What is the procedure for performing povidone iodine (polyvinylpyrrolidone iodine) pleurodesis?

Povidone-Iodine Pleurodesis Procedure

Povidone-iodine pleurodesis is performed by instilling 20 mL of 10% povidone-iodine mixed with 80 mL of normal saline (plus 2 mg/kg lidocaine) through a small-bore chest tube after complete lung re-expansion, clamping for 1-2 hours, then maintaining suction until drainage is <150-200 mL/24 hours. 1, 2, 3

Patient Selection and Pre-Procedure Requirements

Complete lung re-expansion is absolutely essential before attempting pleurodesis—failure to confirm this will result in treatment failure. 1 The following must be verified:

• Symptomatic dyspnea that improves with therapeutic thoracentesis 1
• Complete lung re-expansion confirmed on chest radiograph after fluid drainage 1, 4
• No evidence of trapped lung or mainstem bronchial obstruction (absolute contraindications) 1
• Adequate life expectancy to benefit from the procedure 1

Relative contraindications include massive effusion with rapid re-accumulation, active pleural infection, and concurrent corticosteroid therapy 1

Equipment and Preparation

• Insert a small-bore intercostal catheter (10-14 F) under ultrasound guidance 1—this provides equivalent success rates to large-bore tubes with less patient discomfort
• Drain pleural fluid in controlled fashion, limiting removal to 1-1.5 L at a time 1 to prevent re-expansion pulmonary edema
• Confirm complete lung re-expansion with chest radiograph before proceeding 1, 4

Medication Preparation

Prepare the pleurodesis solution by mixing: 1, 2, 3

• 20 mL of 10% povidone-iodine
• 80 mL of normal saline (total volume 100 mL)
• 2 mg/kg of lidocaine for additional analgesia

Pre-Medication Protocol

Administer before the procedure: 1, 4

• Intravenous narcotic agent
• Anxiolytic-amnestic agent
• Consider instilling lignocaine solution (3 mg/kg; maximum 250 mg) into the pleural space for local analgesia 1

Instillation Procedure

Step-by-step administration: 1, 2, 3

1. Ensure the chest tube is patent and properly positioned 4
2. Instill the prepared povidone-iodine solution through the chest tube when minimal or no pleural fluid remains 1
3. Clamp the chest tube for 1-2 hours after instillation 1, 2, 3—studies show 1 hour 1 to 2 hours 2 clamping times, with 2 hours potentially providing better distribution
4. Patient rotation during the clamping period is recommended 1 to ensure even distribution of the sclerosant, though this is not definitively established for povidone-iodine 1

Post-Instillation Management

After unclamping the chest tube: 1, 4

• Maintain the patient on -20 cm H₂O suction 1, 4
• Monitor daily chest tube drainage volume 1
• Remove the chest tube when 24-hour drainage is <150-200 mL 1, 2—some protocols use <200 mL 2 while others use <100-150 mL 4
• If drainage remains excessive (≥250 mL/24 h) after 48-72 hours, repeat instillation at the same dose 1, 4

Expected Efficacy and Success Rates

Povidone-iodine demonstrates excellent efficacy comparable to talc: 1, 2, 3, 5

• Success rates range from 86.5% to 98.4% 2, 3, 5
• Complete response (no recurrence) achieved in 89.5% of patients 5
• No procedure-related mortality reported in multiple studies 1, 2

While talc remains the guideline-recommended first-line agent with 90-93% success rates 4, povidone-iodine achieves comparable efficacy (88-98%) 1 and is not mentioned in major Western guidelines despite extensive use in other regions 1

Complications and Management

Common adverse effects: 1, 2, 3, 5, 6

• Chest pain occurs in 16-27% of patients 1, 6—most cases are mild and occur immediately after instillation 2
• Fever occurs in approximately 11% 1, 3
• Pleural empyema is rare (<2%) 1, 2 and responds to drainage and antibiotics

Provide adequate analgesia and antipyretics 4 to manage these symptoms. Unlike talc, povidone-iodine demonstrates excellent tolerability with no risk of acute respiratory failure 1

Critical Pitfalls to Avoid

Never attempt pleurodesis without confirming complete lung re-expansion—trapped lung or bronchial obstruction will result in treatment failure 1, 4. Trapped lung occurs in approximately 30% of malignant pleural effusions 1

Avoid corticosteroids at the time of pleurodesis—they reduce pleural inflammatory reaction and increase failure rates 1, 4

Do not remove more than 1.5 L of fluid during initial drainage 1 to prevent re-expansion pulmonary edema

Management of Pleurodesis Failure

If initial pleurodesis fails: 1, 4

• Repeat pleurodesis with the same or different agent 1, 4
• Consider thoracoscopic talc poudrage if initial slurry method was used 1, 4
• Indwelling pleural catheters are preferred over repeat chemical pleurodesis for patients with nonexpandable lung or failed pleurodesis 1
• Repeated thoracentesis for patients with limited life expectancy 1, 4

Advantages of Povidone-Iodine Over Other Agents

Povidone-iodine offers several practical advantages: 1, 2, 3, 5

• Lower cost than bleomycin 1
• Superior success rates compared to bleomycin (90.6% vs 61%) 1
• More readily available than talc in many regions 3, 5
• Does not require multiple administrations like doxycycline often does 1
• No risk of acute respiratory failure unlike small-particle talc 1

However, talc remains superior as first-line when maximum possible success rate is critical and thoracoscopy is planned for diagnostic purposes 1, with extensive guideline support from the American College of Chest Physicians 4 and American Thoracic Society 4