What is the proper technique for inserting an intercostal (chest) drain?

Intercostal Drain Insertion Technique

For intercostal chest drain insertion, use small-bore drains (10-14 F) as initial treatment, inserted via the "safe zone" technique in the 4th or 5th intercostal space in the mid-axillary line, positioned 50-70% down the interspace to avoid neurovascular structures. 1

Drain Size Selection

Small-bore systems (10-14 F) should be used initially for pneumothorax management, with primary success rates of 84-97% reported. 1 These smaller drains offer:

• Comparable efficacy to larger tubes
• Reduced patient discomfort
• Shorter hospital stays
• Mean drainage time of 2-4 days

The Seldinger technique (catheter over guidewire) is increasingly used and may prove as safe and effective as traditional small-calibre tubes, though more expensive. 1

Consider larger bore tubes only when:

• Pleural fluid is present alongside air
• Large air leak exceeds capacity of smaller tubes 1

Anatomical Positioning

Site Selection

Insert the drain in the 4th or 5th intercostal space in the mid-axillary line. 2

Critical Safety Zone

The neurovascular bundle does NOT reliably sit in the subcostal groove as traditionally taught. Cadaveric studies demonstrate significant anatomical variation. 3

Position the drain 50-70% of the way down the interspace to avoid:

• The variably positioned superior intercostal neurovascular bundle
• The inferior collateral artery 3

This "safe zone" is narrower than historically appreciated—the concept that "there is nothing to damage immediately superior to the inferior rib" is incorrect. 3

Step-by-Step Technique

Pre-Insertion Preparation

1. Use adequate local anaesthetic into the correct space
2. Use a needle first to:
   • Locate the anaesthetized skin
   • Identify the intercostal space
   • Determine depth of pleural cavity 4
3. Understand the purpose of insertion (air vs. fluid vs. both)

Insertion Method

For Seldinger technique (small-bore):

• Pass small (8 F) catheter over guidewire into pleural space
• Attach three-way stopcock
• Can aspirate via 50 ml syringe
• May add Heimlich valve for ambulatory management 1

Critical Technical Points

• Never use a steel trocar—associated with serious complications including hemothorax, lung lacerations, and injury to thoracic/abdominal organs 2
• Meticulous attention to technique is vital to avoid complications 5, 2
• Ensure correct positioning before securing

Post-Insertion Management

Initial Care

Do NOT apply suction immediately after insertion. 1 Early suction, particularly in primary pneumothorax present for several days, may precipitate re-expansion pulmonary oedema.

When to Add Suction

Add suction only after 48 hours if:

• Persistent air leak continues
• Failure of pneumothorax to re-expand 1

Use high-volume, low-pressure systems (-10 to -20 cm H₂O) such as Vernon-Thompson pump or wall suction with pressure adaptor. 1

Avoid:

• High pressure, high volume systems (causes air stealing, hypoxemia, perpetuates air leaks)
• High pressure, low volume systems 1

Specialist Referral Triggers

Refer to respiratory physician if:

• No response within 48 hours
• Persistent air leak >48 hours
• Failure of lung to re-expand 1

Seek thoracic surgical opinion at 3-5 days for persistent problems. 1

Common Pitfalls

1. Anatomical misconception: Assuming the neurovascular bundle is always in the subcostal groove—it varies significantly 3

2. Premature suction: Applying suction immediately risks re-expansion pulmonary oedema 1

3. Oversized drains: Using large-bore drains when small-bore would suffice, increasing patient discomfort without improving outcomes 1

4. Trocar use: Steel trocars cause preventable serious complications 2

5. Inadequate local anaesthesia: Insufficient anaesthetic makes the procedure difficult in distressed patients 4