Inserting a Chest Drain

The Safe Triangle

This is a triangle created by:
  • Mid-axillary line / boarder of latissimus dorsi
  • Lateral boarder of pec major
  • Imaginary horizontal line from the nipple
And the drain is usually inserted in the 4th, 5th, or 6th intercostal space

The Procedure

  • Find a location in the safe triangle
  • Alternate locations include 2nd intercostal space mid-clavicular line, and 7th intercostal space, posteriorly, but these are less comfortable for the patient.
  • Using 10-20ml 1% lidocaine inject down at the pleural level, just above the rib (to avoid the neurovascular bundle), usually the 6th rib
  • Then attempt to aspirate air of fluid – if you cant, then don’t insert the drain here! Wait 3 minutes, and try again
  • Then blunt dissect down to the level of the pleura (e.g. using scissors, using the opening action of the scissors to dissect, or using forceps)
  • Puncture the pleura with scissors or forceps
  • If you are using a large bore tube, you may need to insert a finger into your dissect to remove any adherent lung
  • Remove the metal part of the drip before inserting – you should already have done your dissection – don’t force it in!
  • Advance the drain slowly, using forceps if necessary. Stop if you hit serious resistance
  • Attached the other end of the drain to the underwater seal
    • The long tube should be under the water, and should bubble with respiration
  • Medium and large bore tubes may require suturing around the entry site
  • Fix the chest drain in place with a tie around the tube
  • Request CXR to ensure the drain has been placed correctly

Clamping a chest drain

  • This is occasionally performed in the case of pleural effusion, to control the rate of drainage, as draining too fast can result in expansion pulmonary oedema.
  • You should never clamp a chest drain in the case of pneumothorax


  • Trauma / injury to thoracic / abdominal organs
  • Trauma to the long thoracic nerve of bell resulting in wing scapula
  • Arrhythmia (rare)

Things to watch out for

  • Backwards flow of water seal towards chest cavity
  • Prolonged bubbling of the chest drain fluid
  • Blockage of the tube due to kinks, blood clot / other. There will be no ‘swinging’ or ‘bubbling’ in the seal fluid
  • Wrongly positioned chest drain – check the CXR

Removing the tube

  • Check there is re-expansion on CXR
  • In pleural effusion you may want to clamp the drain, as you may want to re-insert it
  • In pneumothorax, clamping is not necessary as reinsertion is unlikely
  • Give the patient a strong analgesic (e.g. morphine)
  • Remove the tube during expiration, and suture the insertion site

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