What are the indications for chest tube thoracostomy (CTT) insertion in patients with empyema?

Indications for Chest Tube Thoracostomy (CTT) Insertion in Empyema

Chest tube drainage should be inserted at the outset for any significant pleural infection, particularly when effusions are enlarging and/or compromising respiratory function, rather than managing with antibiotics alone. 1

Primary Indications for CTT Insertion

Clinical and Radiographic Criteria

• Insert a chest tube when a child remains pyrexial or unwell 48 hours after admission for pneumonia with confirmed parapneumonic effusion/empyema 1
• Effusions that are enlarging on serial imaging require chest tube drainage rather than conservative management 1
• Any effusion causing respiratory compromise (increased work of breathing, hypoxia, respiratory distress) mandates drainage 1
• Moderate to large effusions that are free-flowing should undergo chest tube placement, though proceeding directly with adjunctive fibrinolytic therapy is also reasonable 1

Pleural Fluid Characteristics

• Loculated effusions cannot be drained adequately with antibiotics alone and require chest tube insertion with adjunctive therapy 1
• Frankly purulent pleural fluid (empyema) requires immediate tube thoracostomy drainage 2
• Pleural fluid with positive bacterial cultures in the setting of elevated leukocyte count and fever indicates empyema requiring drainage 3

Important Procedural Considerations

Technical Requirements

• Use ultrasound guidance to confirm the presence of pleural fluid and to guide optimal drain placement 1, 4
• Small-bore chest drains (10-14 F) are recommended over large-bore drains (20-24 F), as there is no evidence that larger tubes provide better outcomes and they cause more patient discomfort 1, 4
• Chest drains must be inserted by adequately trained personnel with a suitable assistant and trained nurse available to reduce complications 1

Safety Measures

• Correct any coagulopathy or platelet defect before insertion when possible 1
• Use full aseptic technique to minimize the risk of secondary infection (empyema rate after chest tube insertion is 1-6%) 1, 3
• Connect the drain to a unidirectional flow drainage system kept below the patient's chest level at all times 4
• Clamp the drain for 1 hour once 10 ml/kg are initially removed to prevent re-expansion pulmonary edema, but never clamp if the tube is bubbling 1, 4

When NOT to Use CTT Alone

Indications for Adjunctive Therapy

• Complicated, loculated effusions require chest tube drainage with intrapleural fibrinolytics (urokinase 40,000 units in 40 ml saline twice daily for 3 days for children ≥10 kg) rather than chest tube alone 1, 4
• If loculation is present on ultrasound, pleural fluid leukocyte count ≤6,400/µL predicts failure of tube thoracostomy alone and warrants early surgical consideration 5

Indications for Surgical Intervention

• VATS should be performed when moderate to large effusions persist with ongoing respiratory compromise despite 2-3 days of chest tube management 1
• Early discussion with a thoracic surgeon is indicated for persisting sepsis, organized empyema, or multiloculated empyema failing medical management 4

Common Pitfalls to Avoid

• Do not perform repeated thoracentesis if significant pleural infection is present—insert a drain at the outset 1
• Do not manage enlarging or respiratory-compromising effusions with antibiotics alone, as this results in prolonged illness and hospital stay 1
• Residual hemothorax after initial chest tube placement increases empyema risk from 2% to 33% and should prompt additional drainage efforts including thoracoscopy 3
• Incomplete drainage of the pleural space and prolonged catheter duration are major risk factors for empyema development 6

Chest Tube Removal Criteria

• Remove the chest tube when there is no air leak and pleural fluid drainage is <1 ml/kg/24 hours (usually calculated over the last 12 hours), typically achieved within 48-72 hours 1