Pleura

Pleural Effusion

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Pleural Effusion, Thoracic Effusion

  • See Also
  1. Pleural Effusion Causes
  2. Thoracentesis
  3. Pleural Fluid Interpretation
  4. Medication Causes of Pleural Effusion
  • Definitions
  1. Pleural Effusion
    1. Fluid accumulation within the pleural cavity
  2. Parapneumonic Effusion
    1. Infectious cause of Pleural Effusion (e.g. Pneumonia, Lung Abscess)
  3. Pleural Empyema
    1. Parapneumonic Effusion complicated by pustular infection
  • Epidemiology
  1. Pleural Effusions are diagnosed in up to 1.5 million hospitalized U.S. patients per year (<10% are malignant)
  • Causes
  1. See Pleural Effusion Causes
  2. See Medication Causes of Pleural Effusion
  • Pathophysiology
  1. Physiologic levels of fluid (5 to 10 ml) may be found normally in the pleural space, providing lubrication between layers
  2. Pleural Fluid accumulates when fluid production out paces absorption
  3. Transudates develop from disrupted hydrostatic or oncotic pressures (e.g. CHF, Cirrhosis, ESRD)
  4. Exudates form from inflammation and infection
  • History
  1. Active medical history
    1. Congestive Heart Failure
    2. Cirrhosis
    3. Renal Failure
    4. Malignancy (including Lung Cancer)
    5. Trauma
    6. Pneumonia
    7. Rheumatologic Disorder (Systemic Lupus Erythematosus, Rheumatoid Arthritis)
  2. Recent surgical history
    1. Coronary Artery Bypass Surgery
    2. Esophageal Surgery (Esophageal Perforation risk)
    3. Atrial Fibrillation Ablation (pulmonary vein stenosis risk)
    4. Ventriculoperitoneal Shunt (risk of shunt migration)
    5. Laparotomy
    6. Postpartum Period
  3. Exposures
    1. See Medication Causes of Pleural Effusion
    2. Fungal Lung Infection
    3. Asbestos Exposure
  • Symptoms
  1. Non-productive Cough
  2. Pleuritic Chest Pain
    1. Referred pain to ipsilateral Shoulder or Abdomen
  3. Tachypnea
  4. Low grade fever
  5. Dyspnea
    1. Trepopnea (Dyspnea worse when lying on one side)
  6. Red flags
    1. Weight loss
    2. Fever
      1. Low grade fever may be seen in non-infectious cause
    3. Hemoptysis
      1. Malignancy
      2. Tuberculosis
      3. Pulmonary Embolism
  • Signs
  • Findings suggestive of Pleural Effusion
  1. Findings assume Pleural Effusion >300 ml
    1. Smaller Pleural Effusions are unlikely to be found on physical examination alone
  2. Asymmetric chest expansion
    1. Test Sensitivity: 74%
    2. Test Specificity: 91%
    3. Positive Likelihood Ratio (LR+): 8.1
  3. Diminished or absent breath sounds over effusion
    1. Test Sensitivity: 42-88%
    2. Test Specificity: 83-90%
  4. Dullness to percussion over effusion
    1. Test Sensitivity: 30-90%
    2. Test Specificity: 81-98%
    3. Positive Likelihood Ratio (LR+): 8.7
  5. Decreased tactile fremitus on affected side
    1. Negative Likelihood Ratio (LR+): 0.21
  6. Decreased voice transmission on affected side (vocal fremitus)
    1. Test Sensitivity: 82%
    2. Test Specificity: 86%
  7. Decreased auscultatory percussion (tap manubrium while auscultating posteriorly)
    1. Test Sensitivity: 30-96%
    2. Test Specificity: 84-95%
  8. Pleural friction rub
    1. Test Sensitivity: 5.3%
    2. Test Specificity: 99%
  9. References
    1. Wong (2009) JAMA 301(3):309-17 [PubMed]
  • Signs
  • Pleural Effusion cause-specific examination
  1. Constitutional
    1. Fever (Pneumonia, empyema, Tb, malignancy, abdominal abscess)
  2. Pulmonary
    1. Hemoptysis (malignancy, PE, Tb)
  3. Cardiovascular
    1. Increased Jugular Venous Pressure (CHF, Pericarditis)
    2. Orthopnea (CHF)
    3. Bilateral Lower Extremity Edema (CHF)
    4. Unilateral extremity edema (Venous Thromboembolism)
    5. Pericardial Friction Rub (Pericarditis)
    6. S3 Gallop rhythm (CHF)
  4. Abdomen
    1. Hepatomegaly or Splenomegaly (CHF, malignancy)
    2. Ascites, Jaundice, Spider Angioma, asterixis (Cirrhosis)
  5. Hemeonc
    1. Lymphadenopathy (malignancy)
    2. Primary cancer site (Breast, colon, Prostate, skin)
    3. Weight loss (malignancy)
  6. Musculoskeletal
    1. Joint exam for arthritic changes (Rheumatoid Arthritis)
  1. Indications
    1. Effusion not explained by Congestive Heart Failure, Renal Failure or liver failure
      1. Effusions that persist despite diuresis, Dialysis or other specific treatment
      2. Avoid Thoracentesis for suspected transudative small bilateral Pleural Effusions
        1. CHF Causes more than a third of all Pleural Effusions (esp. bilateral, right >left)
    2. Undiagnosed effusions large enough to aspirate
      1. Effusion >1 cm high on decubitus XRay in an undiagnosed patient
      2. Effusion >5 cm high on lateral XRay in Pneumonia patient (Parapneumonic Effusion, empyema)
      3. Ultrasound with pocket >1 cm (and no intervening tissue such as liver)
    3. Other indications
      1. Asymmetric or unilateral Pleural Effusions
      2. Fever
  2. Interpretation
    1. See Pleural Fluid Examination
    2. See Transudate Pleural Effusion Causes
    3. See Exudate Pleural Effusion Causes
    4. See Empyema Pleural Effusion Causes
  • Labs
  • Biopsy or Cytology Indications
  1. Exudate
  2. Malignancy suspected
  3. Mycobacterium tuberculosis suspected
    1. Especially if lymphocytic exudate
  • Imaging
  1. Chest XRay: (PA and Lateral decubitus)
    1. Indications
      1. First-line study in the evaluation of Chest Pain and Dyspnea
      2. Indicated to diagnose and monitor effusions
      3. Cannot differentiate transudate from exudate
      4. Lower lobe consolidation may make interpretation difficult
    2. Findings based on effusion size
      1. Small: Pleural fissure thickening, costophrenic angle blunting
      2. Moderate: Diaphragm obscured
      3. Large: Air-Fluid Level
      4. Very Large: Hemithorax opacification with midline shift
    3. Posteroanterior Chest XRay
      1. Pleural Effusion blunts the costophrenic angle
      2. Detects Pleural Effusion >200 ml
    4. Lateral Chest XRay
      1. Pleural Effusion appears as a meniscus-shaped, concave upward opacity
      2. Detects Pleural Effusion >50-75 ml
    5. Lateral decubitus XRay
      1. Pleural Effusion fluid layers out
      2. Better estimation of effusion size and whether it is loculated
      3. Detects Pleural Effusion 10 to 25 ml
    6. Other findings
      1. Loculated effusions D-Shaped appearance
  2. Lung Ultrasound
    1. See Lung Ultrasound
    2. More accurate than Chest XRay in detecting a Pleural Effusion (operator dependent)
      1. Detects Pleural Effusion volumes as small as 5 to 20 ml
      2. Distinguishes Pleural Effusions from consolidation and defines septations and loculations
      3. Test Sensitivity 94%, Test Specificity 98% (varies with operator experience)
      4. Limited by bullae (COPD), subcutaneous air, and tight rib spaces
    3. Identifies Pleural Fluid septations more accurately than CT
    4. Recommended for guiding Thoracentesis
    5. Soni (2015) J Hosp Med 10(12): 811-6 [PubMed]
  3. CT Chest
    1. Higher Test Sensitivity than Chest XRay in detecting Pleural Effusions
    2. Distinguishes between Pleural Effusion and pleural thickening
    3. Anatomic survey of chest and upper Abdomen may reveal clues to Pleural Effusion etiology
      1. See Pleural Effusion Causes
      2. Consider CTA Chest for Pulmonary Embolism (fourth leading cause of unilateral Pleural Effusion)
      3. Evaluate for Esophageal Rupture, mediastinal disorders, malignancy
  • Management
  • Acute
  1. Transudate or Exudate
    1. See Pleural Effusion Causes
    2. Treat the underlying pathology
    3. Suspected exudates typically require diagnostic Thoracentesis
    4. Eliminate Medication Causes of Pleural Effusion (transudate)
  2. Lung Empyema or Parapneumonic Effusion
    1. See Lung Empyema
    2. Thoracentesis is critical in complicated Parapneumonic Effusion or empyema
    3. Adequate drainage is the key to treatment
    4. Chest Tube Indications
      1. Fibropurulent or organized Pleural Effusions (will not respond to Antibiotic therapy alone)
      2. Pleural Fluid pH <7.2 or pustular fluid (empyema)
    5. Consider intrapleural fibronolytics (Streptokinase)
    6. Surgery Indications
      1. Inadequate Chest Tube drainage
  3. Malignancy suspected (unilateral Pleural Effusion)
    1. Most common causes include Lung Cancer, Breast Cancer and Leukemia
    2. CT-guided needle pleural biopsy
    3. Treat underlying malignancy
    4. Maskell (2003) Lancet 361:1326-30 [PubMed]
  4. Congestive Heart Failure
    1. See Congestive Heart Failure Exacerbation Management
    2. Avoid Thoracentesis unless large Pleural Effusion and Dyspnea
  5. Cirrhosis
    1. Fluid is typically due to Ascites that crosses a diaphragmatic defect
    2. Primary management is in reducing Cirrhotic Ascites
    3. Closure of diaphragmatic defect and pleurodesis is risky and not typically performed
  6. Pericarditis and other Pericardial Disease
    1. Complicates 25% of pericardial disease patients
    2. Presents with bilateral Pleural Effusions (but left > right)
    3. Example: Dressler's Syndrome
    4. Treat underlying conditon
  7. Milky White Pleural Fluid
    1. Empyema (pus)
      1. White fluid separates on centrifugation (clear supernatant and white cellular debris)
    2. Pseudochylothorax (Tuberculosis, rheumatoid pleuritis)
      1. Decreased Triglyceride <50 mg/dl (poor Test Sensitivity but excludes Chylothorax)
      2. Cholesterol crystals
    3. Migrated Central Venous Catheter infusing Total Parenteral Nutrition
    4. Chylothorax (due to lymph accumulation in chest)
      1. Caused by Cirrhosis, Nephrotic Syndrome, Lymphoma or often idiopathic
      2. Findings
        1. Increased Triglyceride >110 mg/dl,
        2. Chylomicrons
        3. Pleural to serum Cholesterol ratio <1
      3. Management
        1. Treat underlying condition
        2. Dietary modifications
        3. Repeat Thoracentesis
        4. Peritoneal venous shunt
        5. Indwelling pleural catheter (e.g. PleurX Catheter)
        6. Pleurodesis (refractory chylothorax in Lymphoma)
  8. Tuberculosis suspected (ADA>40, lymphocytic effusion)
    1. Start treatment empirically
  9. No cause identified
    1. Spiral CT for Pulmonary Embolism
    2. Consider Bronchoscopy
    3. Consider Thoracoscopy with biopsy
  • Management
  • Chronic or malignant Pleural Effusion
  1. Thoracentesis
    1. Used for first occurrence and infrequent recurrence
  2. Indwelling pleural catheter (e.g. PleurX Catheter)
    1. Malignant Pleural Effusion with fluid reaccumulation
  3. Other procedures for frequent recurrence
    1. Pleurodesis
    2. Pleurectomy
    3. Decortication
  4. For Frequent Recurrence
    1. Open windows
    2. Supplemental Oxygen
    3. Semi-Fowler's position
    4. Bronchodilators
    5. Prednisone
    6. Narcotic Analgesic
    7. Anxiolytics
    8. Diuretics
    9. Palliative Radiotherapy
  • References
  1. Natesan (2020) Crit Dec Emerg Med 34(7): 29-41
  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. Porcel (2013) Dis Mon 59(2): 29-57 [PubMed]
  6. Rabman (2005) Br Med Bull 72:31-47 [PubMed]
  7. Saguil (2014) Am Fam Physician 90(2): 99-104 [PubMed]
  8. Shen-Wagner (2023) Am Fam Physician 108(5): 464-75 [PubMed]
  9. Weldon (2012) Emerg Med Clin N Am 30(2): 475-9 [PubMed]