
      2. Pleural amylase (Cancer, Pancreatitis, Esophageal Perforation, Tuberculosis)
      3. Triglycerides (Lymphoma, Trauma)
  4. Findings: Transudate
    1. See Transudate Pleural Effusion Causes
    2. Clear fluid
    3. Protein < 3 g/dl
    4. Lactate Dehydrogenase (LDH) <200 IU/L
    5. Glucose >60 mg/dl
    6. White Blood Cell Count < 1000/ml
  5. Findings: Exudate
    1. See Exudate Pleural Effusion Causes
    2. False positive in CHF after Diuretics
      1. Correction for Diuretics: Serum Protein - Pleural protein >3.1 g/dl
      2. Correction for Diuretics: Serum Albumin - pleural albumin >1.2 g/dl
    3. Clear, cloudy or bloody fluid
    4. Protein
      1. Pleural protein > 3 g/dl
      2. Pleural protein to Serum Protein ratio >0.5
    5. Lactate Dehydrogenase
      1. Pleural LDH > 200 IU/L
      2. Pleural LDH > 2/3 serum LDH upper normal limit
      3. Pleural LDH to serum LDH ratio >0.6
    6. Glucose < 60 mg/dl
    7. White Blood Cell Count > 1,000/ml
    8. Pleural Cholesterol
      1. Pleural Cholesterol >55 mg/dl
      2. Pleural Cholesterol to serum Cholesterol ratio > 0.3
  6. Findings: Empyema
    1. See Empyema Pleural Effusion Causes
    2. White Blood Cell Count > 10,000 cells/cu mm
    3. Gram Stain
    4. Pleural Fluid culture positive
    5. Glucose > 40 mg/dl
    6. pH < 7.2
    7. Additional tests to consider when infection suspected
      1. Consider PCR for Streptococcus Pneumoniae
      2. Tuberculosis Testing is described above
  7. Findings: Uniformly bloody effusion
    1. See Bloody Pleural Effusion Causes
    2. Fluid Hematocrit >1% (Hemothorax if >50% Hematocrit)
    3. Red Blood Cell Count >100,000 per mm3
  8. References
    1. Hooper (2010) Thorax 65(suppl 2): ii4-17 [PubMed]
    2. Light (2002) N Engl J Med 346:1971-7 [PubMed]
    3. Medford (2005) Postgrad Med J 81 (961):702-10 [PubMed]
    4. Porcel (2006) Am Fam Physician 73:1211-20 [PubMed]
    5. Rabman (2005) Br Med Bull 72:31-47 [PubMed]
    6. Saguil (2014) Am Fam Physician 90(2): 99-104 [PubMed]

You are currently viewing the original 'fpnotebook.com\legacy' version of this website. Internet Explorer 8.0 and older will automatically be redirected to this legacy version.

If you are using a modern web browser, you may instead navigate to the newer desktop version of fpnotebook. Another, mobile version is also available which should function on both newer and older web browsers.

Please Contact Me as you run across problems with any of these versions on the website.

Navigation Tree