Pleural Effusion

1. Overview

Pleural effusion is the abnormal accumulation of fluid in the pleural space, the potential space between the visceral and parietal pleura surrounding the lungs. The pleural space normally contains 5-15 mL of fluid that acts as a lubricant during respiratory movements. [1] When fluid accumulation exceeds absorption capacity, a pleural effusion develops, which can compress lung tissue and impair respiratory function.

Pleural effusions are a common clinical problem, affecting approximately 1.5 million people annually in the United States alone. [2] The condition represents a manifestation of underlying disease rather than a primary diagnosis, with over 50 different causes identified. Early and accurate diagnosis is crucial as the underlying aetiology may range from benign conditions such as heart failure to life-threatening malignancies or infections requiring urgent intervention. [3]

The key to clinical management lies in distinguishing between transudative and exudative effusions using Light's criteria, which guides differential diagnosis and subsequent investigation. Understanding the pathophysiology of pleural fluid formation and absorption, coupled with systematic clinical assessment and targeted investigations, enables appropriate treatment directed at the underlying cause. [4]

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2. Epidemiology

Prevalence and Incidence

Pleural effusion is one of the most common pleural disorders encountered in clinical practice. In the United Kingdom, an estimated 3,000 new cases per million population occur annually. [5] The condition affects all age groups but is more prevalent in older adults, with incidence increasing significantly after 65 years of age. [6]

Aetiology Distribution

The underlying causes vary depending on geographical location, healthcare setting, and population demographics:

Most Common Causes Overall: [11]

• Heart failure: 35-40%
• Pneumonia/parapneumonic: 20-25%
• Malignancy: 15-20%
• Pulmonary embolism: 5-10%
• Cirrhosis: 5%
• Other: 10-15%

Transudative vs Exudative Distribution: Approximately 60% of pleural effusions are transudates, with heart failure being the leading cause. [12] Exudative effusions account for 40%, with malignancy and infection being the most common aetiologies in this category. [13]

Demographics

Age: The median age at presentation is 65 years, with malignant effusions occurring at a mean age of 72 years. [14] Parapneumonic effusions have a bimodal distribution affecting younger adults with community-acquired pneumonia and elderly patients with aspiration pneumonia.

Sex: No significant sex predilection exists for pleural effusions overall, though specific causes show variation. Malignant mesothelioma affects men 4-5 times more frequently than women due to occupational asbestos exposure. [15]

Geographical Variation: Tuberculous pleural effusions are the leading cause in low- and middle-income countries, particularly in sub-Saharan Africa and South Asia where TB prevalence is high. [16] In developed countries, heart failure and malignancy predominate.

Risk Factors

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3. Aetiology and Pathophysiology

Pleural Fluid Dynamics

Under normal physiological conditions, pleural fluid formation and absorption are tightly regulated. Fluid enters the pleural space from the parietal pleural capillaries at approximately 0.01 mL/kg/hour and is absorbed primarily through parietal pleural lymphatics at a rate of up to 0.3 mL/kg/hour. [17] This creates a net outward flux, maintaining the small volume of pleural fluid necessary for lubrication.

Starling Forces Governing Pleural Fluid Formation:

The movement of fluid across the pleural membrane follows Starling's law:

Net fluid movement = K[(Pcap - Ppl) - σ(πcap - πpl)]

Where:

• K = filtration coefficient
• Pcap = capillary hydrostatic pressure
• Ppl = pleural space hydrostatic pressure
• σ = reflection coefficient for protein
• πcap = capillary oncotic pressure
• πpl = pleural fluid oncotic pressure

Parietal Pleura (Systemic Circulation):

• Capillary hydrostatic pressure: 30 cmH₂O
• Pleural space pressure: -5 cmH₂O
• Net hydrostatic gradient favouring filtration: 35 cmH₂O

Visceral Pleura (Pulmonary Circulation):

• Capillary hydrostatic pressure: 11 cmH₂O
• Lower filtration pressure than parietal pleura
• Primarily involved in protein clearance

The parietal pleural lymphatics have enormous absorptive capacity (up to 20 times normal production rate), which explains why pleural effusions do not develop until this compensatory mechanism is overwhelmed. [18]

Mechanisms of Effusion Formation

Transudative Effusions develop when Starling forces are altered without inflammation or increased vascular permeability:

1. Increased hydrostatic pressure: Heart failure, fluid overload
2. Decreased oncotic pressure: Hypoalbuminaemia (nephrotic syndrome, cirrhosis, malnutrition)
3. Decreased pleural space pressure: Atelectasis
4. Movement from peritoneal cavity: Hepatic hydrothorax, peritoneal dialysis

The pleural membrane remains intact, and fluid has low protein content (less than 30 g/L) with few cells.

Exudative Effusions result from increased vascular permeability, impaired lymphatic drainage, or direct pleural involvement:

1. Increased capillary permeability: Inflammation (pneumonia, pancreatitis), malignancy
2. Impaired lymphatic drainage: Malignant lymphatic obstruction, tuberculosis
3. Pleural inflammation: Autoimmune disease, post-cardiac injury syndrome
4. Disrupted pleural integrity: Oesophageal rupture, chylothorax

The damaged pleural membrane allows protein and cells to enter the pleural space, resulting in high protein content (> 30 g/L) and elevated lactate dehydrogenase (LDH). [19]

Molecular Pathophysiology of Exudative Inflammation:

Inflammatory mediators including interleukin-8 (IL-8), tumour necrosis factor-alpha (TNF-α), and vascular endothelial growth factor (VEGF) increase vascular permeability and recruit inflammatory cells. [20] In malignant effusions, VEGF production by tumour cells is a key driver of fluid accumulation. Pleural mesothelial cells also contribute to inflammation through cytokine production and expression of adhesion molecules.

Parapneumonic Effusion Evolution:

Parapneumonic effusions progress through three stages:

1. Exudative stage (Days 1-2): Sterile inflammatory response, thin fluid
2. Fibrinopurulent stage (Days 3-7): Bacterial invasion, neutrophil influx, fibrin deposition, pH drop
3. Organizing stage (Days 7-14+): Fibroblast proliferation, pleural peel formation, loculation

The transition from simple to complicated parapneumonic effusion occurs when bacterial invasion causes glucose consumption, lactic acid production, and pH decline below 7.2, indicating need for drainage. [21]

Classification by Aetiology

Transudative Causes:

• Cardiac: Heart failure (most common), constrictive pericarditis, superior vena cava obstruction
• Hepatic: Cirrhosis with ascites (hepatic hydrothorax)
• Renal: Nephrotic syndrome, glomerulonephritis, peritoneal dialysis
• Other: Hypoalbuminaemia, hypothyroidism, pulmonary embolism (can be transudate or exudate)

Exudative Causes:

• Infectious: Parapneumonic effusion, empyema, tuberculosis, fungal, parasitic
• Malignant: Lung cancer, breast cancer, lymphoma, mesothelioma, metastatic disease
• Thromboembolic: Pulmonary embolism (exudative in 70%)
• Autoimmune: Rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome
• Gastrointestinal: Oesophageal rupture, pancreatitis, subphrenic abscess
• Drug-induced: Amiodarone, methotrexate, nitrofurantoin
• Post-cardiac injury: Dressler's syndrome, post-CABG
• Other: Asbestos exposure, radiation, uraemia (can be exudative), chylothorax, haemothorax

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4. Clinical Presentation

Symptoms

The clinical presentation varies depending on effusion size, rate of accumulation, and underlying aetiology. Small effusions (less than 300 mL) may be asymptomatic and discovered incidentally on imaging.

Cardinal Symptoms:

Associated Symptoms (Clues to Aetiology):

• Fever, rigors, purulent sputum: Parapneumonic effusion/empyema
• Weight loss, night sweats, haemoptysis: Malignancy or tuberculosis
• Peripheral oedema, orthopnoea, paroxysmal nocturnal dyspnoea: Heart failure
• Ascites, jaundice, confusion: Hepatic hydrothorax
• Leg swelling, sudden dyspnoea: Pulmonary embolism
• Joint pains, rash: Connective tissue disease

Red Flag Symptoms Requiring Urgent Assessment:

• Severe dyspnoea at rest (respiratory distress)
• Haemoptysis (malignancy, TB, PE)
• Chest pain with haemodynamic instability (haemothorax, PE)
• Fever with signs of sepsis (empyema)

Signs

General Inspection:

• Respiratory distress (tachypnoea, accessory muscle use)
• Cachexia (malignancy, TB)
• Peripheral oedema (heart failure, nephrotic syndrome)
• Jaundice, spider naevi, palmar erythema (chronic liver disease)
• Clubbing (malignancy, empyema)
• Reduced performance status

Respiratory Examination:

Classic Triad of Pleural Effusion:

1. Stony dull percussion
2. Reduced breath sounds
3. Reduced tactile vocal fremitus

Advanced Examination Techniques:

Egophony (E-to-A changes): Present at the upper border of large effusions where compressed lung creates bronchial breathing. The spoken "E" sound is heard as "A" through the stethoscope.

Tracheal Deviation: Large effusions (> 1500 mL) may cause mediastinal shift away from the effusion. However, massive pleural effusion with lung collapse may cause ipsilateral deviation due to volume loss. Contralateral deviation suggests tension hydrothorax requiring urgent drainage.

Shifting Dullness: Unlike ascites, pleural effusion dullness typically does not shift with position change in the timeframe of clinical examination, although fluid does redistribute over hours.

Lymphadenopathy: Examine for supraclavicular, axillary, and inguinal nodes (malignancy, TB, lymphoma).

Signs Suggesting Specific Aetiologies:

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5. Differential Diagnosis

Approach to Differential Diagnosis

The differential diagnosis is guided primarily by whether the effusion is a transudate or exudate, determined by Light's criteria following pleural fluid analysis. [23]

Transudative Effusions

1. Congestive Heart Failure (Most Common Transudate)

• Key Features: Bilateral effusions (70%), peripheral oedema, elevated JVP, S3 gallop
• Distinguishing Features: BNP > 1500 pg/mL, improvement with diuresis
• Frequency: Accounts for 35-40% of all pleural effusions

2. Hepatic Hydrothorax

• Key Features: Right-sided effusion (70%), ascites, portal hypertension signs
• Distinguishing Features: Protein gradient > 1.1 g/dL between serum and pleural fluid
• Mechanism: Fluid moves from peritoneum through diaphragmatic defects
• Frequency: 5-10% of patients with cirrhosis and ascites [24]

3. Nephrotic Syndrome

• Key Features: Bilateral effusions, anasarca, proteinuria > 3.5 g/day, hypoalbuminaemia
• Distinguishing Features: Serum albumin less than 25 g/L, urinary protein:creatinine ratio > 350 mg/mmol
• Frequency: Present in 20% of nephrotic syndrome patients

4. Peritoneal Dialysis

• Key Features: History of peritoneal dialysis, usually right-sided
• Distinguishing Features: High glucose in pleural fluid if recent dialysis
• Mechanism: Pleuroperitoneal communication

5. Hypothyroidism

• Key Features: Bradycardia, hypothyroid features, elevated TSH
• Distinguishing Features: Often bilateral, resolves with thyroid replacement
• Frequency: Rare cause (less than 1%)

6. Pulmonary Embolism (Can Be Transudate or Exudate)

• Key Features: Sudden onset dyspnoea, pleuritic pain, usually small effusion
• Distinguishing Features: 75% are exudative; 25% transudative on initial tap [25]
• Investigation: CTPA required for diagnosis

Exudative Effusions

1. Parapneumonic Effusion and Empyema

• Key Features: Fever, productive cough, consolidation on imaging
• Distinguishing Features: Low pH (less than 7.2), low glucose (less than 3.4 mmol/L), elevated LDH, positive Gram stain/culture
• Classification:
  • "Uncomplicated: pH > 7.2, glucose > 3.4, clear fluid, negative culture"
  • "Complicated: pH less than 7.2 or glucose less than 3.4, culture may be positive, requires drainage"
  • "Empyema: Frank pus, positive Gram stain, requires chest tube drainage"
• Frequency: 20-25% of all effusions, 40% of pneumonia cases [26]

2. Malignant Pleural Effusion

• Key Features: Progressive dyspnoea, weight loss, may be asymptomatic
• Common Primary Tumours: Lung (35%), breast (25%), lymphoma (10%), ovarian, gastric, unknown primary (10%)
• Distinguishing Features: Positive cytology (60% sensitivity), elevated pleural fluid LDH, bloody effusion, rapid re-accumulation after drainage
• Prognosis: Median survival 4-9 months depending on primary tumour [27]
• Frequency: 15-20% of all effusions

3. Tuberculous Pleural Effusion

• Key Features: Subacute onset, fever, night sweats, weight loss, predominantly young adults in endemic areas
• Distinguishing Features: Lymphocytic predominance (> 50%), elevated adenosine deaminase (ADA > 40 U/L has 90% sensitivity and specificity), positive TB culture (12-70%), pleural biopsy showing granulomas (80% sensitivity) [28]
• Frequency: Most common cause in TB-endemic regions; less than 5% in developed countries

4. Pulmonary Embolism (Exudative)

• Key Features: Sudden dyspnoea, pleuritic pain, tachycardia, risk factors for VTE
• Distinguishing Features: Usually small (less than 500 mL), often bloody, D-dimer elevated, CTPA diagnostic
• Frequency: 5-10% of all effusions

5. Connective Tissue Disease

Rheumatoid Arthritis:

• Features: More common in men, may precede joint symptoms
• Distinguishing Features: Low glucose (less than 1.6 mmol/L), low pH (less than 7.0), elevated RF in pleural fluid, cholesterol crystals
• Frequency: 5% of RA patients

Systemic Lupus Erythematosus:

• Features: Associated with lupus serositis
• Distinguishing Features: Positive ANA in pleural fluid, LE cells, low complement
• Frequency: 30-50% of SLE patients at some point [29]

6. Post-Cardiac Injury Syndrome (Dressler's Syndrome)

• Key Features: 2-10 weeks post-MI or cardiac surgery, pleuritic pain, fever, pericardial friction rub
• Distinguishing Features: Elevated ESR/CRP, often with pericardial effusion
• Frequency: less than 5% post-MI with modern reperfusion therapy

7. Pancreatitis

• Key Features: Epigastric pain, elevated serum amylase, usually left-sided
• Distinguishing Features: Elevated pleural fluid amylase (> 1000 U/L or pleural:serum ratio > 1.0)
• Frequency: 10-20% of acute pancreatitis cases

8. Oesophageal Rupture

• Key Features: Severe chest pain, subcutaneous emphysema, recent vomiting/instrumentation
• Distinguishing Features: Low pleural fluid pH (less than 6.0), elevated salivary amylase, food particles, pleural fluid squamous cells
• Emergency: Requires urgent surgical intervention

9. Chylothorax

• Key Features: Milky appearance, history of trauma or surgery
• Distinguishing Features: Triglycerides > 1.24 mmol/L (diagnostic), presence of chylomicrons, lymphocyte-predominant
• Causes: Trauma, malignancy (lymphoma), lymphatic abnormalities

10. Mesothelioma

• Key Features: Asbestos exposure 20-40 years prior, chest pain, dyspnoea
• Distinguishing Features: Pleural thickening/nodularity on CT, requires pleural biopsy for diagnosis
• Prognosis: Median survival 9-12 months

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6. Investigations

Initial Assessment

Chest Radiograph (Posteroanterior and Lateral Views):

• Minimum detectable volume: 200 mL (blunting of costophrenic angle on PA view); 75 mL on lateral view
• Classic findings: Meniscus sign (concave upper border), obscured hemidiaphragm, blunted costophrenic angle
• Large effusion: Homogeneous opacification, mediastinal shift away from effusion
• Loculated effusion: Lenticular opacity that does not layer on lateral decubitus film
• Sensitivity: 67% for effusions less than 500 mL; > 95% for effusions > 500 mL [30]

Lateral Decubitus Radiograph:

• Detects smaller effusions (50-100 mL)
• Differentiates free-flowing from loculated effusions
• If fluid layers > 10 mm, amenable to thoracentesis

Ultrasound:

• Gold standard for detection: Detects as little as 5-10 mL
• Mandatory for procedures: BTS guidelines recommend ultrasound guidance for all pleural procedures to reduce complications [31]
• Characterization: Simple (anechoic) vs complex (septations, debris, echogenic)
• Advantages: Bedside availability, no radiation, identifies loculations, safe needle entry site
• Sensitivity and specificity: Both > 90% for pleural fluid detection

CT Chest with Contrast:

• Indications: Identify underlying cause (malignancy, pneumonia), evaluate pleural thickening, assess loculations, differentiate empyema from lung abscess
• Findings suggesting malignancy: Nodular pleural thickening, mediastinal lymphadenopathy, pleural thickness > 1 cm, circumferential pleural involvement
• Findings suggesting empyema: Split pleura sign (enhancement of visceral and parietal pleura), loculations, adjacent consolidation

Diagnostic Thoracentesis

Indications:

• All new unexplained pleural effusions > 10 mm on lateral decubitus or ultrasound
• Exception: Typical presentation of heart failure with bilateral effusions responding to diuresis within 3 days

Technique:

• Patient position: Sitting upright, leaning forward over bedside table
• Ultrasound guidance: Mandatory (reduces pneumothorax risk from 9% to 3%) [32]
• Site: Intercostal space 1-2 levels below upper fluid level, mid-scapular or posterior axillary line
• Approach: Enter above rib to avoid neurovascular bundle
• Sample volume: 50-60 mL sufficient for all analyses
• Fluid appearance: Note colour (straw, bloody, purulent, milky), clarity, odour

Contraindications (Relative):

• INR > 1.5 (reverse if possible; not absolute contraindication if urgent)
• Platelet count less than 25 × 10⁹/L
• Mechanical ventilation with PEEP (increased pneumothorax risk)
• Skin infection at entry site

Light's Criteria for Transudate vs Exudate

Light's Criteria (Exudate if ANY ONE of the Following): [33]

Performance Characteristics:

• Sensitivity for exudates: 98%
• Specificity: 83% (17% of transudates misclassified as exudates)
• Common misclassification: Heart failure patients on diuretics may have exudative criteria due to concentration of pleural fluid protein

Modifications for Diuresed Heart Failure Patients:

• If Light's criteria suggest exudate but clinical suspicion for transudate (heart failure), calculate serum-pleural albumin gradient
• Gradient > 1.2 g/dL indicates transudate (corrects misclassification in 70-90% of cases) [34]

Why Light's Criteria Works:

Exudative processes increase capillary permeability, allowing protein and LDH to leak into pleural space. Additionally, pleural inflammation causes local LDH release from inflammatory cells and mesothelial cells. The ratios correct for serum values and are more accurate than absolute values.

Historical Context: Prior to Light's 1972 landmark study, pleural protein less than 3.0 g/dL defined transudate. This had poor sensitivity and specificity. Light's criteria revolutionized pleural fluid interpretation and remains the gold standard 50+ years later.

Pleural Fluid Analysis

Mandatory Tests on All Samples:

pH Measurement:

• Must be measured in blood gas analyser (not litmus paper)
• Sample must be heparinized, air-free, analyzed immediately (pH drops if delayed)
• pH less than 7.2 in parapneumonic effusion = complicated effusion requiring chest tube drainage [35]
• pH less than 7.0: Strongly suggests empyema, rheumatoid pleurisy, or oesophageal rupture

Glucose:

• less than 3.4 mmol/L (or pleural:serum ratio less than 0.5) indicates:
  • Complicated parapneumonic effusion/empyema (most common)
  • Rheumatoid pleurisy (often less than 1.6 mmol/L)
  • TB pleuritis
  • Malignancy (advanced)
  • Oesophageal rupture

Cell Count and Differential:

Additional Tests Based on Clinical Suspicion:

Cytology:

• Send 50-100 mL for optimal yield
• Sensitivity: 60% on first sample, 70% on second, 80% on third
• False negatives: Mesothelioma (requires biopsy), lymphoma
• Repeated sampling: If high clinical suspicion and initial negative, repeat thoracentesis

Further Investigations

Contrast-Enhanced CT Chest:

• Indications: All exudative effusions to identify underlying cause
• Yield: Identifies cause in 50-70% when CXR non-diagnostic
• Findings to assess: Lung parenchyma, pleural thickening/nodularity, lymphadenopathy, masses

Thoracic Ultrasound:

• Characterize complex vs simple effusion
• Identify septations and loculations
• Guide thoracentesis or chest tube placement
• Assess pleural thickening

Bronchoscopy:

• Indications: Suspected endobronchial lesion, haemoptysis, post-obstructive pneumonia, cytology-negative suspected lung cancer
• Yield: Low for pleural effusion investigation unless central airway lesion present

CT Pulmonary Angiography:

• Indication: Suspected pulmonary embolism
• Findings: Filling defect in pulmonary vessels, peripheral wedge-shaped consolidation

Thoracoscopy (Medical or VATS):

• Indications: Exudative effusion with negative cytology and strong suspicion of malignancy; TB suspected with negative pleural fluid analysis
• Diagnostic yield: 95% for malignancy, 80% for TB (granulomas on pleural biopsy)
• Advantages: Visual inspection of pleural cavity, directed biopsies, pleurodesis at same time
• Contraindications: Uncorrectable coagulopathy, hypoxia (unable to tolerate single lung ventilation), extensive adhesions

Image-Guided Pleural Biopsy:

• CT-guided cutting needle biopsy: For focal pleural thickening/masses
• Yield: 80-90% for malignancy
• Complications: Pneumothorax (15%), bleeding (less than 5%)

Serum Tests:

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7. Management

General Principles

Management of pleural effusion is directed at:

1. Treating the underlying cause
2. Relieving symptoms through drainage when appropriate
3. Preventing recurrence in cases such as malignant effusion
4. Preventing complications such as empyema formation

The decision to drain a pleural effusion depends on symptoms, underlying diagnosis, and risk of complications. Not all effusions require drainage.

Algorithm

PLEURAL EFFUSION CONFIRMED ON IMAGING
                ↓
┌──────────────────────────────────────────┐
│    Symptomatic? Large (> 500 mL)?         │
│    Underlying diagnosis unknown?          │
└──────────────────────────────────────────┘
                ↓
        DIAGNOSTIC THORACENTESIS
    (Ultrasound-guided, send for full analysis)
                ↓
┌──────────────────────────────────────────┐
│   LIGHT'S CRITERIA                       │
│   Transudate or Exudate?                 │
└──────────────────────────────────────────┘
       ↓                         ↓
   TRANSUDATE                 EXUDATE
       ↓                         ↓
Treat underlying cause    Investigate cause
- Heart failure           - CT chest
- Diuresis                - Targeted tests
- Cirrhosis management    - Consider thoracoscopy
- Renal support                  ↓
                        PARAPNEUMONIC?
                        Check pH and glucose
                        ↓
              pH less than 7.2 or glucose less than 3.4?
                        ↓ YES
                  CHEST TUBE DRAINAGE
                  + Antibiotics
                        ↓ NO
              Antibiotics alone, monitor
                        ↓
                    MALIGNANT?
                Positive cytology/biopsy?
                        ↓ YES
           Large/symptomatic/recurrent?
                        ↓
        THERAPEUTIC DRAINAGE ± PLEURODESIS
           or Indwelling pleural catheter

Conservative Management

Indications for Conservative Approach (No Drainage):

• Small, asymptomatic effusions (less than 500 mL)
• Transudative effusions responding to medical management
• Uncomplicated parapneumonic effusion (pH > 7.2, glucose > 3.4) treated with antibiotics alone

Medical Management by Underlying Cause:

Heart Failure:

• Diuretics: Furosemide 40-80 mg PO/IV daily (titrate to response)
• ACE inhibitor or ARB for systemic afterload reduction
• Beta-blocker if reduced ejection fraction
• Monitor fluid balance, daily weights
• Effusions typically resolve within 1-2 weeks of adequate diuresis [37]

Hepatic Hydrothorax:

• Sodium restriction (less than 2 g/day)
• Diuretics: Spironolactone 100-200 mg + furosemide 40-80 mg daily
• Large volume paracentesis if tense ascites
• TIPS if refractory (reduces recurrence but high morbidity)
• Liver transplantation for eligible patients

Nephrotic Syndrome:

• Treat underlying kidney disease
• Immunosuppression as per cause (steroids for minimal change, etc.)
• Diuretics with caution (risk of intravascular depletion)

Therapeutic Thoracentesis

Indications:

• Symptomatic effusion causing dyspnoea
• Diagnostic sampling if etiology unknown
• Malignant effusion for symptom relief

Volume Limits:

• Recommended maximum: 1500 mL per procedure to reduce risk of re-expansion pulmonary oedema (RPE) [38]
• Stop drainage if: Chest discomfort, persistent cough develops (suggests RPE or pneumothorax)
• Repeated drainage: Can be performed as needed for symptom relief

Complications:

Chest Tube Drainage

Indications for Chest Tube (Intercostal Drain):

1. Empyema (frank pus on thoracentesis)
2. Complicated parapneumonic effusion (pH less than 7.2, glucose less than 3.4 mmol/L, LDH > 1000 U/L, positive Gram stain)
3. Haemothorax (traumatic or spontaneous)
4. Chylothorax (conservative management failure)
5. Large recurrent malignant effusion as bridge to pleurodesis or indwelling catheter

Technique:

• Ultrasound guidance: Mandatory to identify safe insertion site
• Size: Small-bore drains (10-14 Fr) equally effective as large-bore for non-traumatic effusions, better tolerated [39]
• Position: Patient sitting or semi-recumbent, insertion in "safe triangle" (anterior to latissimus dorsi, lateral to pectoralis major, below axilla, above 5th intercostal space)
• Seldinger technique: Preferred for small-bore drains

Management of Chest Tube:

• Suction: Low-grade suction (-10 to -20 cmH₂O) if lung not expanding
• Flushing: Not recommended routinely; risk of infection
• Clamping: Never clamp functioning drain (risk of tension)
• Monitoring: Daily CXR, fluid output, clinical improvement

Removal Criteria:

• Drainage less than 200 mL per 24 hours for empyema/parapneumonic
• Drainage less than 150 mL per 24 hours for malignant effusion
• Lung re-expanded on imaging
• Cessation of air leak (if pneumothorax present)

Intrapleural Fibrinolytics

Indications:

• Complicated parapneumonic effusion/empyema with loculations or failure of simple drainage
• Retained haemothorax (controversial)

Evidence:

• MIST-2 trial: Combination intrapleural tissue plasminogen activator (tPA) and DNase reduced need for surgery and length of hospital stay compared to placebo in empyema/complicated parapneumonic effusion [40]
• Regimen: tPA 10 mg + DNase 5 mg in 30 mL normal saline twice daily for 3 days via chest tube (clamp for 1 hour, then drain)

Contraindications:

• Active bleeding
• Recent surgery or trauma
• Bronchopleural fistula (relative)

Surgical Management

Video-Assisted Thoracoscopic Surgery (VATS):

Indications:

• Failed medical management of empyema (persistent sepsis, loculations despite fibrinolytics)
• Diagnosis: exudative effusion with negative cytology and high suspicion for malignancy
• Pleural biopsy for TB or other chronic inflammation

Procedure:

• Evacuation of empyema, breakdown of loculations
• Decortication if pleural peel present
• Pleurodesis for malignant effusion
• Conversion to thoracotomy: If extensive adhesions or inability to complete procedure

Open Thoracotomy and Decortication:

• Indication: Chronic empyema with thick pleural peel (> 6 weeks), failed VATS
• Outcome: Successful in > 90% of cases but significant morbidity

Management by Specific Aetiology

Parapneumonic Effusion and Empyema:

Antibiotics:

• Choice: Broad-spectrum covering Streptococcus pneumoniae, Staphylococcus aureus, anaerobes
• Empiric regimen: Co-amoxiclav 1.2 g IV TDS OR ceftriaxone 2 g IV OD + metronidazole 500 mg IV TDS
• Adjust: Based on culture and sensitivities
• Duration: Minimum 3-4 weeks total (IV 1-2 weeks, then oral)

Drainage Strategy:

• Uncomplicated: Antibiotics alone, no drainage
• Complicated (pH less than 7.2, glucose less than 3.4): Chest tube + antibiotics ± fibrinolytics
• Empyema: Chest tube + antibiotics; VATS if failure at 5-7 days

Malignant Pleural Effusion:

Therapeutic Options:

Pleurodesis Technique:

• Complete drainage via chest tube
• Instil sclerosant (talc 4-5 g, doxycycline 500 mg, or bleomycin 60 units)
• Talc is most effective: 80-90% success rate [42]
• Clamp drain for 1 hour (rotation no longer recommended)
• Resume drainage; remove when less than 150 mL/24 hours
• Contraindications: Trapped lung (lung unable to re-expand), short life expectancy (less than 3 months)

Indwelling Pleural Catheter (IPC):

• Tunneled catheter inserted under local anesthesia
• Patient or caregiver drains 3-4 times per week at home
• Spontaneous pleurodesis: Occurs in 45-70% by 6-8 weeks, allowing catheter removal
• Complications: Infection (5%), catheter fracture, tumor tract seeding (rare)

Tuberculous Pleural Effusion:

• Standard anti-TB therapy: 2 months RIPE (rifampicin, isoniazid, pyrazinamide, ethambutol) + 4 months RI
• Drainage: Therapeutic thoracentesis for symptom relief; chest tube rarely needed
• Corticosteroids: Conflicting evidence; may reduce need for thoracentesis but no mortality benefit [43]
• Resolution: Effusion resolves over 4-8 weeks with treatment

Hepatic Hydrothorax:

• Medical management (diuretics, salt restriction) first-line
• Refractory cases: TIPS or liver transplantation
• Avoid chest tube: High risk of complications (infection, electrolyte depletion, renal failure)
• Therapeutic thoracentesis: For severe symptoms only; limit volume to 1000 mL

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8. Complications

Complications of Pleural Effusion (Untreated)

Complications of Procedures

Thoracentesis Complications:

• Pneumothorax: 3-6% (ultrasound guidance reduces risk by 50%)
• Hemothorax: less than 1% (avoid intercostal vessels)
• Re-expansion pulmonary edema: 0.5-1% (limit drainage to less than 1500 mL)
• Infection: less than 1%
• Splenic/liver laceration: Rare (ultrasound guidance prevents)

Chest Tube Complications:

• Malposition: 5-10% (imaging guidance reduces)
• Infection/empyema: 2-5%
• Hemorrhage: 1-2%
• Persistent air leak: 5% (bronchopleural fistula)
• Subcutaneous emphysema: 2-3%

Pleurodesis Complications:

• Pain: 80-90% (requires adequate analgesia)
• Fever: 20-30% (benign inflammatory response)
• Failure (recurrence): 10-30%
• Respiratory failure: Rare (avoid bilateral simultaneous pleurodesis)

VATS Complications:

• Prolonged air leak: 10-15%
• Bleeding: 2-5%
• Empyema: 2-3%
• Conversion to thoracotomy: 5-10%

Long-term Complications

• Pleural thickening: 30-50% of empyema cases; may cause restrictive physiology
• Chronic pain: 10-20% post-pleurodesis or chest tube
• Recurrence: Variable depending on underlying cause (malignancy 50% without pleurodesis, heart failure 30% with suboptimal treatment)

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9. Prognosis

Overall Prognosis

Prognosis depends entirely on the underlying cause rather than the effusion itself.

Prognostic Factors

Parapneumonic Effusion/Empyema:

• Poor prognostic factors: Age > 70, hospital-acquired infection, malignancy, immunosuppression, chronic kidney disease, delayed drainage
• RAPID score: Predicts mortality based on Renal function, Age, Purulence, Infection source, Dietary (albumin)

Malignant Effusion:

• Tumor type: Ovarian and lymphoma have better prognosis than lung and gastric
• Pleural fluid pH less than 7.28: Associated with shorter survival and lower pleurodesis success

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10. Prevention and Screening

Primary Prevention

• Pneumococcal and influenza vaccination: Reduces pneumonia incidence and thus parapneumonic effusions
• Early treatment of pneumonia: Appropriate antibiotics reduce progression to complicated effusion
• Heart failure optimization: ACEI/ARB, beta-blockers, diuretics reduce recurrent effusions
• Tuberculosis screening and treatment: In endemic areas and high-risk populations
• Smoking cessation: Reduces lung cancer risk

Secondary Prevention

• Adequate drainage of complicated parapneumonic effusion: Prevents fibrothorax and chronic empyema
• Pleurodesis for recurrent malignant effusion: Prevents repeated hospitalizations and improves quality of life
• Monitoring of high-risk conditions: Regular imaging in patients with advanced malignancy or cirrhosis

Screening

No population-based screening for pleural effusion exists. Targeted surveillance is appropriate for:

• Advanced malignancy patients: Clinical assessment and imaging for new dyspnoea
• Post-cardiac surgery patients: Routine CXR to detect asymptomatic effusions

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11. Key Guidelines

British Thoracic Society (BTS) Pleural Disease Guideline (2010): [46]

• Ultrasound guidance for all pleural procedures
• Light's criteria for transudate vs exudate
• pH less than 7.2 in parapneumonic effusion requires drainage
• Small-bore chest tubes (≤14 Fr) adequate for most non-traumatic effusions

American Thoracic Society (ATS) Guidelines (2000): [47]

• Management of parapneumonic effusions and empyema
• Risk stratification for drainage decisions

European Respiratory Society (ERS) Task Force (2015):

• Malignant pleural effusion investigation and management
• Indwelling pleural catheter use

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12. Exam-Focused Content

Light's Criteria: High-Yield Exam Content

Question: "A 68-year-old man with known heart failure presents with worsening dyspnoea and a right-sided pleural effusion. He has been on high-dose furosemide. Pleural fluid shows: protein 32 g/L (serum 65 g/L), LDH 210 U/L (serum 300 U/L, ULN 250 U/L). Is this a transudate or exudate?"

Systematic Approach:

1. Calculate protein ratio: 32/65 = 0.49 (less than 0.5, suggests transudate)
2. Calculate LDH ratio: 210/300 = 0.70 (> 0.6, suggests exudate)
3. Compare pleural LDH to upper limit normal: 210 > 167 (2/3 × 250), suggests exudate

Conclusion: Exudate by Light's criteria (LDH ratio > 0.6 AND pleural LDH > 2/3 ULN)

But wait! Patient is on diuretics for heart failure. This is likely a "pseudo-exudate."

Next step: Calculate serum-pleural albumin gradient.

• If albumin gradient > 1.2 g/dL, confirms transudate despite exudative Light's criteria

This is a classic viva question testing nuanced understanding of Light's criteria limitations.

Thoracentesis Technique: Step-by-Step

Viva Question: "Talk me through how you would perform a pleural aspiration."

Model Answer: "I would perform diagnostic pleural aspiration as follows:

Preparation:

• Obtain informed consent, explaining risks of pneumothorax, bleeding, pain, and re-expansion pulmonary oedema
• Position patient sitting upright, leaning forward over bedside table with arms supported
• Review recent imaging and perform ultrasound to confirm effusion and identify safe entry site

Procedure:

• Use ultrasound to mark insertion site: usually 1-2 intercostal spaces below upper fluid level, in mid-scapular or posterior axillary line
• Prepare skin with chlorhexidine, apply sterile drapes
• Infiltrate local anaesthetic (lidocaine 1%) to skin, subcutaneous tissue, down to pleura
• Insert needle just above superior border of rib to avoid neurovascular bundle
• Advance needle while aspirating until pleural fluid obtained
• For diagnostic tap, obtain 50-60 mL in appropriate sample bottles
• For therapeutic tap, attach drainage system and remove up to 1500 mL, stopping if patient develops chest pain or persistent cough
• Remove needle, apply sterile dressing
• Send samples for: protein, LDH, pH, glucose, cell count and differential, Gram stain, culture, and cytology
• Chest radiograph post-procedure only if symptoms suggesting pneumothorax (not routine if asymptomatic)

Key safety points: Ultrasound guidance is mandatory per BTS guidelines to reduce pneumothorax risk from 9% to 3%."

Empyema Management: Exam Favorite

Viva Scenario: "A 55-year-old smoker is admitted with right lower lobe pneumonia. On day 5 of IV antibiotics, he remains febrile with persistent dyspnoea. CXR shows right-sided pleural effusion. What do you do?"

Model Answer:

"This patient has a parapneumonic effusion complicating pneumonia. My key concern is whether this is a complicated effusion requiring drainage.

Immediate management:

1. Perform diagnostic thoracentesis under ultrasound guidance
2. Send pleural fluid for: pH (critical), glucose, LDH, protein, Gram stain, culture, cell count
3. Continue antibiotics

Interpretation:

• If pH > 7.2 AND glucose > 3.4 mmol/L: uncomplicated parapneumonic effusion, continue antibiotics alone
• If pH less than 7.2 OR glucose less than 3.4 mmol/L OR positive Gram stain OR frank pus: complicated effusion/empyema, requires chest tube drainage

Drainage approach:

• Insert small-bore (12-14 Fr) chest tube under ultrasound guidance
• Consider intrapleural fibrinolytics (tPA + DNase) if loculated or inadequate drainage after 48 hours
• Continue IV antibiotics for minimum 2 weeks, then oral for total 4-6 weeks
• Monitor with daily CXR for lung expansion
• If no improvement at 5-7 days despite chest tube and fibrinolytics, refer for VATS

Rationale: Delayed or inadequate drainage of complicated parapneumonic effusion leads to fibrothorax, prolonged illness, and 20% mortality at 1 year. Early aggressive drainage improves outcomes."

Common Exam Questions

Q1: What are the causes of a bloody pleural effusion?

A: Mnemonic: "TEMPT"

• Trauma (haemothorax)
• Embolus (pulmonary embolism)
• Malignancy (most common cause)
• Pancreatitis
• Tuberculosis

Additional: Asbestos-related disease, aortic dissection

Q2: What is the diagnostic criterion for haemothorax?

A: Pleural fluid haematocrit ≥50% of peripheral blood haematocrit

Q3: When should you suspect chylothorax and how do you confirm it?

A: Suspect when pleural fluid has milky appearance. Confirm with pleural fluid triglycerides > 1.24 mmol/L (> 110 mg/dL) or identification of chylomicrons on lipoprotein analysis.

Q4: What findings on pleural fluid analysis are most suggestive of rheumatoid pleurisy?

A:

• Very low glucose (less than 1.6 mmol/L, often less than 0.5)
• Very low pH (less than 7.0)
• Elevated LDH
• Cholesterol crystals
• High RF titre in pleural fluid
• May have low complement

Viva Points

Opening Statement for Pleural Effusion:

"Pleural effusion is the abnormal accumulation of fluid in the pleural space beyond the normal 5-15 mL. The key to diagnosis is distinguishing between transudate and exudate using Light's criteria, which has 98% sensitivity for identifying exudates. The most common cause overall is heart failure, accounting for 35-40% of cases. Management is directed at the underlying cause, with drainage indicated for symptomatic effusions, empyema, or diagnostic purposes."

Key Facts to Mention:

Light's Criteria (must know by heart): Exudate if ANY of:

1. Pleural protein / serum protein > 0.5
2. Pleural LDH / serum LDH > 0.6
3. Pleural LDH > 2/3 upper limit of normal

Parapneumonic Drainage Criteria: pH less than 7.2 OR glucose less than 3.4 mmol/L = requires chest tube drainage

Common Causes:

• Transudate: Heart failure, cirrhosis, nephrotic syndrome
• Exudate: Infection (parapneumonic/empyema), malignancy, PE, TB, autoimmune

Malignant Effusion Management:

• Pleurodesis with talc if lung re-expands (70-90% success)
• Indwelling pleural catheter if trapped lung or poor performance status
• Median survival 4-9 months

Evidence Base:

• MIST-2 trial: tPA + DNase reduced surgery need in empyema
• BTS guidelines mandate ultrasound for all pleural procedures

Common Mistakes

❌ Common Exam Failures:

1. Misinterpreting Light's criteria: Remember it's exudate if ANY ONE criterion is met, not all three
2. Failing to recognize pseudo-exudate: Diuresed heart failure patients may meet exudative criteria; use albumin gradient
3. Not considering PE: 70% of PE-related effusions are exudative; must maintain high index of suspicion
4. Draining all effusions: Small asymptomatic transudates don't need drainage
5. Missing empyema drainage criteria: pH is critical—must be measured in blood gas analyzer, not litmus paper
6. Forgetting ultrasound guidance: BTS mandates ultrasound for ALL pleural procedures
7. Excessive volume removal: Limit thoracentesis to 1500 mL to prevent re-expansion pulmonary edema
8. Wrong tube size: Small-bore (10-14 Fr) tubes are adequate for non-traumatic effusions; large-bore unnecessary and more painful

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13. References

1. Light RW. Pleural effusions. Med Clin North Am. 2011;95(6):1055-1070. doi:10.1016/j.mcna.2011.08.005

2. Porcel JM, Light RW. Diagnostic approach to pleural effusion in adults. Am Fam Physician. 2006;73(7):1211-1220. PMID: 16623206

3. Hooper C, Lee YCG, Maskell N. Investigation of a unilateral pleural effusion in adults: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65(Suppl 2):ii4-ii17. doi:10.1136/thx.2010.136978

4. Jany B, Welte T. Pleural effusion in adults—etiology, diagnosis, and treatment. Dtsch Arztebl Int. 2019;116(21):377-386. doi:10.3238/arztebl.2019.0377

5. Maskell NA, Butland RJA. BTS guidelines for the investigation of a unilateral pleural effusion in adults. Thorax. 2003;58(Suppl 2):ii8-ii17. doi:10.1136/thorax.58.suppl_2.ii8

6. Ferreiro L, Valdés L, San José E. Pleural effusion in the elderly. Arch Bronconeumol. 2015;51(6):284-291. doi:10.1016/j.arbres.2014.06.021

7. Wiener-Kronish JP, Matthay MA, Callen PW, et al. Relationship of pleural effusions to pulmonary hemodynamics in patients with congestive heart failure. Am Rev Respir Dis. 1985;132(6):1253-1256. doi:10.1164/arrd.1985.132.6.1253

8. Mattison LE, Coppage L, Alderman DF, et al. Pleural effusions in the medical ICU: prevalence, causes, and clinical implications. Chest. 1997;111(4):1018-1023. doi:10.1378/chest.111.4.1018

9. Falguera M, Carratalà J, Bielsa S, et al. Predictive factors, microbiology and outcome of patients with parapneumonic effusion. Eur Respir J. 2011;38(5):1173-1179. doi:10.1183/09031936.00204110

10. Clive AO, Kahan BC, Hooper CE, et al. Predicting survival in malignant pleural effusion: development and validation of the LENT prognostic score. Thorax. 2014;69(12):1098-1104. doi:10.1136/thoraxjnl-2014-205285

11. Light RW. Clinical practice. Pleural effusion. N Engl J Med. 2002;346(25):1971-1977. doi:10.1056/NEJMcp010731

12. Porcel JM. Pearls and myths in pleural fluid analysis. Respirology. 2011;16(1):44-52. doi:10.1111/j.1440-1843.2010.01794.x

13. Bintcliffe OJ, Maskell NA. Spontaneous pneumothorax. BMJ. 2014;348:g2928. doi:10.1136/bmj.g2928

14. DeBiasi EM, Pisani MA, Murphy TE, et al. Mortality among patients with pleural effusion undergoing thoracentesis. Eur Respir J. 2015;46(2):495-502. doi:10.1183/09031936.00217114

15. Robinson BW, Lake RA. Advances in malignant mesothelioma. N Engl J Med. 2005;353(15):1591-1603. doi:10.1056/NEJMra050152

16. Vorster MJ, Allwood BW, Diacon AH, Koegelenberg CF. Tuberculous pleural effusions: advances and controversies. J Thorac Dis. 2015;7(6):981-991. doi:10.3978/j.issn.2072-1439.2015.02.18

17. Miserocchi G. Physiology and pathophysiology of pleural fluid turnover. Eur Respir J. 1997;10(1):219-225. doi:10.1183/09031936.97.10010219

18. Charniot JC, Coirault C, Chemla D, et al. Pleural effusion and congestive heart failure. Am J Med Sci. 2000;319(4):246-252. doi:10.1016/s0002-9629(15)40743-7

19. Light RW, Macgregor MI, Luchsinger PC, Ball WC Jr. Pleural effusions: the diagnostic separation of transudates and exudates. Ann Intern Med. 1972;77(4):507-513. doi:10.7326/0003-4819-77-4-507

20. Antony VB, Godbey SW, Kunkel SL, et al. Recruitment of inflammatory cells to the pleural space. Chemotactic cytokines, IL-8, and monocyte chemotactic peptide-1 in human pleural fluids. J Immunol. 1993;151(11):7216-7223. PMID: 8258720

21. Colice GL, Curtis A, Deslauriers J, et al. Medical and surgical treatment of parapneumonic effusions: an evidence-based guideline. Chest. 2000;118(4):1158-1171. doi:10.1378/chest.118.4.1158

22. Wong CL, Holroyd-Leduc J, Straus SE. Does this patient have a pleural effusion? JAMA. 2009;301(3):309-317. doi:10.1001/jama.2008.937

23. Heffner JE, Brown LK, Barbieri CA. Diagnostic value of tests that discriminate between exudative and transudative pleural effusions. Chest. 1997;111(4):970-980. doi:10.1378/chest.111.4.970

24. Badillo R, Rockey DC. Hepatic hydrothorax: clinical features, management, and outcomes in 77 patients and review of the literature. Medicine (Baltimore). 2014;93(3):135-142. doi:10.1097/MD.0000000000000025

25. Stein PD, Terrin ML, Hales CA, et al. Clinical, laboratory, roentgenographic, and electrocardiographic findings in patients with acute pulmonary embolism and no pre-existing cardiac or pulmonary disease. Chest. 1991;100(3):598-603. doi:10.1378/chest.100.3.598

26. Taryle DA, Potts DE, Sahn SA. The incidence and clinical correlates of parapneumonic effusions in pneumococcal pneumonia. Chest. 1978;74(2):170-173. doi:10.1378/chest.74.2.170

27. Roberts ME, Neville E, Berrisford RG, et al. Management of a malignant pleural effusion: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65(Suppl 2):ii32-ii40. doi:10.1136/thx.2010.136994

28. Ruan SY, Chuang YC, Wang JY, et al. Revisiting tuberculous pleurisy: pleural fluid characteristics and diagnostic yield of mycobacterial culture in an endemic area. Thorax. 2012;67(9):822-827. doi:10.1136/thoraxjnl-2011-201363

29. Pego-Reigosa JM, Medeiros DA, Isenberg DA. Respiratory manifestations of systemic lupus erythematosus: old and new concepts. Best Pract Res Clin Rheumatol. 2009;23(4):469-480. doi:10.1016/j.berh.2009.01.002

30. Blackmore CC, Black WC, Dallas RV, Crow HC. Pleural fluid volume estimation: a chest radiograph prediction rule. Acad Radiol. 1996;3(2):103-109. doi:10.1016/s1076-6332(96)80402-7

31. Havelock T, Teoh R, Laws D, Gleeson F. Pleural procedures and thoracic ultrasound: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65(Suppl 2):ii61-ii76. doi:10.1136/thx.2010.137026

32. Gordon CE, Feller-Kopman D, Balk EM, Smetana GW. Pneumothorax following thoracentesis: a systematic review and meta-analysis. Arch Intern Med. 2010;170(4):332-339. doi:10.1001/archinternmed.2009.548

33. Light RW. The Light criteria: the beginning and why they are useful 40 years later. Clin Chest Med. 2013;34(1):21-26. doi:10.1016/j.ccm.2012.11.006

34. Roth BJ, O'Meara TF, Cragun WH. The serum-effusion albumin gradient in the evaluation of pleural effusions. Chest. 1990;98(3):546-549. doi:10.1378/chest.98.3.546

35. Heffner JE, Brown LK, Barbieri C, DeLeo JM. Pleural fluid chemical analysis in parapneumonic effusions. A meta-analysis. Am J Respir Crit Care Med. 1995;151(6):1700-1708. doi:10.1164/ajrccm.151.6.7767510

36. Liang QL, Shi HZ, Wang K, et al. Diagnostic accuracy of adenosine deaminase in tuberculous pleurisy: a meta-analysis. Respir Med. 2008;102(5):744-754. doi:10.1016/j.rmed.2007.12.007

37. Tang WH, Mullens W. Cardiorenal syndrome in decompensated heart failure. Heart. 2010;96(4):255-260. doi:10.1136/hrt.2009.166256

38. Mahfood S, Hix WR, Aaron BL, et al. Reexpansion pulmonary edema. Ann Thorac Surg. 1988;45(3):340-345. doi:10.1016/s0003-4975(10)62480-0

39. Rahman NM, Maskell NA, Davies CW, et al. The relationship between chest tube size and clinical outcome in pleural infection. Chest. 2010;137(3):536-543. doi:10.1378/chest.09-1044

40. Rahman NM, Maskell NA, West A, et al. Intrapleural use of tissue plasminogen activator and DNase in pleural infection. N Engl J Med. 2011;365(6):518-526. doi:10.1056/NEJMoa1012740

41. Dresler CM, Olak J, Herndon JE 2nd, et al. Phase III intergroup study of talc poudrage vs talc slurry sclerosis for malignant pleural effusion. Chest. 2005;127(3):909-915. doi:10.1378/chest.127.3.909

42. Tan C, Sedrakyan A, Browne J, et al. The evidence on the effectiveness of management for malignant pleural effusion: a systematic review. Eur J Cardiothorac Surg. 2006;29(5):829-838. doi:10.1016/j.ejcts.2005.12.025

43. Engel ME, Matchaba PT, Volmink J. Corticosteroids for tuberculous pleurisy. Cochrane Database Syst Rev. 2007;(4):CD001876. doi:10.1002/14651858.CD001876.pub2

44. Farjah F, Symons RG, Krishnadasan B, et al. Management of pleural space infections: a population-based analysis. J Thorac Cardiovasc Surg. 2007;133(2):346-351. doi:10.1016/j.jtcvs.2006.09.038

45. Burrows CM, Mathews WC, Colt HG. Predicting survival in patients with recurrent symptomatic malignant pleural effusions: an assessment of the prognostic values of physiologic, morphologic, and quality of life measures of extent of disease. Chest. 2000;117(1):73-78. doi:10.1378/chest.117.1.73

46. Maskell NA, Gleeson FV, Davies RJ. Standard pleural biopsy versus CT-guided cutting-needle biopsy for diagnosis of malignant disease in pleural effusions: a randomised controlled trial. Lancet. 2003;361(9366):1326-1331. doi:10.1016/S0140-6736(03)13079-6

47. American Thoracic Society. Management of malignant pleural effusions. Am J Respir Crit Care Med. 2000;162(5):1987-2001. doi:10.1164/ajrccm.162.5.ats8-00

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Last Reviewed: 2026-01-05 | MedVellum Editorial Team