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Anatomy

• Adult trachea is 10-12 cm long and bifurcates at the carina into the left (LMB) and right (RMB) main bronchi.
• Anteriorly, the trachea is supported by cartilaginous semi-circular rings and posteriorly by the trachealis muscle.
• At the carina, the RMB more closely follows the trajectory of the trachea than the LMB, which arises at a steeper angle to the midline.
  • The LMB is narrower and longer than the RMB.
  • The average length of the LMB is 5.3 cm compared with 2.7 cm for the RMB
  • Given the short length of the RMB, care must be taken to prevent the right upper lobe from being inadvertently occluded by the cuff of the bronchial lumen of a right-sided DLT or BB. For this reason, a left-sided DLT is generally preferred over a right-sided DLT.

Double Lumen Tube Vs Bronchial Blockers

Double-lumen Endotracheal Tube

• BMJ video link:
  • https://ars.els-cdn.com/content/image/1-s2.0-S2058534923001063-mmc1.mp4
  • https://ars.els-cdn.com/content/image/1-s2.0-S2058534923001063-mmc2.mp4
• Design
  • PVC, single use, two catheters bonded together side by side, with each lumen intended to ventilate one of the two lungs
  • White or clear tracheal lumen and a blue bronchial lumen
• Sizing
  • French (Fr) gauge system, where 1 Fr 1/3 mm of the outer diameter. Thus, a 37 Fr DLT has an outer diameter of (1/3)x 37= 12.3 mm
  • Available in sizes 26–41 Fr. 37–39 Fr and 39 to 41 Fr are most suited for adult females and males, respectively. Tube size is dictated not only by width of the trachea, but the length of the trachea (patient height is used)
• Types
  • Left-sided and right-sided tubes
    • Refers only to which mainstem bronchus the catheter must be placed in, not to which lung must be ventilated
    • Either the left-sided or right-sided tube can be used for surgery on the left or right lung
    • Left sided DLT’s are more commonly employed than their right sided equivalents (unless significant left sided lung resection, or a left pneumonectomy is planned). This is due to the difficulties in ensuring that the right double lumen tube is correctly positioned to prevent occlusion of the right upper lobe bronchus, which would result in failure to ventilate the right upper lobe, risking intraoperative hypoxia and atelectasis.
• Positioning and initiating OLV
  • When correctly positioned, the tracheal lumen terminates in the distal trachea and the bronchial lumen terminates in the distal main bronchus
  • When initiating OLV, the connector to the operative lung is clamped and the lumen opened to air, allowing ventilation of the non-operative lung and deflation of the operative lung
  • Clinical confirmation of position is incorrect in 48% of cases. 1/10 will dislodge. 1/3 of deaths are due to displacement
  • The DLT is inserted with the bronchial lumen curved anteriorly, and once through the laryngeal inlet, requires a 70-90 degree rotation
  • Advantages
    • They also allow suctioning of individual lungs and the administration of CPAP/PEEP to individual lungs

Sequence of Clinical Check of Correct Placement of a Left-Sided Double-Lumen Tube (DLT)

1. Correct bronchi: Clamp the tracheal lumen and ventilate through the bronchial lumen. The left lung should ventilate. If the right lung ventilates, the DLT has advanced into the right main bronchus.
2. Correct depth: Clamp the bronchial lumen and ventilate through the tracheal lumen. The right lung should ventilate independently and easily.
   • If ventilation of the right lung is met with increased airway resistance, the tube may have advanced too far, obstructing the orifice of the tracheal lumen.
   • If both lungs ventilate, the tube has likely not advanced far enough into the left main bronchus.
3. Check tube position: If the tube is not correctly positioned or cuffs are not sufficiently inflated, bronchoscopy should be performed.
4. Bronchoscopy steps:
   • Advance the bronchoscope to the tip of the tracheal lumen. The carina should be centered on the screen with the trachealis muscle identified posteriorly.
   • The left main bronchus should appear on the left with a blue bronchial cuff visible. The right main bronchus should be on the right.
   • Advance the bronchoscope into the right main bronchus until the origin of the right upper lobe bronchus is seen on the top right of the screen.
   • Advance the bronchoscope into the right upper lobe bronchus to identify the three sub-segmental bronchi.

Indications for a Right-Sided Double Lumen Tube

Surgery involving the left main bronchus

• Left pneumonectomy
• Left lung transplant
• Left tracheobronchial disruption
• Left-sided thoracoscopic surgery

Distorted anatomy of the left main bronchus

• Aneurysm of descending thoracic aorta
• Tumour compression of left main bronchus

Placement of DLT

1. Tube selection

• Select the largest DLT that fits the bronchus
  a. Males: 41 Fr for most males 39 Fr for small stature males
  b. Females: 37 Fr for most females, 35 Fr for small stature females

2. Preparation
   a. Fully deflate both cuffs before insertion.
   b. Lubricate the outside of the tube to reduce the risk of damage during insertion.
   c. Lubricate the bronchoscope with aqueous gel to aid its smooth passage through the tube
   d. With the stylet in place, bend the distal 10 cm of the DLT 60 degrees anteriorly. This manoeuvre aids tracheal intubation and minimises the risk of rupturing the tracheal cuff as it passes over the patient’s teeth.
3. Placement through cords
   a. The DLT has 2 curves–anteroposterior, and a 2nd curve of the bronchial tube (left or right)
   b. With the bronchial tip directed anteriorly, advance the tip of the tube just through the vocal cords. Remove the stylet
4. Rotation
   a. Turn the DLT sufficiently to rotate the tip to 90 from the midline to help advance the tube past the thyroid cartilage.
   • Left-sided DLT: rotate anticlockwise
   • Right-sided DLT: rotate clockwise
   • In some circumstances, rotation through 180 degrees may be required to pass the thyroid cartilage.
   • If a 180 rotation was needed rotate the DLT 90 degrees in the opposite direction so that the bronchial lumen aligns with the appropriate bronchus.
5. Advance the tube
   a. Advance until resistance is felt, avoiding excess force.
   • The average depth of insertion in a 170 cm adult is 29 cm, plus or minus 1 cm for each 10 cm increase or decrease in height
   • When advancing the tube, turning the patient’s head in the opposite direction to the bronchus being intubated helps the tube advance into the correct bronchus.
6. Confirm correct placement and inflate cuffs
   a. Inflate both cuffs. Consider measuring the cuff pressure (normal pressure 20-40 cmH2O, avoid pressure >40 cm H2O).
   b. Perform clinical and bronchoscopic checks to confirm the DLT is correctly positioned and lung isolation has been successful.
   • Clinical
     • The tube is connected to the anaesthetic circuit, and the tracheal cuff inflated until there is no air leak, and bilateral chest movement and air entry is confirmed by auscultation. Take note of the peak airway pressures at this time
     • The tracheal lumen is opened, and the fresh gas flow to it clamped.
     • The bronchial cuff can now be inflated, until no air leak is felt at the tracheal opening during ventilation
     • Auscultation is used to ensure good air entry at the apex and base of the lung unilaterally, and confirmed deflation of the contra lateral lung. Airway pressures are also noted. There should be a rise of no more than 8 to 12 cmH20 in peak airway pressure.
     • Ventilate both lungs again.
     • Now open the bronchial lumen, and clamp its fresh gas flow inlet.
     • Tracheal ventilation is then initiated, which is confirmed by unilateral air entry on auscultation and unilateral chest expansion.
     • If there is a rise in airway pressure greater than 12 cmH20, or there is reduced air entry to the non-bronchial lumen it suggests the bronchial cuff is causing obstruction (by herniation across the carina) and needs to be inserted further.
   • The bronchial cuff is deflated and auscultation is repeated.
   • If there is no difference in air entry or if there is NO change in airway pressures on deflation of the cuff it suggests the tube is abutting the carina or the tracheal portion of the tube is endobronchial, and the tube should be slightly withdrawn
7. Deflate operative lung
   a. Clamp the soft silicone connector between the breathing system and the DLT on the operative lumen and release the bung on the connector

Bronchial Blockers

• BMJ video link:
  • https://ars.els-cdn.com/content/image/1-s2.0-S2058534923001063-mmc3.mp4
• Used in combination with a standard single-lumen tracheal tube. Rely on fibreoptic bronchoscopy to visualise placement of a balloon tipped catheter into the appropriate bronchus
• The bronchial blocker is passed along with the endotracheal tube during the initial intubation and then guided into the appropriate mainstem bronchus
• Sizing
  • A 9 Fr blocker is suitable for most adults. Use at least a size 8 ETT

Placement of BB

1. Preparation
   • Assemble and check the multiport airway adapter. Lubricate and place the bronchoscope and blocker into their respective ports
   • The blocker hub has a tightening screw, leave this loose at this point.
2. Pass through cords
   • Intubate the patient’s trachea and confirm ventilation of the lungs.
3. Position ETT and insert BB
   • Use the bronchoscope to position the tip of the tube 1 cm from the carina and identify the right and left main bronchi
   • Manually thread the bronchoscope tip through the loop of the blocker.
   • Connect the multiport airway adapter to the tracheal tube.
   • Connect the breathing system to the side port. Tighten the blocker hub to prevent air leak
4. Advance to carina and place BB in bronchus
   • Advance the bronchoscope to the carina, identifying the trachealis muscle posteriorly. Verbally confirm the side you intend to block and advance the bronchoscope down the chosen bronchus.
   • Untighten the hub and advance the blocker down the trachea and into the bronchus.
   • Withdraw the bronchoscope to the carina to visualise both bronchi and confirm the position of the blocker within the chosen bronchus.
   • Note the depth on the blocker and secure the mount and blocker hub
5. Confirm position and deflate lung
   • To deflate the lung, disconnect the breathing system in expiration and inflate the BB cuff under bronchoscopic view (6-12 ml of air).
   • Confirm the inflated cuff is correctly positioned in the proximal bronchus.
   • If not inserted sufficiently far into the bronchus, inflating the cuff can cause the cuff to herniate into the trachea.
   • Reconnect the breathing system and withdraw the inner wire of the blocker
   • If repositioned then note new depth
   • Correct position needs to be reconfirmed with every patient movement

Advantages and Disadvantages

Double-lumen Tube

• Advantages:
  • Quicker to place
  • Can alternate ventilation to either lung
  • Fiberoptic bronchoscope not essential
• Disadvantages:
  • Limited sizes available
  • Difficult to place correctly when anatomy is distorted or abnormal
  • Not ideal if postoperative ventilation needed
  • Higher risk of causing airway trauma

Bronchial Blocker

• Advantages:
  • Easy size selection
  • Usable with a standard tracheal tube, useful in patients already intubated or with tracheostomy
  • Used with single-lumen tube, easier for difficult intubation
  • Selective lobar isolation possible
  • Easily withdrawn if postoperative ventilation required
• Disadvantages:
  • Takes longer to insert
  • Fiberoptic bronchoscope essential
  • Suction of isolated lung not as effective
  • Bronchoscopy of isolated lung not easy
  • Difficult to alternate side of OLV (except with certain blockers like Rusch EZ-Bifid)
  • More prone to intraoperative displacement

Surgical Considerations

• Indications for right sided DLT
  1. Surgery involving the LMB (e.g. left pneumonectomy, left lung transplant, repair of left-sided tracheobronchial disruption).
  2. Proximal obstruction of the LMB
  3. Severe distortion of the LMB (e.g. thoracic aortic aneurysm, enlarged left atrium)
• If neither right of left sided tube can be used
  • One option is to use a left-sided DLT and withdraw the tube before transecting the LMB, ensuring that the tip of the bronchial lumen is entirely within the distal trachea. This option should be discussed with the surgeon before starting the procedure

Predicting Difficult Airway and OLV

• Upper airway
  • Normal approach
  • Previous surgery or radiotherapy involving the head and neck is NB to note
• Lower Airway
  • Chest CT
    1. Distortion of the trachea or bronchi from external compression
    2. Obstruction of the trachea or bronchi from direct tumour invasion.
    3. The effects of previous thoracic surgery
    4. The presence of a tracheal bronchus
    5. The presence of a tracheostomy
• A small DLT or a single-lumen tube with a BB may be needed if there is compression of a bronchus. A DLT may be difficult to advance past an obstruction, particularly when the obstruction is within the airway
• With previous lung resection, the remaining lung parenchyma expands to fill the space, potentially distorting the bronchus on the affected side.
• A tracheal bronchus is defined as an abnormal bronchus arising anywhere from the cricoid cartilage to the carina. Tracheal bronchus occurs in up to 2% of the population and is more common on the right than the left side.
  • A DLT can be used in the presence of a tracheal bronchus but care must be taken to ensure the orifice of the tracheal bronchus is not obstructed by the tracheal cuff of the DLT.
    • Alternatively, two BBs can be used, with one inserted into the main bronchus and one into the tracheal bronchus.

Trouble Shooting

Malpositioning

• Avoiding malpositioning:
  • Bronchoscopy assessment identifies a third of malpositions not identified clinically and malposition predicts hypoxaemia during OLV
  • A common error is confusing the tracheal carina with more distal bifurcation
  • DLTs sizes 35-41 Fr were able to accommodate a 4 mm (outer) diameter bronchoscope
• Diagnosing malpositioning
  • Lung isolation is successful if each lung can be ventilated at appropriate volume (4-5mlkg) and pressure (<25-30 cmH2O).
  • Malposition results in some combination of
    • (i) high airway pressure
    • (ii) failure to deflate or persistent ventilation of the operative lung
    • (iii) circuit leak
    • (iv) an abnormal capnograph
    • (v) impaired gas exchange
  • The commonest malposition is when the bronchial lumen has not passed sufficiently far into the bronchus. The clinical findings depend on the position of the tip of the bronchial lumen, the operative side and whether the bronchial cuff has been hyperinflated
  • Advancing the tip of the DLT too far into the bronchus typically results in high airway pressure, an obstructed capnograph trace and evolving hypoxaemia
  • If the orifice of the tracheal lumen lies within a bronchus, the operative lung will not deflate
  • When the DLT is too small for the patient there is a risk of advancing the tube too far into the bronchus during insertion. However, when correctly positioned, a small tube may require hyperinflation of the bronchial lumen to achieve lung isolation, which increases the risk the cuff will herniate into the trachea. The need for >3 ml air in the bronchial cuff suggests cuff herniation
• When the DLT appears to be correctly positioned but there is persistent ventilation or non-deflation of the operative lung, the likely causes include
  (i) Insufficient air in the bronchial cuff allowing ventilating gas to leak into the operative side.
  (ii) Ventilation of the bronchial lumen at high pressure, such that gas bypasses the bronchial cuff. Reducing the ventilatory pressure or adding more air to the bronchial cuff mitigates this problem.
  (iii) Secretions and blood in the airway. Suctioning secretions along with gentle surgical manipulation may facilitate deflation of the operative lung

Clinical Signs and Management Strategies of Malposition of a Left-Sided Double-Lumen Tube (DLT)

When repositioning a DLT, both cuffs should be deflated.

Incorrect Side

Type of Malposition:

• The bronchial lumen is positioned in the right-main bronchus instead of the left.

Clinical Features:

• OLV of the bronchial lumen results in ventilation of the right lung.
• OLV of the tracheal lumen results in ventilation of the left lung.

Management:

• With the bronchoscope down the bronchial lumen, withdraw the DLT until the carina comes into view. Then, advance the tip of the bronchial lumen down the LMB.
• With the bronchoscope down the tracheal lumen, check the DLT is correctly positioned by visualizing the carina and the orifice of the right upper lobe bronchus.

Correct Bronchus but Tip Too Shallow

Type of Malposition:

• The tip of the bronchial lumen is in the LMB but the bronchial cuff lies partly or entirely within the trachea.

Clinical Features:

• OLV of the bronchial lumen results in incomplete or failed lung isolation. There may be an air leak from the tracheal lumen.
• OLV of the tracheal lumen results in incomplete or failed lung isolation. If the bronchial lumen obstructs the distal trachea, it may be difficult or impossible to ventilate the right lung.

Management:

• With the bronchoscope down the tracheal lumen, the tracheal wall is visible through the orifice of the tracheal lumen. The orifice of the bronchial lumen is not typically obstructed.
• With the bronchoscope down the bronchial lumen, advance the DLT further into the LMB.
• Repeat bronchoscopy down the tracheal lumen confirming the tube is correctly positioned and the bronchial cuff lies completely within the LMB.

Correct Bronchus but Tip Too Deep

Type of Malposition:

• The tip of the bronchial lumen is advanced too far into the LMB. The orifice of the tracheal lumen lies partly or completely within the bronchus and is obstructed.

Clinical Features:

• Ventilating the bronchial lumen ventilates the left lung but ventilation to the left upper lobe may be poor or non-existent. Airway pressure may be high, and the patient may become hypoxaemic.
• Ventilating the tracheal lumen results in obstruction with high airway pressure and the rapid development of hypoxaemia.

Management:

• With the bronchoscope down the tracheal lumen, the wall of the LMB is visible. The orifice of the tracheal lumen is typically obstructed.
• With the bronchoscope down the tracheal lumen, withdraw the DLT until the carina and the right upper lobe bronchus comes into view.

Difficulty Advancing the Double-lumen Tube into the Trachea

• Common
  • Rotating helps
  • Cuff integrity must be checked with each attempt at intubation

Other

• Airway trauma
  • Double-lumen tube cuffs should be deflated whenever the tube is repositioned
  • When using a hyperangulated blade, the DLT must be bent more than is usual to conform to the shape of the blade
• Awake
  • First place a single-lumen tracheal tube using a recommended technique
  • Once a single-lumen tube is in place, there are two options for lung isolation. The safest and our preferred method is to use a BB.
  • Alternatively, a DLT can be placed using an exchange catheter. The exchange catheter should be long enough to accommodate the DLT and have a diameter that is small enough to fit down the bronchial lumen of the DLT. The 11 Fr 100cm Cook Airway Exchange Catheter (Cook Medical) is suitable for 35 Fr and larger DLTs.
  • Exchange over an intubating bougie is not recommended, as shearing and disintegration of the bougie has been reported.
  • The bronchoscopy-guided Aintree exchange catheter (Cook Medical) cannot be used for tube exchange, as the catheter diameter is too large to pass through a DLT
• Tracheostomy
  • Our practice for bag-mask ventilation is to use a supraglottic airway over the stoma. In most patients the distance from the stoma to the carina is too short to accommodate a standard DLT, in which case a single-lumen tube and a BB is the best option for lung isolation. Patients with a temporary tracheostomy inserted as a component of their ICU management may not have a well formed stoma. Removing the tracheostomy may lead to loss of control of the patient’s airway. Options in this circumstance are to (i) place a BB through the tracheostomy or (ii) place a DLT via the orotracheal route

Summary of Troubleshooting and Malposition Management of Double-Lumen Tubes

Issue	Clinical Features / Diagnosis	Management Strategy
General Malpositioning	– 1/3 missed clinically without bronchoscopy – High airway pressures, abnormal capnograph, circuit leak, failure to deflate lung	– Use bronchoscopy for confirmation – Check ventilatory volumes and pressures – Reposition if needed
DLT Too Shallow (Bronchial cuff in trachea)	– Failed lung isolation – Tracheal lumen air leak – Poor ventilation of right lung	– Advance DLT into bronchus under bronchoscopic guidance – Confirm bronchial cuff lies entirely within LMB
DLT Too Deep (Tracheal lumen in bronchus)	– Poor upper lobe ventilation – High airway pressures, hypoxaemia – Tracheal lumen obstructed	– Withdraw DLT until carina and RUL bronchus visible via bronchoscopy
Wrong Side (Bronchial lumen in RMB)	– Bronchial lumen ventilates right lung – Tracheal lumen ventilates left lung	– Withdraw DLT until carina seen – Redirect bronchial lumen into LMB
Persistent Ventilation/Non-deflation	– Bronchial cuff underinflated – High pressure ventilation bypassing cuff – Airway obstruction from secretions/blood	– Add air to cuff or reduce ventilation pressure – Suction airway – Gentle surgical manipulation
Tube Too Small	– Risk of deep insertion and cuff herniation – >3 mL air in bronchial cuff suggests herniation	– Select appropriate size DLT – Minimize cuff inflation volumes
Airway Trauma Risk	– From repeated repositioning or excessive cuff pressure	– Always deflate cuffs before repositioning – Pre-shape DLT to match laryngoscope blade if hyperangulated
Awake Intubation	– Awake DLT placement difficult	– Use single-lumen tube first, then (i) insert bronchial blocker (preferred), or (ii) exchange to DLT over 11 Fr 100cm Cook AEC
Tracheostomy Patients	– Short trachea often can’t accommodate DLT	– Use BB through tracheostomy or – Insert DLT via orotracheal route if feasible – Avoid removing tracheostomy if not well formed
Difficulty Advancing DLT	– Common issue with tight airways	– Rotate DLT during advancement – Check cuff integrity after each attempt

Links

• One lung Ventilation and VATS
• Open chest and Empyema
• Shared airway

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References:

1. Patel, M., Wilson, A., & Ong, C. (2023). Double-lumen tubes and bronchial blockers. BJA Education, 23(11), 416-424. https://doi.org/10.1016/j.bjae.2023.07.001
2. Campos, Javier H. MD. An Update on Bronchial Blockers During Lung Separation Techniques in Adults. Anesthesia & Analgesia 97(5):p 1266-1274, November 2003. | DOI: 10.1213/01.And.0000085301.87286.59

Summaries:

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Copyright
© 2025 Francois Uys. All Rights Reserved.

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