How should I flush an intercostal drainage (ICD) tube?

Flushing an Intercostal Drainage (ICD) Tube

If your intercostal chest drain becomes blocked or drainage ceases, flush it with 20-50 mL of normal saline to restore patency. 1

When to Flush an ICD

• Flush the drain when it becomes blocked or when pus/fluid is unable to drain effectively 1
• Regular saline flushes significantly reduce blockage rates in pleural effusions (odds ratio 0.04 for blockage in flushed vs non-flushed drains, P < 0.001) 2
• After flushing, if poor drainage persists, obtain imaging (chest X-ray or CT scan) to check drain position, look for kinks, tube distortion, or undrained loculated fluid 1

Flushing Technique

Use 20-50 mL of normal (0.9%) saline for each flush 1

Step-by-Step Procedure:

• Perform hand hygiene and maintain aseptic technique throughout 3
• Ensure the drain clamp is closed before disconnecting any connections 3
• Clean the hub with chlorhexidine (or povidone if chlorhexidine not tolerated) using the "scrub-the-hub" technique 3
• Attach a syringe containing 20-50 mL of normal saline to the drain 1
• Unclamp the drain 3
• Gently flush the saline through the drain—avoid excessive force 1
• A gentle back-and-forth motion (irrigate) may help promote patency 3
• After irrigation, use a turbulent flushing technique to ensure blood and debris are cleared from the lumen 3
• Reclamp the drain after flushing 3
• Reconnect to the drainage system 3

Critical Safety Points

• Never use excessive force when flushing—this risks chest penetration and damage to intrathoracic structures 4
• Do not contaminate the flush solution with local anesthetic or heparin, as this can affect pleural fluid chemistry 5
• Keep the drainage system below the level of the patient's chest at all times 4
• Never clamp a bubbling chest drain (indicates ongoing air leak or pyopneumothorax) 6
• If the drain remains blocked after flushing, it should be removed and a new drain inserted if indicated 1

Troubleshooting Non-Functioning Drains

Before assuming the drain is blocked:

• Check for external causes of resistance: ensure clamps are open, look for kinks in the tubing, and assess patient positioning 3
• Verify the drain hasn't been displaced ("fallen out")—this occurs in 21% of small-bore drains 2
• Assess for respiratory swing in the drainage tubing, which confirms proper pleural positioning 4
• Consider fibrin sheath formation or thrombus if problems persist despite flushing 3

Common Pitfalls

• Inadequate training in chest drain troubleshooting leads to inappropriate management, including unnecessary additional drain insertions 7
• Blockage rates are significantly higher without regular flushing (9% blockage rate overall, reduced to near-zero with regular flushes) 2
• Failure to maintain sterile technique increases infection risk (empyema occurs in 1-6% of chest tube insertions) 6