Pleural Effusion-Malignant

Epidemiology

  • Pleural Metastases are the Second Most Common Cause of Pleural Effusion
  • Incidence: 200,000 per year (in USA)

Etiology of Pleural Metastases


Physiology

Mechanisms Contributing to Pleural Effusion Formation in Malignancy-Associated Pleural Effusions

  • Acute Pulmonary Embolism (PE) (see Acute Pulmonary Embolism, [[Acute Pulmonary Embolism]]): if present
  • Bronchial Obstruction with Decreased Pleural Pressure: if present
  • Hypoproteinemia: if present
  • Mediastinal Adenopathy with Decreased Pleural Lymphatic Drainage: if present
  • Pericardial Involvement: if present
  • Pleural Metastases with Increased Pleural Permeability: not the predominant mechanism in malignant effusion (since amount of protein entering pleural space is similar to that seen in CHF)
  • Pleural Metastases with Lymphatic Obstruction: predominant mechanism in malignant pleural effusion (since volume of lymph flow is decreased compared to TB, PE, and CHF effusions)
  • Post-Obstructive Pneumonia: if present
  • Radiation Pleuritis (see Radiation Pleuritis, [[Radiation Pleuritis]]): if present
  • Thoracic Duct Interruption (with Chylothorax) (see Pleural Effusion-Chylothorax, [[Pleural Effusion-Chylothorax]])

Diagnosis

Pleural Fluid (see Thoracentesis, [[Thoracentesis]])

  • Exudate
  • Appearance: may be bloody (but 50% have RBC counts <10,000/mm3)
  • pH: usually changes with glucose
  • LDH ratio: increased (most effusions that are exudates by LDH criteria but not by the protein criteria are malignant)
  • Total protein ratio: increased
  • Glucose: <60 mg/dL in 20% of cases (those with low glucose usually have low pH)
  • Cell count/ diff: eosinophilia is uncommon
  • Cytology: overall 40-87% sensitivity
    • Cytology is less frequently positive in cases due to squamous cell lung cancer (since main mechanisms of effusion formation are bronchial and lymphatic obstruction)
    • Cytology is less frequently positive in cases due to complicating PE, CHF, etc.
    • 75% sensitivity in cases due to NHL but only 25% sensitivity in cases due to Hodgkin’s
    • Cytology is more frequently positive in adenocarcinomas than in sarcomas
  • Cholesterol: elevated >55-60 mg/dL (seen in all exudates)
  • Pleural: serum cholesterol ratio: elevated (seen in all exudates)
  • Pleural fluid amylase: elevated in 10% of cases (source of malignancy is usually not the pancreas in these cases/ amylase in malignancy is usually of salivary type)
  • Tumor Markers: 30-40% of mailgnant effusions have CEA that is >10 ng/mL (while benign effusions rarely exceed this level)
    • However, most malignant effusions have positive cytology (making CEA measurement unnecessary)

Pleural Biopsy (see xxxxx, [[xxxx]])

  • Sensitivity: 40-75%
    • Cytology may be more sensitive than pleural biopsy for malignant effusions (but this is controversial)

Clinical Manifestations

Pulmonary Manifestations

Other Manifestations

  • xxx

Treatment

Pleurodesis (see Pleurodesis, [[Pleurodesis]])

Indications for Pleurodesis

  • xxx

Timing of Pleurodesis

  • No need to wait until drainage falls off before pleurodesis

Chest Tube Size

  • Clinical Efficacy
    • UK-Based TIME1 Trial Comparing Small-Bore Chest Tube vs Large-Bore Chest for Pleurodesis in Malignant Pleural Effusion (JAMA, 2015) [MEDLINE]: 2×2 factorial phase 3 randomized trial
      • NSAID’s and Opiates Demonstrated No Difference in Pain Scores: however, NSAID’s demonstrated a higher need for rescue medication
      • NSAID’s Did Not Impact the Efficacy of Pleurodesis at 3 mo
      • Placement of 12F Chest Tube vs 24F Chest Tube was Associated with a Modest Reduction in Pain
      • Placement of a 24 Chest Tube was Superior to a 12F Chest Tube in Terms of Pleurodesis Efficacy

Technique

  • Pre-Pleurodesis Anesthesia: lidocaine 4 mg/kg (?) in 50 mL NS injected into pleural space, then x min of waiting with repositioning

  • Pleurodesis Agents
    (chemical agent followed by 50 mL NS flush, clamp x 2 hrs, then suction)

  • Doxycycline: 500 mg in 50 ml saline, flush with 50 ml saline

    • May be preferred agent for treatment of PTX
  • Talc Slurry: 6-10 g instillation
    • Risk of ARDS may be related to particle size <30 um (check talc)
  • Bleomycin:
  • Thoracoscopic Talc Insufflation:
    • Risk of ARDS may be related to particle size <30 um (check talc)
  • Pleural Abrasion
  • Silver Nitrate

Video-Assisted Thoracoscopic (VATS) Pleurodesis

Indications

  • xxx

Contraindcations

  • xxx

Complications

  • xxx

Pleurx Catheter

Indications

  • Malignant Pleural Effusion without Trapped Lung
  • Malignant Pleural Effusion with Trapped Lung
    • Placement in Patients with Trapped Lung is Associated with Moderate Improvement in Quality of Life Indices [MEDLINE]

Contraindications

  • xxx

Complications

  • xxx

References

  • Malignant pleural effusion in the presence of trapped lung. Five-year experience of PleurX tunnelled catheters. Interact Cardiovasc Thorac Surg. 2009 Dec;9(6):961-4. doi: 10.1510/icvts.2009.211516. Epub 2009 Jul 28 [MEDLINE]
  • Effect of Opioids vs NSAIDs and Larger vs Smaller Chest Tube Size on Pain Control and Pleurodesis Efficacy Among Patients With Malignant Pleural Effusion: The TIME1 Randomized Clinical Trial. JAMA. 2015 Dec;314(24):2641-53 [MEDLINE]